McQuay WSC Operating Manual page 13

Figure 3, Communication Wiring
NOTE: A fourth chiller, Chiller D would be connected to chiller C same as chiller C to chiller B.
OM Centrif Micro ΙΙ-5
J10
P P
485
PORT
UCM
OPDR
C B A
BLU/WHT
WHT/BLU
SHIELD
(+) (-)
J11 Port
UNIT CONTROL
PIGTAIL
P P
485
UCM
OPDR
B A
C
BLU/WHT
WHT/BLU
SHIELD
Chiller B
(-)
(+)
J11 PORT
UNIT CONTROL
Chiller C
Chiller A
J10 J11
UNIT CONTROL
13