Mitsubishi Electric MXZ-4C36NAHZ Operating manual

TECHNICAL & SERVICE MANUAL
CONTENTS
TECHNICAL CHANGES......................................... 2
1. SAFETY PRECAUTION....................................3
2. OVERVIEW OF UNITS......................................6
3. SPECIFICATIONS............................................10
4. DATA................................................................ 14
5. OUTLINES AND DIMENSIONS...................... 36
6. WIRING DIAGRAM......................................... 40
7. NECESSARY CONDITIONS FOR SYSTEM CONSTRUCTION.... 47
8. TROUBLESHOOTING.................................... 52
9. PRECAUTIONS AGAINST REFRIGERANT LEAKAGE
....140
10. DISASSEMBLY PROCEDURE......................141
No. OCH573
REVISED EDITION-F
MXZ-4C36NAHZ MXZ-4C36NAHZ-U1
MXZ-5C42NAHZ MXZ-5C42NAHZ-U1
MXZ-8C48NAHZ MXZ-8C48NAHZ-U1
MXZ-8C48NA MXZ-8C48NA-U1
MXZ-8C60NA-U1
PAC-MKA50BC
PAC-MKA30BC
PAC-MKA51BC
PAC-MKA31BC
HFC
utilized
R410A
February 2019
Notes:
• This service manual
describes technical data of
outdoor unit and branch box.
As for indoor units, refer to
its service manual.
[Model Name]
<Outdoor unit>
MXZ-4C36NAHZ
MXZ-5C42NAHZ
MXZ-8C48NAHZ
MXZ-8C48NA
MXZ-8C60NA
<Branch box>
PAC-MKA50BC
PAC-MKA30BC
PAC-MKA51BC
PAC-MKA31BC
PARTS CATALOG (OCB573)
[Service Ref.]
OUTDOOR UNIT: MXZ-4C36NAHZ
BRANCH BOX: PAC-MKA51BC
Model name
indication
SPLIT-TYPE, HEAT PUMP AIR CONDITIONERS
Revision:
• Some descriptions have
been modified in REVISED
EDITION-F.
OCH573 REVISED EDITION-E
is void.

2
TECHNICAL CHANGES
MXZ-4C36NAHZ MXZ-4C36NAHZ-U1
MXZ-5C42NAHZ MXZ-5C42NAHZ-U1
MXZ-8C48NAHZ MXZ-8C48NAHZ-U1
MXZ-8C48NA MXZ-8C48NA-U1
Service ref. have been changed as follows.
• The shape of piping around a stop valve (T7W E04 410) has been changed.
• The shape of valve bed has been changed.
OCH573F

6
2OVERVIEW OF UNITS
2-1. SYSTEM CONSTRUCTION
Outdoor unit MXZ-4C36NAHZ(-U1) MXZ-5C42NAHZ(-U1) MXZ-8C48NAHZ(-U1)
MXZ-8C48NA(-U1) MXZ-8C60NA-U1
4HP 4.5HP 5HP 7HP
Rated capacity
(kBtu/h)
Cooling 36 42 48 60
Heating 45 48 54 66
Refrigerant R410A
Connectable
indoor unit
Capacity class Type 06 to Type 36
Caution: The indoor unit which rated capacity exceeds
36 kBtu/ h (Type 36) can NOT be connected.
Number of units 2(*1) to 4 units 2(*1) to 5 units 2(*1) to 8 units 2(*1) to 8 units
Total system wide capacity 33 to 130% of outdoor
unit capacity
(12 to 46.8 kBtu/h)
29 to 130% of outdoor
unit capacity
(12 to 54.6 kBtu/h)
25 to 130% of outdoor
unit capacity
(12 to 62.4 kBtu/h)
20 to 130% of outdoor
unit capacity
(12 to 78 kBtu/h)
Connectable
branch box
Number of units 1 or 2 units
Connectable indoor unit lineups (Heat pump inverter type)
Model type Model name Capacity class [kBtu/h]
06 09 12 15 18 24 30 36
Deluxe Wall-mounted MSZ-FE09/12/18NA
MSZ-FH06/09/12/15NA, 18NA2
Designer MSZ-EF09/12/15/18NA(W/B/S)
Standard Wall-mounted MSZ-GE06/09/12/15/18/24NA
MSZ-GL06/09/12/15/18/24NA
Low static ducted*3 *4SEZ-KD09/12/15/18NA
P-series mid static ducted*3 *4PEAD-A24/30/36AA5
PEAD-09/12/15/18/24/30/36AA7
1-way cassette MLZ-KP09/12/18NA
P-series 22*22 4-way cassette SLZ-KA09/12/15NA
SLZ-KF09/12/15NA
P-series 33*33 4-way cassette PLA-A12/18/24/30/36BA6
PLA-A12/18/24/30/36EA7*5
Floor standing MFZ-KA09/12/18NA
MFZ-KJ09/12/15/18NA
Standard Multi-position air handler*2MVZ-A12/18/24/30/36AA4
●Models other than MXZ-8C60NA (For each connected branch box)
Number of connecting
multi-position unit Constraints
2
Any indoor units other than ducted units are not
connectable.
1
· The total system wide capacity should be 130% or
below including the ducted unit.
· Only 1 ducted unit can be included in the connection.
Option Optional accessories for indoor units and outdoor units are available.
2- branch pipe (joint): Optional parts
In case of using 1- branch box No need
In case of using 2- branch boxes Model name Connection method
MSDD-50AR-E are
MSDD-50BR-E brazing
Branch box PAC-MKA50BC PAC-MKA51BC PAC-MKA30BC PAC-MKA31BC
Number of branches
(Indoor unit that can be connected)
5 branches
(MAX. 5 units)
3 branches
(MAX. 3 units)
Note: A maximum of 2 branch boxes can be connected to 1 outdoor unit.
●MXZ-8C60NA (For each connected branch box)
Number of connecting
multi-position unit
Constraints
2
Any indoor units other than ducted unit are not
connectable.
1
· The total system wide capacity should be 100% or
below including the ducted unit.
· Only 1 ducted unit can be included in the connection.
*3 For MXZ-8C60NA; When connecting the SEZ and PEAD-series units, the total system wide capacity per 1 branch box should be 100% or below including the
ducted unit s. (Only if connecting to PAC-MKA50/51BC)
*4 When not outside units 60: A branch box can connect to maximum 3 of the
ducted unit s. When connecting with 3 of the ducted unit sper 1 branch box, other
indoor units cannot be connected.
When outside units 60: A branch box can connect to maximum 2 of the
ducted unit s. When connecting with 1 and over 1 of the ducted unit s, the total ability
including of the ducted unit s is 100% and below 100%.
*5 When the system includes 1 unit of
ducted unit s, the number of the maximum connectable indoor units is decreased as follows:
3 for MXZ-4C36NAHZ-U1, 4 for MXZ-5C42NAHZ-U1, and 6 for MXZ-8C48NA(HZ)-U1 and MXZ-8C60NA-U1
*1Only one
unit connection is possible with ducted unit.
*2
When connecting a multi-position unit(s), set additional constraints as follows. For connections other than those specied below, consult your dealer.
Select a model according to the
connection method.
OCH573F

<CAUTION> TEST POINT 1is high voltage.
120
8-8. TEST POINT DIAGRAM
Outdoor multi controller circuit board
MXZ-4C36NAHZ MXZ-5C42NAHZ MXZ-8C48NAHZ MXZ-8C48NA
MXZ-4C36NAHZ-U1 MXZ-5C42NAHZ-U1 MXZ-8C48NAHZ-U1 MXZ-8C48NA-U1
MXZ-8C60NA-U1
OCH573F
SW2
Pump down
SW6
Function selection
SW5
Function selection
SW9
Function selection
21S4
4-way valve
SV1
Bypass valve
SS
Base heater
CNAC
Power supply for multi
controller circuit board
208/230 V AC
CNS1
Branch box/ outdoor unit
connecting wire
CNS2
Transmission wire of
centralized control
CN40,CN41
Centralized control power
supply/ For storing
jumper connector selection
CN102
Connect to the M-P.B
(M-NET power circuit board)
CN51
External signal
output
SW4
Model selection
SW7
Manual defrost
SW3
Test run
CN2
Connect to the outdoor
power circuit board
1–5:
Power circuit board →
Transmitting signal to
the multi controller board
(0–5 V DC)
2–5: Zero cross signal
(0–5 V DC)
3–4: Not used
6–5: 16 V DC
7–5: 16 V DC
CNDC
290V–350 V DC
(1(+)–3(−))
VCC (TEST POINT2)
(Voltage between pins of
C82A) : 15 V DC
(Same as CNF1,2 5(+)–4(−))
VSP
(Voltage between pins of
C515 and C516) :
0 V DC (when stopped)
1–6.5 V DC (when operated)
(Same as CNF1,2 6(+)–4(−))
CNF1, 2
Connect to fan motors
1–4: 290V–350 V DC
5–4: 15 V DC
6–4: 0–6.5 V DC
7–4: 15 V DC(when stopped)
0–15 V DC pulse
(when operated)
VDC (TEST POINT1)
(Voltage between pins of C510)
: 290V–350 V DC
(Same as CNF1,2 1(+)–
4(−))
VFG (TEST POINT4)
(Voltage between pin3 and
pin4 of PC511 or PC512) :
(Correspond to CNF1,2 7(+)–4(−))
TH4 Thermistor
<Compressor>
TH7/TH6 Thermistor
<Ambient/ Suction pipe>
63HS
High pressure sensor
63H
High pressure switch
TH3 Thermistor
<Outdoor liquid pipe>
CN3D
Input of silent demand control
CNLVA
Electronic expansion valve
SW1
Display selection
(Self diagnosis)
SWU2, SWU1
Address setting
SW8
Model selection
CN3N
Auto change over
63LS
Low pressure sensor
CNLVB
Electronic expansion valve
TH2 Thermistor
<Hic pipe>
SV2
CN52
52C relay drive signal
1(+)–2(−): 13 V DC
(When 52C relay is ON)
1(+)–3(−): 13 V DC
(When 52C relay is ON)

S R
W V U L2 P N1 L1
121
Outdoor power circuit board
MXZ-4C36NAHZ
MXZ-5C42NAHZ
MXZ-8C48NAHZ
MXZ-8C48NA
MXZ-4C36NAHZ-U1
MXZ-5C42NAHZ-U1
MXZ-8C48NAHZ-U1
MXZ-8C48NA-U1
MXZ-8C60NA-U1
Brief Check of POWER MODULE
If they are short-circuited, it means that they are broken.
Measure the resistance in the following points (connectors, etc.).
1. Check of POWER MODULE
1 Check of DIODE circuit
R- L1 , S- L1 , R - N1 , S- N1
2 Check of IGBT circuit
L2 - N1
3 Check of INVERTER circuit
P- U, P- V, P- W, N1 - U, N1 - V, N1 - W
Note: The marks R , S, L1 , L2 , P, N1 , U, Vand Wshown
in the diagram are not actually printed on the board.
OCH573F
R S
W V U L2 P N1 L1
CNAC1
208/230 V AC
Connect to the
M-NET power
circuit board
(CN1)
NI, LI
Voltage of 208/230 V AC
is input (Connect to the
terminal block (TB1))
EI, E4
Connect to
the electrical
parts box
DCL1, DCL2
Connect to DCL
U/V/W
Connect to the compres-
sor (MC) Voltage among
phases: 10–180 V AC
CNDC
290–350 V DC (1+, 3−)
Connect to the outdoor
controller circuit board
(CNDC)
E2, E3
Connect to the elec-
trical parts box
CN52C
52C driving signal
Connect to the outdoor
controller circuit board
(CN52)
CN2
Connect to the outdoor controller circuit board (CN2)
1–5: Transmitting signal to outdoor controller circuit board ((0–5 V DC)
2–5: Zero cross signal (0–5 V DC)
3–4: 18 V DC
6–5: 16 V DC
7–5: 16 V DC
CN4
Connect to the outdoor
controller circuit board
(CN4)
Power
module
CNAC2
208/230 V AC
Connect to the
outdoor multi
controller circuit
board (CNAC)

122
M-NET power circuit board
MXZ-4C36NAHZ
MXZ-5C42NAHZ
MXZ-8C48NAHZ
MXZ-8C48NA
MXZ-4C36NAHZ-U1
MXZ-5C42NAHZ-U1
MXZ-8C48NAHZ-U1
MXZ-8C48NA-U1
MXZ-8C60NA-U1
OCH573F
CN2
Connect to the outdoor multi
controller circuit board (CN102)
1–2: 24–30 V DC
3–4: 24–30 V DC
CN1
Connect to the outdoor
power circuit board (CNAC1)
1–3: 220–240 V AC
TB1
Connect to the electrical
parts box

124
8-9. INTERNAL SWITCH FUNCTION TABLE
(1) Function of switches
MXZ-4C36NAHZ(-U1) MXZ-5C42NAHZ(-U1) MXZ-8C48NAHZ(-U1) MXZ-8C48NA(-U1)
MXZ-8C60NA-U1
Switch
Step
Function Operation in Each Switch Setting Remarks Purpose Additional Information
ON OFF When to Set
SWU1 ones digit SWU2 tens digit
Rotary switch
SWU2
(tens digit)
0
1
2
3
4
5
6
7
8
9
SWU1
(ones digit)
0
1
2
3
4
5
6
7
8
9
Before turning the power ON
<Initial settings>
SWU2
(tens digit)
0
1
2
3
4
5
6
7
8
9
SWU1
(ones digit)
0
1
2
3
4
5
6
7
8
9
SW1 Digital Display Switch
1–8
1
ON
OFF
2 3 4 5 6 7 8
Can be set either during operation or not.
<Initial settings>
1
ON
OFF
2 3 4 5 6
SW2 Function Switch
1 Selects operating system startup
With centralized controller
Without centralized controller
Before turning the power ON
<Initial settings>
1
ON
OFF
2 3 4 5 6
Turn ON when the centralized controller is connected to the outdoor unit.
•SW2-1 must be turned ON if a
central controller is connected to the system. An example of this would be a TT-24, TW-50A, TE50 or TE200. If SW2-1 is not turned on, while using a central controller, in rare circumstances problems may be encountered such as indoor units not responding to group commands. Therefore, turning SW2-1 ON is recommended if a central controller is used.
•Group setting of 2 or more A-IC
units which is connected to branch box via centrilized controller is not allowed.
2
Connection Information Clear Switch
Clear Do not clear When relocating units or connecting additional
units. —
3 Abnormal data clear switch input
Clear abnormal data
Normal
OFF to ON any time after the power is turned on.
To delete an error history.
4 Pump down ON OFF During compressor
running
To facilitate outdoor unit the pumping down operation. Frequency = Fixed to 65 Hz I
ndoor-electronic expansion valve = Fully open
Outdoor fan step = Fixed to 10
Please refer to a section referring to the pumping down on outdoor units Installation Manuals. It might not be possible to collect all the refrigerant if the amount is excessive.
5 — — — — — — 6 — — — — — —
SW2-5, 6/
SW4/SW8 Model Switch
1–6
MODEL SELECTION 1:ON 0:OFF
SW2
5
ON
OFF
6
5
ON
OFF
6
1
ON
OFF
2
1
ON
OFF
2
SW4
MODELS
MXZ- 4C36NAHZ-U1
SW8
MXZ- 5C42NAHZ-U1
1
ON
OFF
23456
ON
OFF
123456
SW2
5
ON
OFF
6
5
ON
OFF
6
1 2
ON
OFF
ON
OFF
SW4
MODELS SW8
MXZ- 8C48NA-U1
ON
OFF
123456
1
ON
OFF
23456
5
ON
OFF
61
ON
OFF
2
MXZ- 8C48NAHZ-U1
1
ON
OFF
23456
MXZ- 8C60NA-U1
1 2
SW2
5
ON
OFF
6
5
ON
OFF
6
1
ON
OFF
2
1
ON
OFF
2
SW4
MODELS
MXZ-4C36NAHZ
SW8
MXZ-5C42NAHZ
1
ON
OFF
23456
ON
OFF
123456
SW2
5
ON
OFF
61 2
ON
OFF
SW4
MODELS SW8
MXZ-8C48NA
ON
OFF
123456
5
ON
OFF
61
ON
OFF
2
MXZ-8C48NAHZ
1
ON
OFF
23456
Before the power is turned ON.
<Initial settings> Set for each capacity. — —
SW3 Trial operation
1 ON/OFF from outdoor unit ON OFF Any time after the
power is turned ON.
<Initial settings>
1
ON
OFF
2
— —
2 Mode setting Heating Cooling — —
The black square (■) indicates a switch position.
Continue to the next page.
OCH573F