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On solid state starter units only, when the Current Imbal-
ance option is selected via the Solid State Starter screen,
three phase current imbalance protection is provided. A
safety shutdown occurs (following a 45 second by-pass at
startup) whenever the % FLA readout exceeds 80% for
45 seconds continuously and the % imbalance is > 30%.
When all safety controls are satisfied, and the Graphic Con-
trol Center COMPRESSOR switch has been manually
"Reset" (de-energizing alarm) and returned to the RUN
position ("1"), the unit may be restarted, if panel is in "Re-
mote" mode, via the Remote Start contacts (Fig. 6); or, if
panel is in "local" mode by momentarily pressing the key-
pad compressor switch to the START ("") position.
If the unit was shut down because of
Cycling Shutdown Contacts (see Fig.
2) the alarm will not be energized, but
the unit will have been shut down. A
closure of the safety alarm contacts
means that an operator must manu-
ally reset and restart the unit.
When the Safety Shutdown contacts close, the Graphic
Control Center will display the following message:
"SAFETY SHUTDOWN – MANUAL RESTART",
and cause of shutdown.
FIG. 23 – RUN CONTACTS / REMOTE RUN LIGHT
AND SHUTDOWN INDICATOR PLUS EMS
FIG. 23 – RUN CONTACTS/REMOTE RUN LIGHT AND
SHUTDOWN INDICATOR PLUS EMS
When run contacts are required for a Remote Run Light
and/or Shutdown Indicator AND Energy Management
YORK INTERNATIONAL
System (EMS), connect (by others) as shown in the
diagram. The EMS, control relay, shutdown and run
lights are furnished by others. When the N.O. contacts
close, between terminals
minal block TB2 in the Graphic Control Center, this in-
dicates that the unit is operating; the remote Run Light
will be energized. The unit run contacts open when the
unit is shutdown (safety or cycling) and the remote
indicator will then be energized. For run contacts to EMS
only refer to Fig. 4. When terminals
used for an EMS, they may be connected to a remote
Run Light. The control relay scheme shown in Fig. 23
can also be applied for a remote Run Light AND a
Remote Shutdown Indicator, when an EMS is not used.
FIG. 24 – AUXILIARY SAFETY SHUTDOWN INPUT
The closure of a Momentary or Maintained N.O. Switch
or Relay Contacts will cause the unit to shut down and
display: "SAFETY SHUTDOWN – MANUAL RE-
START" and "AUXILIARY SAFETY – CONTACTS
CLOSED". The unit will not restart until the contacts
open and the keypad COMPRESSOR switch is moved
to the "STOP-RESET" position ("O") and then to the
"START" ("
FIG. 25 – EVAPORATOR WATER PUMP INTERLOCK
OR FLOW SWITCH
When Evaporator Water is flowing, the flow switch con-
tact will close. If the flow switch opens for 2 seconds,
LD04398
the unit shuts down and displays "CYCLING SHUT-
DOWN – AUTO RESTART" and "LEAVING
CHILLED LIQUID – FLOW SWITCH OPEN". The
chiller will automatically restart when the switch again
closes. The flow switch status is checked 25 seconds
into "START SEQUENCE INITIATED" and continu-
ously thereafter.
FORM 160.55-PW7
and
on field wiring ter-
35
36
and
35
")position.
are not
36
LD04399
LD04400
15
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