Mitsubishi Electric PLH Series Operating manual

TECHNICAL & SERVICE MANUAL
SPLIT-TYPE,HEAT PUMP AIR CONDITIONERS
CONTENTS
1. FEATURES ···········································3
2. PART NAMES AND FUNCTIONS········5
3. SPECIFICATIONS·································7
4. DATA ···················································11
5. OUTLINES AND DIMENSIONS··········15
6. WIRING DIAGRAM·····························18
7. REFRIGERANT SYSTEM DIAGRAM ······19
8. OPERATION FLOW-CHART··············20
9. MICROPROCESSOR CONTROL·······24
10. TROUBLESHOOTING························47
11. 4-WAY AIR FLOW SYSTEM···············55
12. SYSTEM CONTROL···························60
13. DISASSEMBLY PROCEDURE···········65
14. PARTS LIST········································68
15. OPTIONAL PARTS·····························78
[Model names]
PLH-3GK(H)B
PLH-4GK(H)SB
PLH-5GK(H)SB
PLH-6GK(H)SB
No. OC148
1997
This manual does not cover the following
outdoor units. When servicing them,
please refer to the service manual
No.OC150 and this manual in a set.
[Service Ref.]
PUH-3YKA2.UK
PUH-3VKA2.UK
PUH-4YKSA2.UK
PUH-5YKSA2.UK
PUH-6YKSA2.UK
INDOOR UNIT
Ceiling Cassettes
Series PLH
FILTER
CHECK MODE
TEST RUN
REMOTE CONTROLLER The Slim Line.
From Mitsubishi Electric.
[Service Ref.]
PLH-3GK(H)B 1 .UK
PLH-4GK(H)SB
1 .UK
PLH-5GK(H)SB
1 .UK
PLH-6GK(H)SB
1 .UK

3
FEATURES
1
1.THE QUIETEST PERFORMANCE IN THE FIELD-39 PHONS(PLH-3GK(H)B.UK)
Excellent noise suppression is achieved because of the turbofan’s large diameter. Also wing-shaped vanes and a low-resis-
tance air flow desigh help to suppress noise.
2.FAN CONTROL ELIMINATES SUDDEN,SHARP NOISES
Sudden,sharp noises are eliminated by a fan control mechanism that smoothly and gradually increases rpms when the ther-
mostat switches the heater on or when the air conditioners in the dehumidifying“dry”mode.
3.VERSATILE AIR FLOW
Fan phase control and computer control allow a wide variety of air flow configurations. The optimal blown-air volume can be
chosen in accordance with the ceilling height and number of air vents at specific settings.
4.AUTOMATIC SETTING OF THE OPTIMAL AIR OUTLET ANGLE
The air outlet angle is altered automatically,to an almost horizontal angle of 20˚during cooling and an almost perpendicular
angle of 65˚during heating,to deliver the most comfort possible.This mechanism gives an even greater control over air flow.
5.NEXT-GENERATION AIR -CONDITIONING VENTILATION INTERLOCK SYSTEM
“Mr.SLIM” + “LOSSNAY”
Proper ventilation is important to improve the quality of indoor environments. lt eliminates unclean air,which is not only
unpleasant,but also unhealthy.
The“Mr.SLM”+“LOSSNAY”ventilation interlocking system achieves high air quality with minimum energy consumption.
LOSSNAY´s unique total heat exchanger reduces heating and cooling expenses by about 25 percent annually(in compari-
son with our exisiting models). ln addition,its mechanism of simultaneous forced air supply and exhaust enables it to deliver
high quality air.
Together the“Mr.SLIM”+“LOSSNAY”system makes next-generation air conditioning possible. This system is both people-and
environmental-friendly.
6.FLUCTUATING AIR CONTROL THAT ELIMINATES DRAFTS
A computerized fluctuating air control mechanism automatically controls the flow of air so that it feels natural and free of
drafts. Linkage with a swing mechanism sends a refreshing and natural breeze throughout the room. <Cooling><Air flow>
Indoor unit
Ceiling Cassettes
Series PLH
Remote controller
FILTER
CHECK MODE
TEST RUN
Service Ref.
PLH-3GK(H)B1.UK
PLH-4GK(H)SB1.UK
PLH-5GK(H)SB1.UK
PLH-6GK(H)SB1.UK
Cooling capacity/Heating capacity
Btu/h
26,300/28,700[35,800]
33,100/35,500[44,400]
42,300/45,700[56,000]
46,100/54,300[64,500]
W
7,700/ 8,400[10,500]
9,700/10,400[13,000]
12,400/13,400[16,400]
13,500/15,900[18,900]

4
7.INCREASED DEHUMIDIFICATION WITH FAN PHASE CONTROL NEW ELECTRONIC
DEHUMIDI-FIER OPERATION
A new electronic dehumidifier mode,where fan speed is controlled precisely by fan phase control,increases dehumidification
volume and raises dehumidifying effectiveness.This results in a pleasant environment all-year around,even during extended
rainy seasons.
8. A90˚GRILL SWITCHING MECHANISM MAKES INSTALLATION CONSIDERABLY EASIER (3HP)
The direction of the panel designs can be adjusted to match the interior desigh of the space in which tyey are being used.
This allows for greater flexibillty in air conditioning space and plumbing work.
9.HIGH-PERFORMANCE FILTER(colorimetric method:65%)OPTION
A high-performance filter can be installed(colorimetric method:65%)by setting the blown-air volume switch SWC.
10 .OUTSIDE AIR INCORPORATION
lnstallation of an outside air intake casement(option)allows fresh air
from outside to be incorporated with limited pressure loss.
11 .ADVANCED MICROPROCESSOR
(1)Easy to use microprocessor
1)Ultra-thin remote controller
The streamlinde,square controller is designed to blend well with
any interior.Also,the sophisticated microproceeor allows you to
easily carry out a wide range of operations.
2)Attractive liquid crystal display(LCD)
The unit´s operation mode,set temperature,room
temperature,timer setting,fan speed,louver oper-ation,and air flow
direction are displayed on the remote controller´s easy-to-read
Liquid Crystal Dis-play(LCD).
3)Convenient 24-hour ON-OFF timer
The timer switches Mr.SLIM on and off automati-cally at the time
you set. Once the timer is set,the remaining time is shown on the
LCD.
12 .INNOVATIVE SYSTEM CONTROL BY MICROPROCESSORS
The most significant feature of the series PLH-GK(H)(S)B is the advanced microprocessor control. The development of this
system is due to the recent world-wide trend in the air conditioning of larger buildings. They are moving away from central-
ized duct systems and using individual split type units instead. There are a number of reasons for this change. First of
all,the duct´s costly,and troublesome installation is eliminated. Second,the overall air conditioning balance is excellent in
split type units. Lastly,the operation costs are low due to the flexible control of each unit. This system was developed exclu-
sively by Mitsubishi Electric because of high demand. The microprocessor control makes individual control,group
control,control using two remote controllers,and remote on/off and individual control possible without trouble-some equip-
ment modifications.
FILTER
CHECK MODE
TEST RUN

5
PART NAMES AND FUNCTIONS
2
● Indoor (Main) Unit
On the controls are set, the same operation mode can be repeated by simply pressing the ON/OFF button.
Auto Air Swing Vane
Disperses airflow up and
down and adjusts the angle
of airflow direction.
Grill
Filters
Remove dust and pollutants
from inihaled air
Horizontal Air Outlet
Sets airflow horizontal automatically
during cooling or dehumidifying.
Downward Air Outlet
Sets airflow downward
automatically during
heating.
Air Intake
Inhales air from room.
FILTER
CHECK MODE
TEST RUN
● Operation buttons
● Remote controller
CHECK-TEST RUN button
Only press this button to per-
form an inspection check or test
operation Do not use it for
nomal operation.
(This button does not operate in this
model)
button
This switches the horizontal fan
motion ON and OFF.
FILTER button
This resets the filter service indica-
tion display.
ON/OFF button
This switches between the operation
and stop modes each time it is
pressed. The lamp on this butoon
lights during operation.
button
This adjusts the vertical angle of the
ventilation.
button
This sets the ventilation fan
speed.
button
This sets of switches the current
time. start time and stop time.
button
This switches between continuous
operation and the timer operation.
TEMP button
This sets the room temparature The
temparature setting can be per-
formed in 1°C units
Setting range
Cooler 19°C to 30°C
Heater 17°C to 28°C
button
Press this button to switch the cooler
electronic dry (dehumidify) automatic
and heater modes.
This model name of the remote con-
troller is indicated.

6
Caution
●Only the display lights when the unit is stopped and power supplied to the unit.
●When power is turned ON for the first time the (CENTRAL CTRL) display appears to go off momentarily but this is not a
malfunction.
●When the central control remote control unit, which is sold separately, is used the ON-OFF button, button and
TEMP button do not operate.
●“NOT AVAILABLE” is displayed when the button are pressed.This indicates that this room unit is not equipped with
the fan direction adjustment function and the louver function.
FILTER
CHECK MODE
TEST RUN
Operation lamp
This lamp lights during operation,
goes off when the unit stops and
flashes when amalfunction occurs.
CENTRALLY
CONTROLLED display
This indicates when the unit is con-
trolled by optional features such as
central control type remote controller.
display
This indicates when the continous
operation and time operation modes
are set.
It also display the time for the timer
operation at the same time as when
it is set.
OPERATION MODE display
This indicates the operation mode.
STANDBY display
This indicates when the standby
mode is set from the time the sleep
operation starts until the heating air
is discharged.
DEFROST display
This indicates when the defrost oper-
ation is performed.
CHECK display
This indicates when a malfunction
has occurred in the unit which should
be checked.
display
This lamp lights when electricity is
supplied to the unit.
display
This displays the selected setting
temperature.
display
The current time , start time and stop
time can be displayed in tensecond
intervals by pressing the time switch
button. The start time or stop time is
always displayed during the timer
operation.
display
The selected fan speed is displayed.
●Display
display
The temperature of the suction air is
displayed during operation. The dis-
play range is 8° to 39°C. The display
flashes 8°C when the actual temper-
ature is less than 8° and flashes
39°C when the actual temperature is
greater than 39°C.
In this display example on the bot-
tom left, a condition where all dis-
play lamps light is shown for expla-
nation purposes although this differs
from actual operation.
display
This display lights in the check mode
or when a test operation is per-
formed.
CHECK MODE
TEST RUN
display
This lamp lights when the filter need
to be cleaned.
FILTER
display
This displays the air
direction.

7
SPECIFICATIONS
3
Service Ref.
Power supply(phase, cycle,voltage)
External finish
Heat exchanger
Booster heater
Operation control & Thermostat
Noise level(Low-High)
Cond. drain conn. O.D.
Dimensions
Weight
Service Ref.
Power supply (phase, cycle, voltage)
External finish
Refrigerant control
Compressor
Heat exchanger
Defrost method
Noise level
Dimensions
Weight
Refrigerant
Pipe size O.D.
Connection method
Between the indoor & outdoor units
Input
Running current
Starting current
Fan(drive) x No.
Fan motor output
Airflow(Low-High)
External static pressure
Input
Running current
Starting current
Model
Motor output
Starter type
Protection devices
Fan(drive) x No.
Fan motor output
Airflow
Charge
W
D
H
W
D
H
Liquid
Gas
Indoor side
Outdoor side
Height difference
Piping length
Function
Capacity
Total input
INDOOR UNITOUTDOOR UNIT
REFRIGERANT
PIPING
Item Service Ref.
Btu/h
W
kW
kW
A
A
kW
K/ min (CFM)
Pa(mmAq)
kW
dB(A)
mm,(in)
mm,(in)
mm,(in)
mm,(in)
kg,(lbs)
kW
A
A
kW
kW
K/ min (CFM)
dB(A)
mm,(in)
mm,(in)
mm,(in)
kg,(lbs)
kg,(lbs)
mm,(in)
mm,(in)
PLH-3GK(H)B.UK
Cooling
26,300
7,700
3.31
Heating
28,700[35,800]
8,400[10,500]
3.10[5.20]
0.16
0.72
1.00
0.16[2.26]
0.72[9.5]
1.00[9.8]
UNIT : 820(32-1/4)
UNIT : 820(32-1/4)
UNIT : 258(10-1/8)
UNIT : 29(64)
PANEL : 950(37-3/8)
PANEL : 950(37-3/8)
PANEL : 65(2-9/16)
PANEL : 7(16)
3.15
13.82/5.16
58/37
2.94
12.89/4.81
58/37
PLH-3GK(H)B1.UK
Single, 50Hz, 220-240V
Galvanized sheets with gray heat insulation
Plate fin coil
Turbo fan (direct) x 1
0.050
14-18(495-640)
0(direct blow)
[2.1]
Remote controller & built-in
32-39
30(1-1/4)
PUH-3VKA2.UK/PUH-3YKA2.UK
Single, 50Hz, 220-240V/3, 50Hz, 380-415V(4wires)
Munsell 5Y 7/1
Capillary tube
Hermetic
NH52VND/NH52YDA
2.2/2.4
Line start
w1
Plate fin coil
Propeller (direct) x1
0.085
50(1764)
Reverse cycle
52
870(34-1/4)
295+24 (11-5/8 add 1)
850(33-1/4)
75(165)
R-22
3.2(7.1)
9.52 (3/8)
15.88(5/8)
Flared
Flared
Max. 50m
Max. 50m
wV …Internal Thermostat, HP switch
Y…Anti-phase protector, thermal relay, thermal switch, HP switch

8
Service Ref.
Power supply(phase, cycle,voltage)
External finish
Heat exchanger
Booster heater
Operation control & Thermostat
Noise level(Low-High)
Cond. drain conn. O.D.
Dimensions
Weight
Service Ref.
Power supply (phase, cycle, voltage)
External finish
Refrigerant control
Compressor
Heat exchanger
Defrost method
Noise level
Dimensions
Weight
Refrigerant
Pipe size O.D.
Connection method
Between the indoor & outdoor units
Input
Running current
Starting current
Fan(drive) x No.
Fan motor output
Airflow(Low-High)
External static pressure
Input
Running current
Starting current
Model
Motor output
Starter type
Protection devices
Fan(drive) x No.
Fan motor output
Airflow
Charge
W
D
H
W
D
H
Liquid
Gas
Indoor side
Outdoor side
Height difference
Piping length
Function
Capacity
Total input
INDOOR UNITOUTDOOR UNIT
REFRIGERANT
PIPING
Item Service Ref.
Btu/h
W
kW
kW
A
A
kW
K/ min (CFM)
Pa(mmAq)
kW
dB(A)
mm,(in)
mm,(in)
mm,(in)
mm,(in)
kg,(lbs)
kW
A
A
kW
kW
K/ min (CFM)
dB(A)
mm,(in)
mm,(in)
mm,(in)
kg,(lbs)
kg,(lbs)
mm,(in)
mm,(in)
PLH-4GK(H)SB1.UK
Cooling
33,100
9,700
3.46
Heating
35,500[44,400]
10,400[13,000]
3.45[6.05]
0.26
1.18
1.50
0.26[2.86]
1.18[12.0]
1.50[12.3]
UNIT : 1340(52-3/4)
UNIT : 820(32-1/4)
UNIT : 258(10-1/8)
UNIT : 45(99)
PANEL : 1470(57-7/8)
PANEL : 950(37-3/8)
PANEL : 65(2-9/16)
PANEL :10(22)
3.20
5.24
40
3.19
5.22
40
PLH-4GK(H)SB1.UK
Single, 50Hz, 220-240V
Galvanized sheets with gray heat insulation
Plate fin coil
Turbo fan (direct) x 2
0.050+0.050
23-32(810-1130)
0(direct blow)
[2.6]
Remote controller & built-in
34-42
30(1-1/4)
PUH-4YKSA2.UK
3, 50Hz, 380-415V(4wire)
Munsell 5Y 7/1
Capillary tube
Hermetic
NH56YDA
2.7
Line start
Anti-phasa protector, Thermal relay, Thermal switch, HP switch
Plate fin coil
Propeller (direct) x2
0.065+0.065
95(3550)
Reverse cycle
54
870(34-1/4)
295+24(11-5/8 add 1)
1258(49-1/2)
94(207)
R-22
4.2(9.2)
9.52(3/8)
19.05(3/4)
Flared
Flared
Max. 50m
Max. 50m

9
Service Ref.
Power supply(phase, cycle,voltage)
External finish
Heat exchanger
Booster heater
Operation control & Thermostat
Noise level(Low-High)
Cond. drain conn. O.D.
Dimensions
Weight
Service Ref.
Power supply (phase, cycle, voltage)
External finish
Refrigerant control
Compressor
Heat exchanger
Defrost method
Noise level
Dimensions
Weight
Refrigerant
Pipe size O.D.
Connection method
Between the indoor & outdoor units
Input
Running current
Starting current
Fan(drive) x No.
Fan motor output
Airflow(Low-High)
External static pressure
Input
Running current
Starting current
Model
Motor output
Starter type
Protection devices
Fan(drive) x No.
Fan motor output
Airflow
Charge
W
D
H
W
D
H
Liquid
Gas
Indoor side
Outdoor side
Height difference
Piping length
Function
Capacity
Total input
INDOOR UNITOUTDOOR UNIT
REFRIGERANT
PIPING
Item Service Ref.
Btu/h
W
kW
kW
A
A
kW
K/ min (CFM)
Pa(mmAq)
kW
dB(A)
mm,(in)
mm,(in)
mm,(in)
mm,(in)
kg,(lbs)
kW
A
A
kW
kW
K/ min (CFM)
dB(A)
mm,(in)
mm,(in)
mm,(in)
kg,(lbs)
kg,(lbs)
mm,(in)
mm,(in)
PLH-5GK(H)SB1.UK
Cooling
42,300
12,400
4.49
Heating
45,700[56,000]
13,400[16,400]
4.44[7.44]
0.28
1.27
1.50
0.28[3.28]
1.27[13.8]
1.50[14.0]
UNIT : 1340(52-3/4)
UNIT : 820(32-1/4)
UNIT : 258(10-1/8)
UNIT : 45(99)
PANEL : 1470(57-7/8)
PANEL : 950(37-3/8)
PANEL : 65(2-9/16)
PANEL :10(22)
4.21
6.89
53
4.16
6.81
53
PLH-5GK(H)SB1.UK
Single, 50Hz, 220-240V
Galvanized sheets with gray heat insulation
Plate fin coil
Turbo fan (direct) x 2
0.050+0.050
24-33(850-1165)
0(direct blow)
[3.0]
Remote controller & built-in
36-43
30(1-1/4)
PUH-5YKSA2.UK
3, 50Hz, 380-415V(4wire)
Munsell 5Y 7/1
Capillary tube
Hermetic
ZR61K3-TFD
3.5
Line start
Internal thermostat, Anti-phasa protector, Thermal switch, HP switch
Plate fin coil
Propeller (direct) x2
0.085+0.085
95(3550)
Reverse cycle
55
970(38-3/16)
345+24(13-9/16 add 1)
1258(49-1/2)
114(251)
R-22
5.4(11.9)
9.52(3/8)
19.05(3/4)
Flared
Flared
Max. 50m
Max. 50m

10
Service Ref.
Power supply(phase, cycle,voltage)
External finish
Heat exchanger
Booster heater
Operation control & Thermostat
Noise level(Low-High)
Cond. drain conn. O.D.
Dimensions
Weight
Service Ref.
Power supply (phase, cycle, voltage)
External finish
Refrigerant control
Compressor
Heat exchanger
Defrost method
Noise level
Dimensions
Weight
Refrigerant
Pipe size O.D.
Connection method
Between the indoor & outdoor units
Input
Running current
Starting current
Fan(drive) x No.
Fan motor output
Airflow(Low-High)
External static pressure
Input
Running current
Starting current
Model
Motor output
Starter type
Protection devices
Fan(drive) x No.
Fan motor output
Airflow
Charge
W
D
H
W
D
H
Liquid
Gas
Indoor side
Outdoor side
Height difference
Piping length
Function
Capacity
Total input
INDOOR UNITOUTDOOR UNIT
REFRIGERANT
PIPING
Item Service Ref.
Btu/h
W
kW
kW
A
A
kW
K/ min (CFM)
Pa(mmAq)
kW
dB(A)
mm,(in)
mm,(in)
mm,(in)
mm,(in)
kg,(lbs)
kW
A
A
kW
kW
K/ min (CFM)
dB(A)
mm,(in)
mm,(in)
mm,(in)
kg,(lbs)
kg,(lbs)
mm,(in)
mm,(in)
PLH-6GK(H)SB1.UK
Cooling
46,100
13,500
5.03
Heating
54,300[64,500]
15,900[18,900]
4.88[7.88]
0.30
1.36
1.50
0.30[3.30]
1.36[13.9]
1.50[14.0]
UNIT : 1340(52-3/4)
UNIT : 820(32-1/4)
UNIT : 258(10-1/8)
UNIT : 45(99)
PANEL : 1470(57-7/8)
PANEL : 950(37-3/8)
PANEL : 65(2-9/16)
PANEL :10(22)
4.73
7.74
74
4.58
7.50
74
PLH-6GK(H)SB1.UK
Single, 50Hz, 220-240V
Galvanized sheets with gray heat insulation
Plate fin coil
Turbo fan (direct) x 2
0.050+0.050
25-35(880-1235)
0(direct blow)
[3.0]
Remote controller & built-in
38-45
30(1-1/4)
PUH-6YKSA2.UK
3, 50Hz, 380-415V(4wire)
Munsell 5Y 7/1
Capillary tube
Hermetic
ZR68KC-TFD
4.0
Line start
Internal thermostat, Anti-phasa protector, Thermal switch, HP switch
Plate fin coil
Propeller (direct) x2
0.10+0.10
100(3530)
Reverse cycle
56
970(38-3/16)
345+24(13-9/16 add 1)
1258(49-1/2)
117(258)
R-22
5.0(11.0)
9.52(3/8)
19.05(3/4)
Flared
Flared
Max. 50m
Max. 50m