INDOOR BASIC FUNCTIONS

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INDOOR BASIC FUNCTIONS


OPERATING MODES

The system has 5 operating modes. The mode selection is done from indoor using handset.

The operating modes are:• Cool• Heat• Fan• Auto• Dry


COOL MODE

When Tr ≥ Ts - 1.5°C• Comp, ID Fan and OD Fan ON.

When Tr ≤ Ts - 2°C• Comp and OD Fan OFF.• ID Fan remain ON.

Tr = Room Temperature

Ts = Set Temperature


COOL MODE

When will Compressor Stop? When cooling load is too small, even with lowest

operation frequency and the room temperature still falling below compressor cut off point, compressor will stop.

Compressor Capacity

Time

Tr <= Ts - 2°CComp will stop

Lowest Freq


HEAT MODE

When Ts > Tr - 1.0°C• Comp, ID Fan and OD Fan ON.

When Tr ≥ Ts + 1.5°C• Comp and OD Fan OFF.• ID Fan remain ON at lowest speed if ID coil ≥ 27°C.

Tr = Room Temperature

Ts = Set Temperature


HEAT MODE

When will Compressor Stop? When heating load is too small, even with lowest

operation frequency and the room temperature still rising above compressor cut off point, compressor will stop.

Compressor Capacity

Time

Tr - Ts ≥ 1.5°CComp will stop

Lowest Freq


FAN MODE

Only High, Medium and Low fan speeds are allowed.

When changing cool mode to fan mode, the compressor will stop and OD fan stops based on fan OFF control.

Compressor will only ON if the minimum stop time is > 3 minutes and the user change back to cool mode.

Fan speed will maintain same as during fan mode.


AUTO MODE

For heat pump onlyMode switching point:

• Heating CoolingTr ≥ Ts + 2.5

• Cooling HeatingTr ≤ Ts – 2.5

During initial operation• Cooling operation: Tr > Ts• Heating operation: Tr < Ts


AUTO MODE – 5MSY Without Priority Room Setting

• When more than 1 indoor is operating, priority is given to the first unit that was turned on.

• If units that are turned on later to the same operating mode* as the first unit, all units will operate as normal.

• Otherwise, they will enter into Standby Mode.

With Priority Room Setting• Unit operation subjected to priority room operating

mode.

* - COOL, DRY and FAN mode may be used at the same time - AUTO mode automatically selects COOL mode or HEAT mode based on Tr. AUTO mode is available when selecting the same operation mode as that of the first room to be turned on.


ID-OD COMMUNICATION Master by outdoor unit. Indoor controller board will transmit signal to

outdoor controller board every 0.5s. Outdoor unit will response to indoor once the valid data is received.

Indoor

Outdoor

Send SignalSend SignalAcknowledgeAcknowledge


ID-OD COMMUNICATION

If the data communication line between indoor and outdoor disrupted for 15s continuously, compressor will stop, OD fan stop with fan OFF timer. ID LED blinks error.

If the communication resumes within 15s, error code is clear and compressor restarts after 3 minutes.

If the communication does not resume after 15s, unit unable to restart and the error keep blinking.


OUTDOOR BASIC FUNCTIONS


GENERAL FUNCTIONS


THERMISTORS

Thermistor 5LCY Series I 5LCY Series II 5MSY

Discharge pipe Outdoor coil Outdoor air Heat sink Suction pipe Gas pipe *Liquid pipe *

* Multiply by number of indoor.


THERMISTORS IN 5LCY Series I


THERMISTORS IN 5LCY Series IIOD heat exchanger thermistor

OD air thermistor

Discharge pipe thermistor

Suction pipe thermistor


THERMISTORS IN 5MSY

OD heat exchanger thermistor

Discharge pipe thermistor Gas pipe

thermistor

Liquid pipe thermistor


FUNCTIONS OF THERMISTOR Thermistor Functions

Discharge pipe Used for discharge superheat (SH) & EXV control. Also used for crankcase heater/ preheating control in 5LCY Series II.

Outdoor coil Used for defrost control. Also used for inverter current protection control in 5LCY Series II.

Outdoor air Used for defrost & outdoor fan speed control. Also used for PMV, overall current protection & preheating operation control.

Heat sink Used for capturing heat sink temperature.

Suction pipe Used for EXV (SH) & suction pipe SH protection control in heating.

Gas pipe Used for gas pipe isothermal control in cooling. EXV opening is controlled so that accurate cooling capacity is achieved in each room.

Liquid pipe Used for sub-cooling control in heating. Actual sub-cooling will be calculated with liquid pipe & max. heat exchanger temperature among all rooms. EXV opening is then adjusted to reach the target sub-cooling.


To prevent frequent compressor ON/OFF & toallow pressure equalization

• The compressor will be on 3 minutes stand-by after turning OFF before it is allowed to turn ON.

• OD fan OFF delay to improve pressure equalization & to prevent refrigerant from entering into evaporator.

MINIMUM RUN CONTROL

Applicable for the whole range


AUTO RESTART

Factory pre-set. Allow unit to automatically resume the same

operating mode it was in before a power failure.

Note:‒ Do not use as daily ON/OFF of the unit.‒ Make sure to turn OFF unit using handset first,

before turning OFF power supply to perform maintenance.



4-WAY VALVE CONTROL Change over switching is only carried out during operation. OFF delayed is applied when the coil switches from ON to

OFF, i.e. 5LCY Series I - 45 second, 5MSY – 150 second.

Operating mode 4-way valve isHeat, except for defrost ONCoolDryDefrost

OFF



DEFROST CYCLE

During defrost 5LCY Series I 5LCY Series II 5MSY

Compressor ON ON ON

4-way valve OFF

EXV in operation room Fixed opening

EXV in operation stop room - - Fixed opening*

Outdoor fan OFF OFF OFF

Indoor fan OFF



DEFROST CONTROLCondition for entering defrost

• Compressor minimum run time – 6 minutes OR• Compressor accumulated run time of 45 minutes

if OD coil < 3C.• When OD coil < 0C AND OD coil < OD air - 10C.

Condition for terminating defrost• OD coil > 12C or • Total defrost timer of 650 seconds.

Applicable for 5LCY Series I


DEFROST CONTROL Condition for entering defrost

• Compressor accumulated run time > 25 minutes since the completion of the previous defrost cycle AND

• Defrost timer A is met OR outdoor coil temperature is within the defrost request area.

OD air temperature A value

> -5 C 2 hours

-5 C 6 hours

Applicable for 5LCY Series II

Outdoor ambient, Ta (C)

Outdoor coil, Tb (C)

-20 -15 -10 -5 151050

Defrost request area

Defrost permit area

-1-3

-5-7

-9-11


DEFROST CONTROL


Condition for terminating defrost• Defrost time > 10 seconds when Hp > 24.5 bar or

• Defrost time > 60 seconds when Tb > 12C or

• Defrost time > 540 seconds when Tb > 10C or

• Total defrost time of 600 seconds is met.


DEFROST CONTROL Condition for entering defrost

• Compressor minimum run time – 6 minutes OR• Compressor accumulated run time > 38 minutes.• Based on OD coil temperature, output frequency &

OD air temperature.

Condition for terminating defrost• Minimum run time of 120 seconds, THEN• Determine based on OD ambient, in the range of 4C

≤ OD coil ≤ 12C OR • Total defrost timer of 650 seconds.

Applicable for 5MSY


OUTDOOR FAN CONTROL

This control is carried out according to:When compressor stops, fan OFF delay cut in

to expedite pressure equalization & to prevent refrigerant from entering in evaporator.

During defrost.During cooling/heating operation. In 5MSY, when no. of indoor decreases.



OUTDOOR FAN CONTROL Determine from

• Compressor target rotation: higher fan speed with higher rotation.

• Outdoor air temperature. Cool mode: Higher fan speed with higher

outdoor air temperature. Heat mode: Higher fan speed with lower

outdoor air temperature. When compressor stops, fan OFF delay 30

seconds is carried out



OUTDOOR FAN CONTROL

Control in the function of• Actual outdoor air temperature.• Condensation pressure.• Compression ratio: pressure difference

between low & high pressure.


Model No. of fan5LCY30ER Single5LCY40-60ER Twin


OUTDOOR FAN CONTROL

Step

Cooling Heating

5LCY30ER5LCY40-60ER

5LCY30ER5LCY40-60ER

M1F M2F M1F M2F

0 0 rpm 0 rpm 0 rpm 0 rpm 0 rpm 0 rpm











OUTDOOR FAN CONTROL

When compressor stops, fan OFF delay 60 seconds is carried out.

When no. of heating room decreases, fan OFF delay 30 seconds applied if outdoor ambient > 10C.

Applicable for 5MSY


PMV CONTROL Factory pre-set to be ON. Only active in auto mode. Minimize excessive cooling and heating based on the

predicted mean values (PMV) index specified in ISO7730 reduces annual power consumption without affecting the overall room comfort.

The set point will be moved 1 or 2 C, depending on the actual ID & OD temp. & actual set point, subject to condition changes. The PMV value is calculated every 5 seconds.



PREHEATING OPERATION CONTROL

Model: 5LCY30ER Activate after compressor has cut out to avoid refrigerant from

dissolving into the compressor oil. Entering condition:

• Compressor stops AND • Power ON for < 6 hours OR > 1 hour after compressor stops, OD

ambient temp. is not decreasing & discharge pipe temp. < 70C. Ending condition:

• Thermostat cut in AND• Power ON for > 6 hours OR < 1 hour after compressor stops,

ambient temp. is not decreasing & discharge pipe temp. > 75C.



PREHEATING OPERATION CONTROL

Model: 5MSY Entering condition:

• OD ambient < 10.5C AND• Discharge pipe temp. < 10.5C.

Ending condition:• OD ambient > 12C AND• Discharge pipe temp. < 12C

Applicable for 5MSY


CRANKCASE HEATER CONTROL

Model: 5LCY40-60ER Activate after compressor has cut out to avoid

refrigerant from dissolving into the compressor oil.

70 C 75 C

ON

OFF

Discharge pipe temperature



INDOOR COIL FREEZE PREVENTION

Only available in cooling mode. When the indoor coil temperature < 2°C, the

compressor starts to drop the frequency. This protection will cut in when:

• Indoor coil temperature < 0°C for more than 180s. Compressor will stop, OD fan stop after 30s and indoor fan can only run at lowest fan speed.

The unit can only be restarted after 3 minutes. When the indoor coil temperature > 13°C, the

compressor frequency will be reset based on the OD ambient, room and set temperature.



ROTATION REGULATINGFUNCTIONS


OVERVIEW

Command Rotation

Starting RotationT

Defrost*

Limit Rotation

Lower limit rotation

Upper limit rotation

Target Rotation

* Defrost control for heat pump model only


STARTING ROTATION


STARTING CONTROL

To avoid excessive oil discharge from compressor or to promote oil lubrication during startup.

To prevent liquid flood back to the compressor. To limit starting current. When compressor starts to rotate from OFF to

ON, compressor rotation is set to run gradually to each upper limit at a specific timer setting.


STARTING CONTROL


Compressorrotation, f

Time (min)1 2 6

Model Max. f

5LCY10DR 68 Hz

5LCY15DR 74 Hz

5LCY20CR 90 Hz

5LCY25CR 93 Hz

20

35

55

Max


STARTING CONTROL Normal starting control time is 2-3 minutes & is

limited to maximum of 10 minutes.

Model A

5LCY30ER 79 Hz

5LCY40-60ER 112 Hz

Time (min)2-31

Step 1

A

Hz


Terminating when low pressure < 6 bar OR when the maximum starting time of 10 minutes has been reached if low pressure stays > 6 bar.


STARTING CONTROL

Compressorrotation, R

Time (seconds)T1 T2 T3

R1

R2

R3

Applicable for 5MSY

5MSY20BR 5MSY25/30BR

R3 85 80

R2 70 65

R1 55 55

T1 150 120

T2 180 200

T3 300 470


COMMAND ROTATION


COMMAND ROTATIONCut in upon termination of Starting Control.Achieve capacity control by controlling the

compressor rotation based on :• Temperature difference between set and room

temperature, T.• Limit Rotation.• Defrost control.


COMMAND ROTATION

Temperature DifferenceTemperature Difference

Tt = Troom - TsetTt = Troom - Tset

Compressor frequency is increased or decreased

Compressor frequency is increased or decreased

Condition 1 T

Condition 1 T

Condition 2 dT

Condition 2 dT

dT = Tt – Tt-1dT = Tt – Tt-1

Use to set target for compressor frequency change Use to set target for compressor frequency change

Fuzzy Control Based on temperature difference, T, current fan speed setting

& current indoor operating mode at every 30 seconds interval.



COMMAND ROTATION Compressor frequency is controlled to ensure a constant evaporation

temperature in cooling and condensing temperature in heating.

In cooling, target rotation is determined by T& evaporating temperature, Te. T cool = set temperature – room temperature

• Depending on the cooling load, 2C Target Te 20C

In heating, target rotation is determined by T& condensing temperature, Tc. T cool = room temperature – set temperature

• Depending on the heating load, 42C Target Tc 54C

Frequency changes at every 20 seconds, maximum at 2 steps/change (6 steps/min)

During abnormal condition, frequency changes at 2 steps but may be at < 20 seconds interval.



COMMAND ROTATION The operating frequency will be chosen from a list of fixed frequency

settings programmed in the unit’s memory:


Step no.

5LCY30ER 5LCY40-60ER

(Hz)

1 48.0 32

2 52.5 36

3 57.0 41

4 61.5 44

5 66.0 48

6 72.0 52

7 78.0 57

8 85.5 62

9 93.0 67

Step no.


(Hz)

10 100.5 72

11 109.5 78

12 118.5 84

13 127.5 90

14 136.5 94

15 145.5 98

16 154.5 102

17 163.5 107

18 174.0 112

Step no.


(Hz)

19 183.0 117

20 192.0 123

21 201.0 131

22 211.5 139

23 222.0 147

24 232.5 155

25 243.0 164

26 253.5 -

27 265.5 -: Max. frequency in cooling


COMMAND ROTATION

PI CONTROL Based on P control, I control & S value. P control: T of each indoor is calculated at every sampling

time of 20s and compressor rotation is adjusted according to the difference from the previously calculated rotation.

I control: if the operating frequency is not changed more than a certain fixed time, a total value of T (T) is obtained:• If T is small lower frequency.• If T is large increase frequency.

Applicable for 5MSY


COMMAND ROTATION S value:

• Indoor unit capacity value which is used for frequency command.

• Total S value of each room is used to determine the upper and lower frequency limits.

Indoor capacity S value

1.0 hp 25

1.5 hp 35

2.0 hp 50

2.5 hp 60

Applicable for 5MSY


LIMIT ROTATION


LIMIT ROTATION

Determine from• Upper limit rotation

A minimum value is determine among the upper limits rotation, i.e. protection controls.

• Lower limit rotationA maximum value is determine among the lower limits

rotation, i.e. protection controls.


OVERVIEWGenerally, compressor rotation is controlled within 4 zones: stop, drop, keep, up and reset subjected to a particular operating temperature/current/pressure.

Zone Control

Stop Compressor is stopped when a certain limit reaches the stop zone for abnormality correction.

Drop Frequency will be dropped with a timer setting.

Keep Frequency is maintained at lower/upper limit.

Up Frequency will be increased with a timer setting.

Reset Frequency lower/upper limit is canceled and returned to command rotation.


LOW PRESSURE PROTECTION To prevent abnormal low pressure in the system. Detected by low pressure sensor.


Mode Activation Compressor stop Reset

5LCY30ER

Cooling LP < 1.2bar LP < 1.2bar & after 5 min elapsed

LP > 1.5bar & 30 sec elapsed OR 10 times stopping in 200 min

Heating

LP < 1.2bar ANDWithin 10 min after defrost OR LPS activates continuously for 5 min

LP < 1.2bar & after 5 min elapsed

LP > 1.5bar & 60 sec elapsed OR 10 times stopping in 200 min

5LCY40-60ER

Cooling LP < 4.9bar LP < 0.5bar OR LP < 1bar for 5 min

LP > 5.9bar & after 30 second elapsed OR 10 times stopping in 200 min

Heating

LP < 1.5bar ANDWithin 5 min after startup OR within 10 min after defrost OR *

*Within 10 min after defrost & LP < 1bar 5 min continuous & LP < 0.5bar

10 times stopping in 200 min


HIGH PRESSURE PROTECTION

To prevent high pressure in the system.Compressor operating frequency is adjusted

based on upper limit of coil temperature (5SLY series I & 5MSY) or system pressure (5LCY series II).




The compressor frequency is adjusted based on coil temperature:• During cooling mode – outdoor coil temperature.• During heating mode – indoor coil temperature.

This protection is activated when the coil temperature > 64°C, the compressor stop and OD fan stop after 30s.

The unit can only be restarted after 3 minutes.





> D: compressor rotation set to AI

F

G

Reset zone

Frequency drop zone

Stop zone

CD

H+ 1 step/5 min

+ 1 step/min

A C D F G H I

5LCY30ER 118.5 Hz 32.2 bar 33.2 bar 31.8 bar 29.4 bar 30.8 bar 39.2 bar

5LCY40-60ER 62 Hz 36.8 bar 37.7 bar 36.3 bar 34.3 bar 35.8 bar 39.2 bar

During cooling operation

> 1 min or HPS activates

Up zone




> D: compressor rotation set to B

I

32.4 bar

Reset zone

Stop zone

C

B C I

5LCY30ER 118.5 Hz 32.2 bar 39.2 bar

5LCY40-60ER 62 Hz 36.8 bar 39.2 bar

During heating operation

OR HPS activates

30 seconds elapsed



The compressor rotation is adjusted based on calculated high pressure (HP) value from the low pressure, power input & compressor frequency.

This protection is activated when HP > C. HP switch (HPS) will be activated or HP > I (cooling for 1 min) compressor stops.

• HP switch opens at 40 bar (tolerance +0/-0.15)• HP switch closes at 30 bar (tolerance +/-0.15)

Error code indication (E3) will cut in when compressor stops 16 (cooling) /15 (heating) times in 300 min.




60C

59C

56C

Reset zone

Drop zone

Remain zone

Applicable for 5MSY

Based on coil temperature:• During cooling mode – outdoor coil temperature.• During heating mode – indoor coil temperature.

This protection is activated when coil temperature among the operating rooms > 60°C.

The system stops after staying in the frequency reduce zone for 2 minutes.


Used as a measure of the compressor’s internal temperature.

Compressor frequency is control to keep this temperature from going up further when it rises above a certain level.

DISCHARGE PIPE TEMPERATURE CONTROL




(120C)

(111C)

(109C)

(107C)

Note: 5LCY (5MSY)

Applicable for 5LCY Series I & 5MSY

Stop zone

Drop zone

Frequency keep zone

Reset zone

Discharge temperature


If compressor discharge temperature >102°C (111°C) for the first time, this control starts and set the current frequency as upper limit. At the same time, running frequency start to reduce by 1 step and so on, until temperature falls between 99°C (109°C)and 90°C (107°C) – at the maintain zone.

This protection is activated when the compressor discharge temperature > 110°C (120°C). The compressor will stop and considered trip.

If the compressor discharge temperature < 90°C (107°C), the compressor frequency will be reset based on the OD ambient, set and room temperature.






Normal operation

- 1 step/20 second

Set to H Hz

Compressor stop

Td > BC

Td CC 5 min continuous & 300 second elapsed

OR Td > DC

Td EC G min continuous

OR Td FC

+ 1 step/60 second Td BC

10 times in 200 min

Td < AC OR

Td B C & 5 min elapsed

Td < AC OR

Td < BC & Upper limit f = max f

A B C D E F G H

5LCY30ER 100C 105C 110C 120C 110C 125C 15min 118.5Hz

5LCY40-60ER 100C 105C 110C 120C 115C 135C 10min 62Hz


OVERALL CURRENT CONTROL

To monitor the overall current and to restrict the compressor upper limit rotation in order to prevent circuit breakers from exceeding the rated capacity.

Detected during compressor running.




Current (A)

L1

L2

L3

Stop zone

Frequency reduce zone

Frequency remain zone

Reset zone

Model L1

5LCY10DR 9.5A

5LCY15DR 10.0A

5LCY20CR 12.0A

5LCY25CR 12.0A

5MSY20BR 20.0A

5MSY25BR 19.5A

5MSY30BR 19.5A



OVERALL CURRENT CONTROL When the input current for running compressor

exceeds L2, running frequency will be reduced by 1 step. If current still exceeds L2, frequency will be reduced by another 1 step until total current falls between L2 and L3.

This protection cut in when the input current exceeds L1 for 2 seconds – 5LCY series I or 2.5 seconds – 5MSY. Compressor will stop and it is considered total current overload.

If input current <L3, the compressor frequency is reset based on the OD ambient, set and room temperature.




Upper Limit Current (A)

D

C

B

U

25 28 43 50 OD air temperature

A 5LCY30ER 5LCY40-60ER

U 16.5 24.0

B 16.5 24.0

C 13.4 23.0

D 10.0 16.0

To monitor overall current and restrict the compressor upper limit (CULR) rotation to prevent circuit breakers from exceeding the rated capacity.

Normal operation

f -1 step/10s f +1 step/120sOD unit current < A

OD unit current > A

- OD unit current A AND f = max. rotation OD unit current

> A



OIL RECOVERY CONTROL

When the compressor operates for a certain duration at low frequency, the oil level in the compressor may become low due to incomplete oil return.

To prevent damage to the compressor or compressor lock due to low oil lever.

To promote refrigerant flow to carry the oil back to the compressor.




Entering condition:• Compressor rotation < 35 Hz, at the end of a 20

minutes timer: set lower limit rotation to 35 Hz & EXV opening is fixed at current opening + 50 pulse. This control is reset when rotation > 35 Hz.

OR• Compressor rotation > 35 Hz, for every 120

minutes: current rotation is remained & EXV is fixed at current opening + 50 pulse. This control is reset after 5 minutes.




This operation only cut in during cooling mode, compressor frequency will be increased to a certain level for a duration of 5 minute.

Enter condition: f 63Hz for 5 minute continuously and system will calculate the oil discharge amount.

During heating mode, oil return is guaranteed by the defrost operation.




When one of the cooling room stops, the EXV opening will be set to open for a certain time at a specified interval so that the oil may not accumulate in the cooling stopped room.

During cooling operation, for every 1 hour of continuous operation, the EXV in the operation stopped room will be set to opened for 80 pulses for a specified time.

Applicable for 5MSY


THANK YOU&

Q & A

INDOOR BASIC FUNCTIONS

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