IM 439 / Page 11 of 24
Figure 13. Typical Mark IV/AC unit — dual compressor
L1
L2
L3
COMMON
COMP
FAN
O
W
G
WY
FE
L
U
A
P
V
R
C
21
1
COMMON
COMP
FAN
O
W
G
WY
FE
L
U
A
P
V
R
C
21
1
Fan
Motor
Electric
Expan V
alve
Optional
Crankcase
Heater
Compr
. 2
C
ompr
. 1
Chassis
Control
RD7
BK12
RD6
BK92
BK93
Compr
.
Cont. 1
Compr
. Cont. 2
BK82
BK83
}
YE14
Optional
Positive
Staging
Relay
GR/YE
YE13YE13
BK1
1
BK
RD
YE
WH
WH56
WH
WH57
WH55
Circuit 2
Thermistor
Thermistor
Electric
Expan V
alve
WH
WH46
WH
WH47
WH45
Low T
e
mp
Circuit 1
2
1
2
1
Circuit
1
Circuit
2
High Press
Switch
Low Press
Switch
Reversing V
a
lve
Solenoid
(not required on cooling only)
<<
<<
<<
<<
<<
<<
<<
<<
High Press
Switch
Low Press
Switch
BK
WH
BK
WH
BR
BR
BL
BL
BR53
Low T
e
mp
BR
BR
BL
BL
RD54
BR52
BK51
BL50
BL40
BK41
BR43
RD44
BR42
BK51
BL50
BL40
BK41
YE
<<
<<
Condensate
Overflow
Sensor
BK30
BK49
RD48
BK
BK
BK59
RD58
BK
BK
1
2
5
3
4
BR87
RD88
PK89
WH85
WH86
BK83
BL18
YE13
BK1
1
BK82
BK31
YE8
BK4
BK
WH
RD
OR
YE14
BK12
BK92
BK32
YE9
BK5
WH
RD
OR
BK93
BL17
BK
BK
RD
YE
BK10
RD208
OR240
RD208
OR240
BL
YE
BK
BL
YE
BK
WH16
YE28
YE23
WH16
BK34
BL19
Control 1
BR42
BR43
BK41
BK40
BK30
BK29
WH66
BL50
BK51
COF
LT
LT
HP
HP
BK24
BK25
RV
RV
V
R
C
Red
3
1
2
4
Red
Red
Red
3
1
2
4
Control 2
BR52
BR53
COF
LT
LT
BK20
RV
RV
V
R
C
HP
HP
BK19
WH56
PK21
YE23
WH64
RD22
WH55
BK59
RD59
BR53
BK51
BL50
BK29
PK89
BR87
RD88
WH46
PK26
YE28
WH65
RD27
WH45
BK49
RD48
WH15
BL17
BK33
GND
Breaker 3A
(optional)
Field
Line
Vo
lt
age
WH15
YE3
BK10
RD2
BK1
BK34
BK33
YE3
YE8
YE9
RD7
RD2
RD6
BK4
BK1
BK5
BK
YE
RD
BL
BL
RD27
RD22
