MRFT Issue 1 - Home - P&B -- P&B Assignment of the Output Relays for MRFT.....20 6.4 INDICATION OF...

MRMF Technical Manaual P&B Engineering

Issue P 23/6/99

Publication applicable to relays supplied from January 1996 onwards Serial no : 96****

MRFT Frequency Protection Relays

P&B Engineering

Belle Vue Works

Boundary Street

Manchester

M12 5NG

Tel: 0161 230 6363

Fax: 0161 230 6464

E-mail [email protected]


Issue P 23/6/99

Contents

1. INTRODUCTION ..............................................................................................................................................................1

2. APPLICATION ..................................................................................................................................................................2

3. FEATURES AND CHARACTERISTICS........................................................................................................................2

4. DESIGN...............................................................................................................................................................................3

4.1 CONNECTIONS .................................................................................................................................................................3

4.1.1 Analogue input circuits............................................................................................................................................3

4.1.2 Output relays ...........................................................................................................................................................3

4.1.3 Blocking Input .........................................................................................................................................................4

4.1.4 Remote data communication ...................................................................................................................................7

4.2 FRONT PANEL ..................................................................................................................................................................7

4.2.1 Display.....................................................................................................................................................................7

4.2.2 LED indicators ........................................................................................................................................................9

4.2.3 Push buttons ............................................................................................................................................................9

4.3 CODE JUMPERS ................................................................................................................................................................9

4.3.1 Password programming ........................................................................................................................................10

4.3.2 Alarm and Trip relay function ...............................................................................................................................10

5. WORKING PRINCIPLES ..............................................................................................................................................11

5.1 ANALOGUE CIRCUITS .....................................................................................................................................................11

5.2 DIGITAL CIRCUITS ..........................................................................................................................................................11

5.3 POWER SUPPLY ..............................................................................................................................................................11

5.4 VOLTAGE SUPERVISION (MRMF, MRVT) ..............................................................ERROR! BOOKMARK NOT DEFINED.

5.4.1 Delta/Star Connection of the Input Transformers ....................................................Error! Bookmark not defined.

5.5 FREQUENCY SUPERVISION .............................................................................................................................................12

5.5.1 Measurement Principle of Frequency Supervision................................................................................................12

5.6 VECTOR SURGE SUPERVISION .......................................................................................................................................12

5.6.1 Vector Surge Supervision Inhibit...........................................................................................................................13

5.6.2 Vector Surge Supervision Measurement Principles ..............................................................................................14

5.6.3 df/dt Measurement Principles................................................................................................................................16

5.7 TRIP METHOD FOR LOSS OF MAINS [LOM] ...................................................................................................................16

6. OPERATION AND SETTING........................................................................................................................................17

6.1 LAYOUT OF THE CONTROL ELEMENTS ............................................................................................................................17

6.2 RELAY SETTING PRINCIPLES ...........................................................................................................................................17

6.2.1 Password protected parameter adjustment ...........................................................................................................18

6.3 SETTING PROCEDURE .....................................................................................................................................................18

6.3.1 Under and Over Voltage Setting ...........................................................................................................................18 6.3.1.1 Voltage Supervision Threshold ..........................................................................................................................................19

6.3.1.2 Voltage Supervision Time Delay........................................................................................................................................19

6.3.2 Under and Over Frequency Setting.......................................................................................................................19 6.3.2.1 Frequency Supervision Threshold ......................................................................................................................................19

6.3.2.2 Frequency Supervision Time Delay [Please see 6.3.2.3]....................................................................................................19

6.3.2.3 Number of Cycles Setting (T).............................................................................................................................................19

6.3.2.4 Frequency Rate Setting (df/dt) ...........................................................................................................................................19

6.3.3 Vector Surge Setting ..............................................................................................................................................20 6.3.3.1 Vector Surge Threshold......................................................................................................................................................20

6.3.4 Nominal frequency.................................................................................................................................................20

6.3.5 Voltage Inhibit Level .............................................................................................................................................20

6.3.6 Assignment of the Output Relays for MRFT .........................................................................................................20

6.4 INDICATION OF MEASURED VALUES AND FAULT DATA ...................................................................................................21


Issue P 23/6/99

6.4.1 Indication of measured values...............................................................................................................................21

6.4.2 Indication of fault data ..........................................................................................................................................21

6.5 TEST TRIP......................................................................................................................................................................22

6.6 RESET............................................................................................................................................................................22

6.6.1 Hand reset .............................................................................................................................................................22

6.6.2 Auto-reset at Power Up .........................................................................................................................................22

6.7 SETTING VALUE CALCULATION ......................................................................................................................................22

7. RELAY CASE ..................................................................................................................................................................22

7.1 INDIVIDUAL CASE ..........................................................................................................................................................22

7.2 RACK MOUNTING ...........................................................................................................................................................22

7.3 TERMINAL CONNECTIONS ..............................................................................................................................................22

8. TEST AND MAINTENANCE.........................................................................................................................................23

9. TECHNICAL DATA........................................................................................................................................................23

9.1 MEASURING INPUT CIRCUITS.........................................................................................................................................23

9.2 AUXILIARY POWER SUPPLY............................................................................................................................................23

9.3 COMMON DATA .............................................................................................................................................................23

9.4 SETTING RANGES AND STEPS..........................................................................................................................................24

9.5 OUTPUT CONTACT RATINGS ...........................................................................................................................................26

9.6. TYPE TESTS ..................................................................................................................................................................27

9.7 HOUSING .......................................................................................................................................................................30

9.8 TERMINAL CONNECTION DETAILS .................................................................................................................................31

10. ORDER FORM ..............................................................................................................................................................32


023/6/99 Page 1 MRMF 01/97 O

1. Introduction

The application of powerful microprocessors opens a new chapter for power system protective

relaying. The digital processing of measured values and the ability to perform complex arithmetic and

logic operations, give digital protection relays significant performance and flexibility improvements

over their traditional analogue counterparts. Additional advantages - very small power consumption,

adaptability, self-supervision, fault diagnosis through fault data recording, smaller physical

construction and selectable relay characteristics - all combine to allow the implementation of accurate

and highly reliable protection schemes at a significantly reduced financial burden.

The development of microprocessor based protective relays and their introduction into the market has

been stimulated by the recent trend to replace analogue with digital equipment. This modern trend has

prompted the development of a new P&B protective relay family - the MR relay series. This

comprehensive family of protection relays can satisfy the demands of even the most complex

protection schemes:

MRI - Overcurrent Relay (Independent time/I.D.M.T + earth + directional facilities)

MRI-V - Voltage Dependent Overcurrent Relay

MREF - Restricted Earth Fault Relay

MRAR - Auto-Reclosing Relay

MRMF - Mains Failure Relay

MRVT - Voltage Protection

MRFT - Frequency Protection

MROS - Vector Surge or Rate of Change of Frequency

MRNS - Negative Sequence Relay

MRRP - Power Relay

MRCS - Check Synchronising Relay

MRFF - Field Failure Relay

MRDG - Differential Relay

The superiority of digital protective relaying over traditional analogue devices, as embodied by the

MR relay family, is summarised by the following features:

•••• Integration of many protective functions in a single compact case

•••• High accuracy owing to digital processing

•••• Digital relay setting with very wide setting ranges and fine setting steps

•••• Comfortable setting procedure through extensive human - relay dialogue

•••• Measured values and fault data indication by means of alpha-numeric display

•••• Data exchange with DCS/SCADA by means of RS485

•••• Operational reliability through self-supervision

A similar but simplified range, with reduced functions and without display, is also available. The

MIRI - overcurrent and earth fault relays, and the MIRV - undervoltage, overvoltage and neutral

voltage displacement relays. To complement the MR series, a range of Auxiliary, Timing and

Tripping devices are also available.


023/6/99 Page 2 MRMF 01/97 O

2. Application

The MRFT relay is a mains decoupling relay that covers the protection requirements of most utilities

for the mains parallel operation with co-generation schemes. The protective functions of the MRFT

are summarised as follows:

•••• Two stage independent Over and Under Frequency Protection

• Integrated df/dt

3. Features and characteristics

• Complete digital processing of the sampled measured values.

• Digital filtering of the measured values by using discrete Fourier analysis to suppress the high

frequency harmonics and dc component induced by faults or system operation.

• Extremely wide setting ranges with fine setting steps

• Unauthorised user access control through password protection

• User defined password.

• Continuous self-supervision of software and hardware.

• Outstanding design flexibility for easy selection of appropriate operational scheme for

numerous applications

• Numerical display of setting values, actual measured values and memorised fault data etc.

• Serial data communication facilities via RS485.

• Wide voltage range for DC or AC power supply.

• Withdrawable modules with automatic short circuit of C.T. inputs.


023/6/99 Page 3 MRMF 01/97 O

4. Design

4.1 Connections

Application Diagram; MRFT

POWER

SUPPLY

1 2 CASE

Supply

MRFTTypical Earthing Shown

54 5553External Reset Blocking Input

L N L

ALARM/TRIP SIGNAL 133

31

29

32

3034

4852

50

45

43

41

44

4246

40

38

36

37

3539

+

7 9 10

Gnd-

4751

49

SELF SUPERVISION

RS485

15

V1

L1

L2

L3

16

ALARM/TRIP SIGNAL 2

ALARM/TRIP SIGNAL 3

ALARM/TRIP SIGNAL 4

4.1.1 Analogue input circuits

The constantly monitored measuring values are galvanically decoupled, filtered and finally fed to the

analogue/digital converter. The protection unit receives these analogue input signals of the voltages

via separate input transformers.

4.1.2 Output relays

The MRFT has five output relays, with single or dual pole change-over contacts as detailed in the

previous diagram and summarised below:

• Alarm / Trip 1 (2)




• Self-supervision alarm relay (1)


023/6/99 Page 4 MRMF 01/97 O

4.1.3 Blocking Input

Various functions of the relay will be blocked if the auxiliary voltage is connected between terminals

54 and 55. This is summarised in Table 4.1.3.1. It may be noted that a number of blocking functions

may be programmed on the MRMF1 & MRMF2, to selected parameters to be blocked, the <ENTER>

& <TRIP> buttons should be depressed simultaneously, the message ‘BLOC’ or ‘NO-B’ is displayed

along with the protection function LED illuminated RED i.e. V<, V>, etc.

By using the <value up> & <value down> push buttons, block or no block may be selected. This may

be stored by using the <ENTER> button and entering the correct password. The remaining protection

functions may be selected in the same manner by stepping through, using the <SELECT/RESET>

push buttons.


21/07/2010 Page 6 Issue P

Table 4.1.3.1

Event V</<< V>/>> F1 F2 F3 ∆∆∆∆θθθθ df/dt

1 Auxiliary Voltage

applied to blocking

input

Blocked Blocked Blocked Blocked

3 Auxiliary Voltage

removed from

blocking input

Unblocked Unblocked

after 1 sec

Unblocked

after 5 secs

After 5 sec

4 Auxiliary Voltage

applied to relay

auxiliary

Blocked for

200ms

Blocked for

200ms

Blocked for

1 sec.

Blocked for

1 sec.

Blocked for

1 sec.

5 Application of all

three measurement

voltages

Unblocked Unblocked Blocked for

1 sec.

Blocked for

5 sec.

Blocked for

5 sec.

5 Loss of one or more

measurement

voltage(s)

Operate

providing

function enabled

Operate

providing

function enabled

Blocked* Blocked* Blocked*

7 Measurement voltage

below inhibit level

5100% Un adjustable

Operate

providing

function enabled

Operate

providing

function enabled

Blocked Blocked Blocked

*Note : Single or 3 phase operation is available on the MRMF and MROS



4.1.4 Remote data communication

As an option, the MRFT can have an RS485 interface for remote data communication with a control

centre. The unit provides the following information:

• Status signals

• Self supervision alarm signal

• Actual measured values

• Relay settings

• Fault signalling

4.2 Front panel

The front panels of the MRFT comprise the following operation and indication elements:

• Alphanumeric display

• 5 push buttons for setting and other operations

• Up to 17 LEDs for measured value indication and setting

4.2.1 Display

The measured and set values, and recorded fault data, are shown alphanumerically on the display. The

meaning of the displayed values is easily interpreted from the LED indicators on the front panel.

Front Panel MRFT

SELECT

RESET

VALUE

VALUE

ENTER

TRIP

P&B

U f dF

RSMaxMin

MRFT

TFn

Ub R

Fe

F

dF

tF1

tF2

tF3

1

F2

F3

dt

F4

1

dF2

tF4

dt

1

2

PB



Table: Adjustment possibilities by means of the display

Display

Information

Display Shows Pushbutton, System

Reply

Illuminated LED Type

Operating Values Actual Frequency

Measurement

Actual Frequency

Rate Measurement

<SELECT>

<SELECT>

F, MIN, MAX

df

MRFT

MRFT

Fault Data Frequency

Frequency Rate

<SELECT>

<SELECT>

F1 F2 F3 [F4]

df

MRFT

MRFT

Setting Values Rated Frequency

Measurement rate

Threshold for

f1 f2 f3 f4

Time delay for

f1 f2 f3 f4

Threshold for the

Frequency Rate df

in Hz

Trip Time for

Frequency Rate dt

<SELECT>, <∧>, <∨>

<SELECT>, <∧>, <∨>

<SELECT>, <∧>, <∨>

<SELECT>, <∧>, <∨>

<SELECT>, <∧>, <∨>

<SELECT>, <∧>, <∨>

Fn

T

F1 F2 F3 F4

tF1 tF2 tF3 tF4

df

tdf

MRFT

MRFT

MRFT

MRFT

MRFT

MRFT

MRFT

Block Function

EXIT <SELECT>, <∧>, <∨> LED of parameter

to be blocked

Normal Operation "P&B" Long <RESET> All Units

Password Inquiry "PSW?" <ENTER>/<TRIP> All Units

Save Parameter ""SAV?" <ENTER> All Units

Parameter Saved "SAV" <ENTER> All Units

Manual Trip/Test "TRI?" <TRIP> All Units

Relay Tripped "TRIP" <TRIP> All Units



4.2.2 LED indicators

The LEDs left of the display indicate measuring or tripping values. The purpose of the corresponding

LED is to be identified according to the inscription above the LEDs (e.g. f, for frequency).

All LEDs are bi-coloured LEDs, the green indicating measuring and the red for fault indication.

The LED marked with the letters RS, is used to indicate serial data communication. The LED lights if

the serial interface is active.

4.2.3 Push buttons

The front panel contains five push buttons used for setting, measuring and other user functions.

The individual setting and measuring values can be selected in turn by pressing the <SELECT> /

<RESET> push button. This button also resets the relay if pressed for approximately 3 seconds.

The <UP> and <DOWN> push buttons are for incrementing and decrementing any selected

parameter. Continuous pressing of these push buttons will cause the parameter to change at an

increased rate.

The <ENTER> push button is used to transfer the indicated value to the internal parameter memory.

An unintended or unauthorised change of the selected parameter can be avoided through the password

protection facility.

The <TRIP> push button is used to test the output relay circuits, both for tripping and signalling. This

operation is also password protected.

4.3 Code jumpers

Behind the front panel of the MRFT are three code jumpers used to pre-set the following functions:

•••• Password programming

•••• Alarm and Trip relay functions

The following figure shows the position and designation of the code jumpers

J3 J2 J1

Code Jumper ON

Code Jumper OFF

Front Board

Code Jumper


21/07/2010 Page 10 Issue P

4.3.1 Password programming

The MRFT relays are normally delivered with the pre-set password "∧∧∧∧", they can be

reprogrammed using the removable code jumper J1. After power on and the pressing of any push

button, the MRFT relay enquires for a new password with the text <PSW?> appearing on the

display. A new password is then entered by pressing a combination of <SELECT>, <UP>,

<DOWN> or <ENTER>, as chosen by the user. After the new password has been given, the relay

module is extracted from its case and code jumper J1 removed.

4.3.2 Alarm and Trip relay function

The following function of the MRFT relays may be pre-set using jumper J3.

•••• Manual or Automatic reset of the output relays

Code jumper J3 - OFF

All output relays will be reset automatically after tripping, once the fault has been cleared.

Code jumper J3 - ON

All output relays remain activated and must be reset manually by pressing the <RESET> push

button, after the fault has been cleared.

Summarising the coding possibilities

Code jumper Function Code jumper Position Operation Mode

J1 Password OFF

ON

Normal position

Password programming

J2 Not used OFF

J3 Reset OFF

ON

Output relays will be reset

automatically.

Output relays will be reset

manually.


21/07/2010 Page 11 Issue P

5. Working principles

5.1 Analogue circuits

The incoming voltages from the external voltage transformers are converted to internal signals in

proportion to the voltages, via the internal input transducers and shunt resistors. The noise signals

caused by inductive and capacitive coupling are suppressed by an analogue RC filter circuit. The

analogue signals are fed to the A/D converter of the micro-processor and transformed to digital

signals through sample-hold circuits. The analogue signals are sampled with a sampling frequency of

16 × the fundamental frequency, namely a sampling rate of 1.25 mS for every measured quantity at

50Hz.

5.2 Digital circuits

The essential component of the MRFT relay is a powerful micro-controller. All of the operations,

from the analogue digital conversion to the relay trip decision, are carried out by the micro-controller

digitally. The relay program, located in EPROM, allows the CPU of the micro-controller to calculate

the voltage values in order to detect a possible fault.

For the calculation of the measured values, an efficient digital filter, based on the Fourier Analysis

(DFFT - Discrete Fast Fourier Transformation), is applied to suppress high frequency harmonics and

DC components caused by fault induced transients or other system disturbances. The actual calculated

values are compared with the relay settings. When a measured value exceeds the starting value the

unit starts the corresponding time delay calculation. When the set time delay has elapsed, a trip signal

is given.

The relay setting values for all parameters are stored in EEPROM, so that the actual relay settings

cannot be lost, even in the event of auxiliary supply interruption. The micro-processor is supervised

through a built in "Watch-dog" timer. Should a failure occur the watch-dog timer resets the micro-

processor and gives an alarm signal via the self supervision output relay.

5.3 Power supply

Two auxiliary power supply versions are available:

Vaux = 24V in a range from 16V to 60V AC

or in a range from 16V to 80V DC




21/07/2010 Page 12 Issue P

5.4. Frequency Supervision

The MRFT has their applications in over and under frequency protection for generators and other

electrical equipment’s. The relay is equipped with four multiple stage independent over frequency and

under frequency protection, each with separate time and frequency settings.

5.4.1 Measurement Principle of Frequency Supervision.

The principle behind frequency supervision is based upon the time taken for a complete cycle, the

influence of harmonics is therefore minimised.

TU(t)

To avoid tripping during normal operation due to voltage transients or phase transients, the MRFT

relay is equipped with an adjustable repeat measurement function. Each cycle where the pre-set

threshold is reached, an internal counter is increased until the set point of the repeat measuring

function is reached; at this point the relay trips. With each cycle without any fault the counter is

decreased and for the case of normal operation the counter is decreased to zero. In the case of very

low input voltages (5-100% of Un adjustable), the frequency measuring is automatically inhibited to

avoid failure tripping. This same inhibit may also take place (and continues for 1 second) when the

auxiliary supply or measuring voltage is initially switched on.

5.5. Vector Surge Supervision

Vector surge supervision protects synchronous generators in parallel operation from faults by very

fast decoupling. In the case of mains failure where the mains voltage could return in 300mS, this

could hit the generator in asynchronous mode which can be very dangerous. The same fast decoupling

is also necessary in the case of transients. Generally there are two different applications:

1. Mains Parallel Operation without Island Operation - In this application the vector surge

supervision protects the generator by tripping the generator circuit breaker in the case of mains

failure.

2. Mains Parallel Operation with Island Operation - In this application the vector surge supervision

trips the mains circuit breaker insuring that the gen-set is not blocked when required as the

emergency set.

Very fast decoupling in the case of mains failures for synchronous generators is difficult to achieve as

voltage supervision alone cannot be used. This is because the synchronous alternator as well as the

unit impedance supports the decreasing voltage. Because this voltage reaches the threshold of the


21/07/2010 Page 13 Issue P

voltage supervision after 200mS, safe detection for auto-reclosing of the mains is not possible with

single voltage supervision units.

Also frequency relays alone cannot be used, as even a fully overloaded generator decreases in speed

after 100mS. Current protection relays can detect the fault by the existence of short circuit currents as

can power sensing relays but neither can avoid the decreasing change of power to short circuit power.

A further problem is the failure tripping of these devices due to the sudden change in the loading of

the generator.

The MRMF relay can detect mains failure in less than 60mS due to its specialised design for this

specific application. The total tripping time is within 150mS even when the circuit breaker time and

the relay time are taken into consideration. A change in power of only 10% or more will cause the

relay to trip whereas slow changes in the system frequency such as controlling of the governor will

not cause the relay to trip. A short circuit in the mains may also trip the relay if a vector surge higher

than the pre-set threshold is detected. The value of the vector surge is dependent upon the distance of

the short circuit in the generator. This function has the advantage of that the mains short circuit

capacity and hence the energy feeding the short circuit can be limited.

5.6.1 Vector Surge Supervision Inhibit

Vector surge supervision should only be used in mains parallel operation. In single operation the

auxiliary supply must be switched to the blocking input, terminals 54 and 55.

Blocking

Time Delay 5s

Vector Surge Function Deactivated Activated

Vector surge supervision can be inhibited without any time delay. Removal of the inhibit will become

effective after a time delay of 5 seconds.

For further details refer to Table 4.1.3.1.


21/07/2010 Page 14 Issue P

5.6.2 Vector Surge Supervision Measurement Principles

When a synchronous machine (generator) is under load, the terminal voltage (relaying point) differs

from the actual generator internal voltage. This volt drop results from current flow through the

internal generator impedance (and external impedance if fitted). A simplified phasor diagram of a

generator exporting power, at a slightly lagging p.f., is shown in Figure 5.6.2.1.

Figure 5.6.2.1

It should be noted that a leading power factor will still produce an angular difference V between

phasors.

If the current is reduced to zero (say by a breaker trip), then Vg and Vterm would become co-phasor

(as shown in Figure 5.6.2.2) since Vdrop would no longer be present. A vector shift of V would be

"seen" by the protection relay, and if above the setting level would initiate a trip.

Figure 5.6.2.2


21/07/2010 Page 15 Issue P

Where a generator provides power in parallel with a mains supply infeed, as shown in Figure 5.6.2.3,

any loss of mains supply, say through a distant outage, will cause an increase in the load "seen" by the

generator. This change of load will again cause a vector shift. If the shift is in excess of the set value

the relay will trip.

Figure 5.6.2.3

Typically a current of approximately 5% of Full Load with typical generator parameters will produce

sufficient phasor shift for reliable operation and a mid-range setting.

The phasor shift effect is shown in Figure 5.6.2.4, on a voltage-time base. The cycle time is compared

with a quartz clock reference. A phasor shift will cause a change in the zero crossing point which will

in turn cause a trip of the relay if the trip angle ∆Θ has been exceeded.

Figure 5.6.2.4

0Time →

V [t]

↑ V1 ' [t]

"Vector Shift"

V1 [t]

→ ←

∆Θt∆ ⇒

Trip


21/07/2010 Page 16 Issue P

5.6.3 df/dt Measurement Principles.

When a synchronous machine (generator) is under any load, the mechanical power provided by the

prime mover supplies the electrical output of the machine, the machine losses and the stored energy

contained within the rotating mass.

If a sudden change in load occurs the electrical output of the machine changes, whilst in the short

term both the mechanical power and the losses remain approximately unchanged.

This change in power therefore produces a net acceleration or deceleration in the rotating mass. The

rotational velocity of the mass is directly related to the frequency of the generated voltage. Thus an

increase or decrease of the system frequency (df/dt) can be directly related to a sudden change of load

on a machine. This can usually be attributed to a loss of mains supply, where either the load is

reduced giving an increase in speed of the machine or an additional load (other grid loads etc.) where

a decrease in speed of the machine may be noted.

The setting of df/dt is dependant upon

1] The normal export / import level of the generator / grid arrangement.

2] The inertia of the machine (or inertia constant H).

3] The type of motion imparted by the primary mover. i.e. if a diesel (reciprocating) engine is

used the pulsating torque may produce significant df/dt under normal but high load conditions.

A typical setting of df/dt for a stiff system with little normal export of power and large machine

inertia is df/dt = 0.2 Hz / sec

A typical setting of df/dt for a weak system with considerable normal export of power and a low

machine inertia is df/dt = 0.4 Hz/sec.

For reciprocating drives a figure guided by the above recommendations but modified to insure that no

spurious operation takes place due to the nature of the prime mover is typical.

5.7 Trip Method for Loss of Mains [LOM]

The trip logic is selectable in the MRMF-1 and the MROS, between single or 3 phase detection.

When single phase is chosen ANY one phase detecting a vector surge ∆θ will result in a Trip action.

When three phase is chosen ALL three phases must detect a vector surge ∆θ in order to obtain a Trip

action.


21/07/2010 Page 17 Issue P

6. Operation and setting

6.1 Layout of the control elements

All control elements required for the operation and adjustment of the MRMF are located on the front

panel. They are divided according to function into the three following groups:

• Alphanumeric Display: Indication of parameter set values, actual measured values and recorded

fault data.

• LED's: Indication of selected parameters and measured quantities.

• Push Buttons: Selection of parameter to be adjusted, quantity to be measured and

adjustment of parameter values. Where;

<SELECT / RESET> Selection of the parameter to be set and the relay quantities to

be measured. Continuous pressing as the reset function.

<UP> Increment of the setting values for the parameter selected.

<DOWN> Decrement of the setting values for the parameter selected.

<ENTER> Storage of the setting values for the selected parameter.

<TRIP> Testing of the output relay circuits.

6.2 Relay setting principles

There are up to twenty one relay parameters which can be set by the user, depending on relay type;

U< Undervoltage Threshold

U<< Undervoltage Threshold (Highset)

U> Overvoltage Threshold

U>> Overvoltage Threshold (Highset)

tU< Undervoltage Time Delay

tU<< Undervoltage Time Delay (Highset)

tU> Overvoltage Time Delay

tU>> Overvoltage Time Delay (Highset)

F1 Threshold for Frequency element 1

tF1 Trip Time for Frequency element 1







T Measurement rate

df Frequency Rate Threshold

dt Measurement rate of df/dt

Dθ Vector Surge Threshold

1/3 Trip 1 from 3 or 3 from 3

Vb Blocking Voltage

RS Serial Interface No

By pressing the <SELECT/RESET> push button, the parameter to be modified is reached. The

corresponding LED illuminates on the curve and the present set value of the selected parameter is

indicated on the display. This set value may then be increased or decreased by pressing the <UP> or

<DOWN> buttons respectively. The selected set value is only stored after pressing the <ENTER>

push button and inputting the correct password. This means that adjustment of the unit is only

possible by authorised users.


21/07/2010 Page 18 Issue P

6.2.1 Password protected parameter adjustment

The adjustment of all relay settings are password protected, however, to enable ease of adjustment, for

authorised users, application of the password is usually only required once for multiple parameter

adjustment. The following step by step sequence is given to illustrate the implementation of the

password protection facility, where a new relay setting is to be applied:

• After the present setting value has been selected and changed using the <UP>,

<DOWN> push buttons, the <ENTER> push button should be pressed.

• The message <SAV?> appears on the display, to confirm that the new setting value is

to be saved.

• After pressing <ENTER> again, the password will be requested. The message

<PSW?> is displayed.

• After the password has been given correctly, as indicated by the message <SAV!>, the

new setting value may be stored by pressing the <ENTER> push button for at least 3

seconds. The new setting parameter then reappears on the display.

A password consists of four push button operations. The pressed push buttons and their sequence

define the password. If the four push buttons are defined by the following symbols:

<SELECT> = S

<DOWN> = ∨∨∨∨

<UP> = ∧∧∧∧

<ENTER> = E

Then a password "∨∨∨∨E∧∧∧∧S" is achieved by the following sequence:

<DOWN> <ENTER> <UP> <SELECT>.

After a password is given correctly, parameter setting is permitted for five minutes. Subsequent

parameter setting made within the five minute period after the password was inputted, does not

require renewed password entry. Furthermore, the valid period for parameter setting is automatically

extended for a further 5 minutes after each push button operation.

If no push button is pressed within the 5 minute period then the validity of the password will be

suspended. To enter further parameters after this period re-application of the password is required.

During the 5 minute period when changes may be made, a new set value, acknowledged by <SAV?>

then <SAV!> , may be stored by pressing <ENTER> for approximately 3 seconds.

6.3 Setting procedure

In this section the setting of all relay parameters is described in detail:

6.3.1 Under and Over Voltage Setting

The setting procedure is guided by two coloured LED's. During the setting of the voltage thresholds,

the LED's U<, U<<, U>, U>> are lit green. During the setting of the time delays tU<, tU<<, tU>,

tU>> the LED's are illuminated red.


21/07/2010 Page 19 Issue P

6.3.1.1 Voltage Supervision Threshold

During the setting of the voltage thresholds for U<, U<<, U>, U>> the display shows the value in

volts. These can be changed to the required value by use of the <UP>, <DOWN> and <ENTER>

keys. All these settings can be inhibited by setting to the "EXIT" value.

6.3.1.2 Voltage Supervision Time Delay

During the setting of the Time Delays tU<, tU<<, tU>, tU>> the display shows the value in seconds.

These can be changed to the required value by the use of the <UP>, <DOWN> and <ENTER> keys in

the range of 0.04 to 50 seconds.

6.3.2 Under and Over Frequency Setting

The setting procedure is guided by two coloured LED's. During the setting of the frequency

thresholds, the LED's F1, F2, F3, [F4] are lit green. During the setting of the time delay tF1, tF2, tF3,

[tF4] the LED's are lit red.

6.3.2.1 Frequency Supervision Threshold

The setting procedure for the thresholds of tF1, tF2, tF3, [tF4] are similar to those described in 6.3.1.1.

6.3.2.2 Frequency Supervision Time Delay [Please see 6.3.2.3]

The setting procedure for tF1, tF2, tF3, [tF4] are similar to those described in 6.3.1.2.

6.3.2.3 Number of Cycles Setting (T)

During the setting of the number of cycles T, this figure (2 - 99) is displayed. This can be changed by

using the <UP>, <DOWN> and <ENTER> keys. Selection of this value has an important bearing on

the Trip time of the frequency elements, these may be set from 0.06- 50s, however are bounded by a

lower limit.

This is For T in the range 2-49 Tmin = (T + 1) x .20mS

For T in the range 50-69 Tmin = [(T + 1) x 50mS] + 1secs

For T in the range 70-99 Tmin = [(T-69) x 100mS] + 2 sec

For both 50 and 60 Hz relays.

For short trip times i.e. during machine protection or mains failure applications a value between 2 & 5

should be selected for T, giving a low limit of 60mS - 120mS.

For accurate measurements then a larger value for T should be selected. For a setting T = 10 the

fastest trip time would be 220mS for 50Hz

6.3.2.4 Frequency Rate Setting (df/dt)

During the setting of the frequency rate df, the display shows the value in Hz/s. The set value is

changed via the <UP>, <DOWN> and <ENTER> keys in the range of 0.2 to 10Hz/s.


21/07/2010 Page 20 Issue P

6.3.3 Vector Surge Setting

The recommended setting of the vector surge angle Dθ in a power mains with low mains impedance

is 6°. This setting is sufficient in most cases as power mains do not have a vector surge higher than

this value. In the case of an auto-closing system this value can be exceeded. In low power mains with

a higher mains impedance then the setting should be 10° to 12° to avoid tripping when switching on

or off large loads. The vector surge function can be set using the following criteria:

1. Generator in single operation - Switching on and off of loads (approx. 20% of nominal generator

capacity) must trip the relay. Later in normal operation the tripping of the relay is inhibited.

2. In mains parallel operation - Switching on and off of loads and controlling the governor of the

prime mover should not trip the relay.

If possible the above should be double checked by a real auto-reclosing operation.

6.3.3.1 Vector Surge Threshold

When the value of the vector surge is set, a value in angular degrees is displayed. This value can be

adjusted in the range of 2° to 22° by use of the <UP>, <DOWN> and <ENTER> keys. During this

procedure the DQ LED is lit.

6.3.4 Nominal frequency

The FFT Algorithm employed requires the nominal frequency as a parameter for correct digital

filtering of the input currents. Alternatively the frequency may be self supervised.

By pressing <SELECT> the display shows "f=50", "f=60" or "VARI". The desired nominal

frequency may then be selected and stored.

6.3.5 Voltage Inhibit Level

Certain relay functions are blocked when the measurements voltage falls below its inhibit level, see

table 4.1.3.1, this level Vb is selectable in the range 6-100% Un.

6.3.6 Assignment of the Output Relays for MRFT

Output relays 1-4 of the MRFT are normally off and can be assigned as alarm or tripping relays to the

frequency functions. the assignment of the output relays is similar to the setting of parameters,

however, only whilst in the assignment mode. By pressing push buttons <ENTER> and <TRIP>

simultaneously, the assignment mode is selected.

The assignment of the relays, may be adjusted as follows : LEDs F1, F4 are bi-coloured and are

illuminated green when the output relays are assigned as alarm relays and red as tripping relays. By

definition the alarm relays are activated after elapse of the tripping delay.

Note : The jumper J2 has no function for the MRFT

After the assignment mode has been activated, first LED R is illuminated red and LED F1 is

illuminated green. Now one or several of the four output relays can be assigned to frequency element

F1 as alarm relays. At the same time the selected alarm relays for frequency element 1 are indicated

on the display. Indication ‘1_ _ _’ means that output relay 1 is assigned to this frequency element.

When the display shows ‘_ _ _’, no alarm relay is assigned to this frequency element. The assignment

of output relays 1 - 4 to the frequency elements can be changed by pressing value up and valuedown


21/07/2010 Page 21 Issue P

push buttons. The selected assignment can be stored by pressing push button <ENTER> and

subsequent input of the password. By pressing push button <SELECT>, LED F1 is illuminated red.

The output relays can now be assigned to this frequency element as tripping relays.

Relays 1-4 are selected in the same way as described above. By repeated pressing of the <SELECT>

push button and assignment of the relays all frequency, df/dt elements and undervoltage lockout can

be assigned separately to the relays. The assignment mode can be terminated at any time by pressing

the <SELECT> push button for approximately 3 seconds. For the df/dt elements the relays can only

be assigned as tripping relay, then LEDs df1 and df2 are illuminated red in connection with LED R.

EXAMPLE

Relay function Outputs relays Display-

indication

LED : Colour

1 2 3 4

F1 alarm X 1 _ _ _ F1 : green

tripping _ _ _ _ F1 : red

F2 alarm _ _ _ _ F2 : green

tripping X _ 2 _ _ F2 : red

F3 alarm X 1 _ _ _ F3 : green

tripping X _ 2 _ _ F3 : red

F4 alarm _ _ _ _ F4 : green

tripping _ _ _ _ F4 : red

df1/df1 tripping X _ _ 3 _ df1 : red

df2/df2 tripping X _ _ _ 4 df2 : red

V8 alarm _ _ _ _ V8 : green

6.4 Indication of measured values and fault data

6.4.1 Indication of measured values

Any one of the following measured quantities may be indicated on the display during normal service

by pressing the <SELECT> button:

•••• Voltages - LED's L1, L2 and L3 are green

•••• In Star Connection - All 3 Phases and Neutral

•••• In Delta Connection - All 3 Phases

•••• Frequency - LED f is green

•••• Vector Surge - LED DQ is green

The relevant operating values of the individual measured quantities are indicated in the display. The

shown measured values refer to the rated current.

6.4.2 Indication of fault data

Visual indication of faults detected by the relay is given on the front panel. The L1, L2, & L3 LEDs

are used to indicate/specify fault events.

When a relay function is initiated by a fault, the corresponding function LED lights up yellow. At the

same time , the phase LED(s) flash(es) red to indicate the faulty phase(s). When the time delay is

reached, the relay is tripped, the LED(s) for the faulty phase(s) turn to a constant red. The function

LED remains alight.


21/07/2010 Page 22 Issue P

After the occurrence of a trip, fault data may be displayed by repeatedly pressing the <SELECT>

key. After all faults been indicated, the LEDs return to red indicating the fault event. By pressing the

<SELECT/RESET> button for approximately 3 seconds the relay is reset to its original status. If

however, the relay was initiated by the occurrence of a fault, which then fell below a detectable level,

a slowly flashing LED is displayed. This can also be reset using the <SELECT/RESET> button.

6.5 Test Trip

The whole tripping circuit of the protection system may be tested by simulating a fault with the

<TRIP> push button. This button is also used to interrogate the relay for its software version number.

A single press reveals the first half of the software version number and a second press reveals the

second half. A third press will be responded to by <PSW?>. Entering the correct password will be

responded to by <TRI?> . Pressing <TRIP> again energises all output relays in turn with a delay

time of 1 second. All relays will stay energised until manually reset. This operation overrides any

blocking functions.

6.6 Reset

There are two ways in which to reset the MRMF relay:

6.6.1 Hand reset

By pressing the <SELECT/RESET> for approximately 3 seconds the relay is reset.

6.6.2 Auto-reset at Power Up

After loss of supply voltage and upon its reconnection the unit resets itself and displays P&B.

This resetting of the unit does not effect the set parameters which are stored in an EEPROM.

6.7 Setting value calculation

In order to ensure that protection relays form an integral part of any system, a full protection co-

ordination study should normally be undertaken which considers both upstream and downstream

equipment. Further details may be obtained by contacting P&B Engineering.

7. Relay case

The MRMF is delivered in an individual case for flush mounting.

7.1 Individual case

The MRMF is supplied in a UK manufactured industry standard drawout case suitable for flush

mounting. For case dimension and cut-out, refer to Technical Data.

7.2 Rack mounting

MRMF relays may be supplied mounted in 19" racks if specified by the user.

7.3 Terminal connections

The MRMF plug in module is supplied in a case which has a very compact plug and socket

connector.


21/07/2010 Page 23 Issue P

8. Test and maintenance

For testing the voltage supervision function the input transformers are injected with a test voltage. By

changing the test voltages and measuring the tripping time the voltage supervision can be tested. For

testing of the frequency supervision function the voltages connected to the input transformers have to

be as near as the value of Un as possible. By changing the frequency of this test voltage and

measuring the trip time the frequency supervision can be tested. A portable test case can be supplied

which is suitable for testing the MRMF.

All measuring input circuits of the MRMF are of static design and the relay functions are fully

digitised. Thus, the MRMF has no particular demand on maintenance.

9. Technical Data

MRMF - Mains Decoupling Relay

MRVT - Voltage Relay

MRFT - Frequency Relay

MROS - Generator/Mains Monitor Relay

9.1 Measuring Input Circuits

Rated Data

Rated voltage, Vn 100V, 230V or 400V

Rated frequency, fn 40 - 70Hz

Power consumption

Voltage circuit < 1 VA

Withstand

Voltage Circuit 2 x Vn

Blocking of frequency measurement Below 11%

9.2 Auxiliary power supply

Two versions of power supplies are available:





Power Consumption

Quiescent @ 24V and 110V - Approx. 3W

Operating @ 24V and 110V - Approx. 6W

9.3 Common data

Drop Off/Pick Up ratio >97% for U>; <103% for U<

>99.99% for f>, <100.02% for f<

Drop Off time 30mS

Time Lag error ±10mS

Interruption Time 50mS, after which data may be lost

Factors effecting delay times:- No influences could be measured.


21/07/2010 Page 24 Issue P

9.4 Setting ranges and steps

MRMF-1

Function Parameter Setting range / step Tolerance

U</U<< U</U<<

tU<

tU<<

(Vn = 100) 2 - 200V / 1V, (EXIT = Blocked)



0.04 - 50s (EXIT) /

0.01; 0.02; 0.05; 0.1; 0.2; 0.5; 1.0; 2.0

± 1% or ±0.3V

± 1% or ± 15mS

U>/U>> U>/U>>

tU>

tU>>




0.04 - 50s (EXIT) /

0.01; 0.02; 0.05; 0.1; 0.2; 0.5; 1.0; 2.0

± 1% or ±0.3V

± 1% or ± 15mS

Frequency 50/60Hz 50-60Hz

Frequency Rate T 2 - 99 Cycles

F1 - F3

tF1 - tF3

F1 - F3

tF1 - tF3

30 - 49.99 Exit 50.01 - 70Hz / 0.1; 0.01 Hz (50Hz)

40 - 59.99 Exit 60.01 - 80Hz / 0.1; 0.01 Hz (60Hz)

0.06 - 50s (EXIT) /

0.01; 0.02; 0.05; 0.1; 0.2; 0.5; 1.0; 2.0s (EXIT = ¥)

±0.005Hz

± 1% or ± 15mS

DQ DQ 2° - 22° (EXIT) / 1° (EXIT = BLOCKED) ± 5% from set value

Vector Surge 1 / 3 phase

Voltage Inhibit Vb 5-100%

MRMF-2


U</U<< U</U<<

tU<

tU<<




0.04 - 50s (EXIT) /

0.01; 0.02; 0.05; 0.1; 0.2; 0.5; 1.0; 2.0

± 1% or ±0.3V

± 1% or ± 15mS

U>/U>> U>/U>>

tU>

tU>>




0.04 - 50s (EXIT) /

0.01; 0.02; 0.05; 0.1; 0.2; 0.5; 1.0; 2.0

± 1% or ±0.3V

± 1% or ± 15mS



F1 - F3

tF1 - tF3

F1 - F3

tF1 - tF3

30 - 49.99 Exit 50.01 - 70Hz / 0.1; 0.01 Hz (50Hz)

40 - 59.99 Exit 60.01 - 80Hz / 0.1; 0.01 Hz (60Hz)

0.06 - 50s (EXIT) /

0.01; 0.02; 0.05; 0.1; 0.2; 0.5; 1.0; 2.0s (EXIT = ¥)

±0.005Hz

± 1% or ± 15mS

df/dt df

tdf

0.2 - 10Hz

2 - 64 cycles



21/07/2010 Page 25 Issue P

MRVT


U</U<< U</U<<

tU<

tU<<




0.04 - 50s (EXIT) /

0.01; 0.02; 0.05; 0.1; 0.2; 0.5; 1.0; 2.0 (EXIT = ¥)

± 1% or ±0.3V

± 1% or ± 15mS

U>/U>> U>/U>>

tU>

tU>>




0.04 - 50s (EXIT) /

0.01; 0.02; 0.05; 0.1; 0.2; 0.5; 1.0; 2.0 (EXIT = ¥)

± 1% or ±0.3V

± 1% or ± 15mS

MRFT




F1 - F4

tF1 - tF4

F1 - F4

tF1 - tF4

30 - 49.99 Exit 50.01 - 70Hz / 0.1; 0.01 Hz (50Hz)

40 - 59.99 Exit 60.01 - 80Hz / 0.1; 0.01 Hz (60Hz)

0.06 - 50s (EXIT) /

0.01; 0.02; 0.05; 0.1; 0.2; 0.5; 1.0; 2.0s (EXIT = ¥)

±0.005Hz

± 1% or ± 15mS

Threshold and

trip value for

dF/dt element

Fe1

Fe2

40 - 49.99 VARI 50.01 - 60Hz [50Hz]

50 - 59.99 VARI 60.01 - 70Hz [60Hz]

40 - 49.99 VARI 50.01 - 60Hz [50Hz]

50 - 59.99 VARI 60.01 - 70Hz [60Hz]

df/dt df1

tdf1

10 - 0.2Hz EXIT 0.2 - 10Hz

1 - 64 cycles

.1Hz

df/dt df2

tdf2

10 - 0.2Hz EXIT 0.2 - 10Hz

1 - 64 cycles


Output Relay R

MROS


DQ DQ 2° - 22° / 1° ± 5% from set value



21/07/2010 Page 26 Issue P

9.5 Output contact ratings

Number of relays = 5

Contacts = contacts for trip relays as detailed in application diagrams

1 change over contact for self supervision relays

Maximum breaking capacity

250V AC / 1500VA / continuous current 6A

for DC voltage:

ohmic L/R = 4ms L/R = 7ms

300 V DC 0.3 A / 90 W 0.2 A / 63 W 0.18 A / 54 W

250 V DC 0.4 A / 100 W 0.3 A / 70 W 0.15 A / 40 W

110 V DC 0.5 A / 55 W 0.4 A / 40 W 0.2 A / 22 W

60 V DC 0.7 A / 42 W 0.5 A / 30 W 0.3 A / 17 W

24 V DC 6 A / 144 W 4.2 A / 100 W 2.5 A / 60 W

Max. rated making current: 64A(IEC65)

mechanical life span: 3 × 106 operating cycles

electrical life span: 2 × 105 operating cycles at 220 V AC / 6A

Contact material Silver Cadmium Oxide (AgCdO)


21/07/2010 Page 27 Issue P

9.6. Type Tests

F1 Functional Tests

Internal Design

Specifications &

IEC60255-6

IEC60255-3

Performance in line with Specification &

Standards

Climatic Tests

C1 Temperature Dry Cold

(Relay operational)

IEC60068-2-1 -20 deg C , 96 hours

C2 Temperature Dry Cold

Transportation & Storage

IEC60068-2-1 -40 deg C, 96 hours

C3 Temperature Dry Heat

(Relay operational)

IEC60068-2-2 70 deg C, 96 hours

C4 Temperature Dry Heat

Transportation & Storage

IEC60068-2-2 85 deg C, 96 hours

C5 Damp Heat Steady State

(Relay operational)

IEC60068-2-3 93% @ 40 deg C , 56 days

Enclosure

C6 Enclosure IEC 529 front IP52 , rear IP00

Mechanical (Relay operational)

M1 Vibration IEC60255-21-1 Class I

Vibration response (relay operational)

10Hz~150Hz - peak displacement 0.035mm

below 58/60Hz,0.5g above ,1 sweep cycle in

each axis

Vibration endurance (relay de-energised)

10Hz~150Hz 1g , 20 sweep cycles in each

axis(160 minutes at 1 octave /min)

M2 Shock & Bump IEC60255-21-1 Class I

Shock response (relay operational) 5g 11mS 3

pulse in each axis

Shock withstand (relay de-energised) 15g 11mS

3 pulses in each axis

Bump (relay de-energised) 10g 16mS 1000

pulses in each axis

M3 Seismic IEC60255-21-1 Class I

Method A single axis sine sweep

1Hz~35Hz – below 8/9Hz 3.5mm peak

displacement horizontal axis, 1.5mm vertical

axis

above 8/9Hz 1g horizontal,0.5g vertical

1 sweep cycle in each axis


21/07/2010 Page 28 Issue P

Electrical E1 Insulation resistance

>100MΩ

IEC60255-5 500 Vdc , 5 sec between all terminals & case

earth, between terminals of independent circuits

including contact circuits and across open

contacts

E2 DC & AC Supply Voltage

(Relay operational)

IEC60255-6 Voltage range, upper & lower limit continuous

withstand , ramp up & down over 1 minute

E3 Voltage Dips , Short

Interruptions & Voltage

variations immunity

(Relay operational)

IEC60255-11

IEC 1000-4-11

3 dips & 3 interruptions at 10 sec intervals of

duration between 10mS and 500mS at zero

crossings & at other points on wave

variation:100% to 40% over 2s,hold for 1s,return

to 100% over 2s

E4 Ripple in dc supply

(Relay operational)

IEC60255-11 12% ac ripple

E5 Dielectric Test (Relay de-

energised)

No breakdown or flashover

Test voltage 45~65Hz

sinusoidal

Or with dc voltage at 1.4x the

stated ac values

IEC60255-5 Series C of table 1 2.0 kV 50Hz , 1 minute

between all terminals & case earth

2.0 kV 50Hz , 1 minute between terminals of

independent circuits including contact circuits.

1.0 kV 50Hz , across open contacts , 1 minute.

E6 High Voltage Impulse

(Relay de-energised)

IEC60255-5 5 kV peak 1.2/50uS,0.5J - 3 positive , 3 negative

between all terminals to case earth

between independent circuits

E7 VT input Thermal Withstand 2x Vn , continuous

E9 Contact performance &

endurance tests

IEC60255-14,15

IEC60255-23


21/07/2010 Page 29 Issue P

Electromagnetic Compatibility R1 Electrical fast Transient/Burst

(Relay operational)

IEC60255-22-4

IEC601000-4-4

Class IV-4.0kv All Circuits.

1 minute each polarity

R2 Oscillatory Waves

1 Mhz Burst

(Relay operational)

IEC60255-22-1 Class III

longitudinal 2.5 kVpeak , 2sec between

independent circuits & case earth

transverse 1.0 kVpeak , 2sec across

terminals of the same circuit

R3 Electrostatic Discharge

(Relay operational )

IEC60255-22-2 Class III

15kV air discharge with cover in place , 8 kV

contact with cover removed - 10 discharges ,

both polarities at 1 sec intervals

R4 Conducted Disturbance

RF fields

(Relay operational)

IEC61000-4-6 0.15 to 80 Mhz

Severity Level 10Vrms

+sweeps 0.05-0.15MHz & 80-100MHz

R5 Radiated e-m field

from digital portable telephones

(Relay operational)

ENV 50204 900 & 1890mhz at 10V/m

R6 Radiated RF e-m field immunity test

(Relay operational)

IEC60255-22-3 Class III test method A

+sweep 500-1000mhz

or IEC 1000-4-3 80-1000mhz

severity 10V/m 80% modulated 1 kHz

R7 Surge Immunity capacitively

coupled

(relay operational)

IEC61000-4-5

Class 5

Test level 4

short circuit combination wave generator

1.2uS/50uS open circuit

8uS/20uS short circuit ,+ & - polarity

phase shifting 0~360o ac line phase angle

repetition rate 1 per minute

Power supply, ct & vt circuits –

4kV common mode 2 ohm source

2kV differential mode 12 ohm source

Output relays 42ohm source

Comms 2 ohm screen to earth only

R8 Power Frequency Magnetic Field

(Relay operational)

IEC61000-4-8 1000A/m for 1 sec

100A/m for 1 minute

in each of 3 axes

R9 Power Frequency Interference on

communications circuits

(Relay operational)

EA TS48-5

class 3, Table 2,

Appendix A(i)

For circuit length 100-1000 metres (0.1%

unbalanced)

R10 Power Frequency interference on

other circuits except 50 Hz inputs

(Relay operational)

EATS 48-5

Appendix A(ii)

All output contact circuits.

R11 Pulse Magnetic Field

(Relay operational)

IEC 1000-4-9 6.4/16uS , 1000A/m

R14 Conducted & Radiated RF

Interference Emission

(Relay operational)

EN55022 or

EN55011or

EN50081-2

IEC60255-25

Class A interference limits

R15 Power frequency, conducted

common mode

IEC 1000-4-16

IEC60255-22-7

D.C. to 150kHz Test Level 4

300V at 16 2/3Hz and 50Hz

Weight = Approx 2Kg


21/07/2010 Page 30 Issue P

9.7 Housing

Throughout the MR series range a modular housing system has been employed, utilising the latest

high quality UK manufactured industry standard case components. This approach affords maximum

flexibility for both the relay scheme designer and the maintenance engineer. The relay modules are

fully withdrawable for ease of maintenance and where applicable incorporate automatic short-

circuiting CT connections to avoid dangerous open circuit CT overvoltages. A clear plastic front

cover is provided for inspection purposes.

MRMF units are supplied in standard height (179mm≅7in.) cases, complying with IEC 297 size 4U.

The rigid case wall is manufactured from a single sheet of hot dipped galvanised steel coated

externally with Plastisol PVC and internally with a low gloss alkyd paint finish. This construction

technique provides improved thermal transfer characteristics over plastic walled cases and combines

exceptional corrosion and flame resilience with good electromagnetic and electrostatic screening

properties allowing many relays to be freely situated in close proximity and hazardous environments.

When the relay is inserted a leaf spring along the top edge of the module makes contact with a solidly

bonded nickel plated steel strip on the interior of the case, providing excellent earth continuity. This

strip is brought out at the rear of the case, above the terminal block, where it forms a separate earthing

terminal. A rigid front mounting flange is provided allowing the entire range of standard cases to be

flush mounted without alteration. These flanges are also used to mount the relay inspection cover

which is secured by thumbscrews. Securely bonded channels can be provided on the top and bottom

surfaces toward the rear of the case allowing large rigid assemblies to be created by the use of joining

strips located in these channels.

This uniform but highly flexible housing system integrates excellent mechanical strength with good

electrical practice in industry standard sizes.

PANEL CUT OUT FLUSH

MOUNTING FIXING DETAILS

4 HOLES 4.4mm DIAMETER

99

168 159

52 23.5

10

97

45

PUSH BUTTON

PROJECTION 10mm

NOT SHOWN TO SCALE

103

177

212

Clearance

25 min

157

32

OPTIONAL

OPTIONAL

OPTIONAL

Min28

NOTE Minimum gap between vertical

spacing is required in order to

withdraw relay from the case above.

178

Required to open case SIZE 100 CASE


21/07/2010 Page 31 Issue P

9.8 Terminal Connection Details

The rear terminal block accepts both pre-insulated screw and push-on blade type connectors which

may be used singly or in combination. Each terminal has 1 screw type and 2 blade type connectors.

Screw: Each connection uses a 4mm (M4) screw outlet and accepts standard

L-shaped ring type connectors designed for 4mm screws.

Blade: Each connection facilitates 2 pre-insulated push-on blades 4.8mm

wide 0.8mm thick complying with BS5057.

Combinations: Each terminal will accept either;

2 ring type connectors

or 2 push-on blade type connectors

or 1 ring type connector & 1 push-on blade type connector

1

3

5

7

9

11

13

15

17

19

21

23

25

27

2

4

6

8

10

12

14

16

18

20

22

24

26

28

Earth

Rear terminal block connections.

Each terminal

1 screw &

2 spade29

31

33

35

37

39

41

43

45

47

49

51

53

55

30

32

34

36

38

40

42

44

46

48

50

52

54

56

All information subject to change without notice

Publication number MRMF-Issue P


21/07/2010 Page 32 Issue P

10. Order Form

Digital Multifunctional Relay

MR

Mains Decoupling (Vector Surge) MF-1

Mains Decoupling (df/dt) MF-2

Voltage Relay VT

Frequency Relay FT

Generator/Mains Monitor OS

Rated Measurement Voltage, 100 V (110V) 1

230 V (240V) 2

400 V (415V) 4

Power Supply, 24V (16-60Vac, 16-80Vdc) L

110V (50-270Vac, 70-360Vdc) H

Housing, 19" Rack A

Flush Mounting D

PBSI Ltd Trading as

P&B ENGINEERING,

Belle Vue Works,

Boundary Street,

Manchester.

M12 5NG.

Tel: 0161-230-6363

Fax: 0161-230-6464

MRFT Issue 1 - Home - P&B -- P&B Assignment of the Output Relays for MRFT.....20 6.4 INDICATION OF...

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Transcript of MRFT Issue 1 - Home - P&B -- P&B Assignment of the Output Relays for MRFT.....20 6.4 INDICATION OF...