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THREE PHASE OVER CURRENT +

EARTH FAULT RELAY WITH HIGHSET

TYPE MC61ARelay MC61A is a three phase over current + Earth fault relay with 4 measuring elements.

The relay has built in highest (instantaneous trip) protection, for both over current & earthfault elements. The relay can be used for feeder protection in all low voltage, medium voltage

and high voltage sub-stations. The relay has a front panel 4 digit seven segment LED display

to read various settings, on line values, switch on values, last trip data etc. User has a choice

of 7 trip time characteristics.

TECHNICAL SPECIFICATIONS

1.0 Rated Current In 1A or 5A (Field selectable)

2.0 Rated Frequency 50Hz 2.5 Hz

3.0 Auxiliary Power Supply 24V to 110V AC/DC 15% or

95V to 240V AC/DC 15%4.0 Relay Settings:

Over Current (Is) 0.2 to 2.0 times In, in steps of 0.05In

High set Over Current (Ihs) 0.2 to 40 times In, in steps of 0.2 Inor Disable

Earth Fault (Os) 0.05 to 0.8 times Onin steps of 0.05 On

High set Earth fault (Ohs) 0.1 to 20 times Onin steps of 0.1 Onor Disable

Time Multiplier 0.1 to 1.6 in steps of 0.05 (independent settings for O/C

& E/F modes)

5.0 Operating Characteristics Front panel programmable, using push buttons.

Time /Current Separate characteristics can be selected for O/C &

Characteristics E/F modes.

a) Normal Inverse (NI) 3sb) Normal Inverse (NI) 1.3s

c) Very Inverse (VI)

d) Extremely Inverse (EI)

e) Definite Time (DT) 1s

f) Definite time (DT) 10s

g) Definite time (DT) 100s

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Three Phase Over current

Earth Fault

Highset Over current

Higset earth fault

Inverse & Definite time trip Characteristics4 digit display

CT secondary 1A / 5a field selectable

50 / 51, 50N/ 51N

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High set operating time Less than 50 millisecond at 2 Ihs

Accuracy As per Error class 5 of IS: 3231: 1987

Pick up current Same as set current

Reset Current 95% to 90% of pick up current

Reset time 0.1 to 10sec in steps of 0.1 sec or less than 50 ms

6.0 Burden Less than 0.25 VA/ phase at CT inputs

Less than 10 VA at Auxiliary Power supply

7.0 Operation Indicators Separate LED indications for:

Power on

Trip status for R, Y, B & E

(These LEDs blink when input crosses set point and

become steady on when relay has tripped. LEDs

have to be manually reset)

4 digits, seven segment LEDs for parameter display

8.0 Output Relay Contacts 4 contacts for trip signal on feeder faults

(One version with 2N/O + 2 N/C and

Other version with 4 N/O).

1 N/C contact for internal relay fault9.0 Output contact rating

Rated voltage 250 V AC / 30 V DC

Rated current 5A

Rated Breaking Capacity 2000VA / 240 W (Resistive)

10.0 Over Load capacity 2 times rated current continuously

20 times rated current for 1 sec

11.0 Electrical performance Please refer separate document

Specifications General Electrical Characteristics

12.0 Case

Front Bezel 158 x 136 mm

Panel Cutout 142 x 113 mm

Depth 204 mm13.0 Weight 1.5 kG approx.

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CATALOG NOs.

MC61AAXX000

MC61AAXX001

MC61ABXX000

MC61ABXX001

ORDERING INFORMATION :

1) Auxiliary Power supply Type A or Type B

2) Contact configuration 4 N/O or 2 N/0 + 2 N/C

6 1 A AC X XM 0 0 0

Contact Configuration

0 = 4 N/O

1 = 2 N/O + 2 N/C

Aux. Power supply

A = 24 to 110 V AC/DC 10%

B = 110 to 240 V AC/DC 10%