Fig. 8 - Multi-Unit Sequence; Fig. 9 - Condenser Water Flow Interlock - York MILLENNIUM YT J Wiring Diagram

FIG. 8 – MULTI-UNIT SEQUENCE
FIG. 8 – MULTI-UNIT SEQUENCE
For multiple chiller installation application, Multi-Unit
Sequence contacts are available to start and stop each
unit. The maintained closure of a device contacts across
terminals and will permit the unit to operate in
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all the operating modes with the "compressor" switch
in the "RUN" (l) position. Conversely, an opening of
the device contacts will inhibit the unit from operating;
the Graphic Control Center will then display the fol-
lowing message: "CYCLING SHUTDOWN – AUTO
RESTART" and "MULTIUNIT CYCLING – CON-
TACTS OPEN". An accessory sequence control kit
for two, three or four units is available from YORK –
See Fig. 10 for Two Unit Sequence Control kit.
YORK INTERNATIONAL
LD04390
FIG. 9 – CONDENSER WATER FLOW INTERLOCK
FIG. 9 – CONDENSER WATER FLOW INTERLOCK
If desired, a condenser water flow interlock can be ap-
plied. Flow switch – McDonnel type FS8W, max. 150
psi (YORK Part No. 024-15793) available at additional
cost. If condenser water flow switch is not used, a
jumper must be installed between terminals 1 and 11 .
When condenser water is flowing, the flow switch con-
tact will close. Opening of the condenser water flow
switch contacts for 2 continuous seconds will cause unit
shutdown. The Flow Switch Status is checked 30 sec-
onds into "System Run" and continuously thereafter.
The Graphic Control Center will display the following
message: "CYCLING SHUTDOWN – AUTO RE-
START" and "CONDENSER FLOW SWITCH
OPEN".
FORM 160.55-PW7
LD04391
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