York YK-EP B Operation & Maintenance Manual page 167

FORM 160.87-OM1
ISSUE DATE: 8/24/2018
than the Condenser Saturated temperature by 30 or
40°F, as described above in the Oil – Low Temperature
Differential message description.
Control Panel – Power Failure
A Control Power failure has occurred. If the power fail-
ure occurred while the chiller was running, it will auto-
matically restart when power is restored. However, if the
power failure duration was less than the duration of the
applicable coastdown period (2.5 minutes standard; 15
minutes steam turbine) when power is restored, the re-
mainder of the coastdown will be performed, prior to the
chiller starting. This message can indicate a Cycling (au-
to-restart after power failure) or Safety (manual restart
after power failure) shutdown, depending upon Control
Center configuration. It indicates a cycling shutdown
when displayed in orange characters; safety shutdown
when displayed in red characters. The Control Center is
configured for auto-restart or manual restart after power
failure by a qualified Service Technician.
Leaving Chilled Liquid – Low Temperature
The Leaving Chilled Liquid Temperature has decreased
to the programmed Shutdown Temperature Setpoint.
If the chiller is running when this occurs, the Pre-
Rotation Vanes are driven fully closed prior to shutting
down the chiller. The chiller will automatically restart
when the temperature increases to the programmed Re-
start Temperature Setpoint.
Leaving Chilled Liquid – Flow Switch Open
The Chilled Liquid Flow Switch has remained open for
5 continuous seconds while the chiller was running or
failed to close during the System Prelube period. The
chiller will automatically restart when the flow switch
closes.
While this cycling shutdown is active, the evaporator
pump relay contacts (TB2-44/45) remain closed un-
til the chiller is given a stop command or has another
fault.
Condenser – Flow Switch Open
The condenser water flow switch has remained open
for 30 continuous seconds while the chiller was run-
ning. This check is bypassed for the first 30 seconds
of System Run. The chiller will automatically restart
when the flow switch closes.
While this cycling shutdown is active, the condenser
pump contacts (TB2-150/151) remain closed until the
chiller is given a stop command or has another fault.
JOHNSON CONTROLS
SECTION 3 - DISPLAY MESSAGES
Motor Controller – Contacts Open
The CM-2 Current Module (Electromechanical starter
applications) or Solid State Starter Logic Board (Mod
"A" Solid State Starter applications) has shutdown the
chiller. When detecting a fault condition that places the
starter or motor at risk, these devices open the Motor
Controller contacts "CM" (located on the respective
device and connected between TB6-16 and TB6-53 in
the Control Center) to initiate a shutdown. Since there
are several different faults that are monitored, LED's
on the respective device illuminate to identify the spe-
cific fault that has occurred. Refer to Solid State Start-
er (Mod "A") – Operation and Maintenance (Form
160.46-OM3.1) for details of Mod "A" Solid State
Starter initiated shutdowns and the OptiView Control
Center Service Manual for CM-2 initiated shutdowns.
The chiller will automatically restart when the Motor
Controller contacts close. On some shutdowns, the re-
spective device automatically closes the contacts when
the fault condition clears. Other shutdowns require the
Operator to perform a Manual Reset at the respective
device.
MANUAL
DEVICE
RESET FAULT
Overload
CM-2
Module
Overload
High Temp (more
Solid
than 212°F)
State
Starter
Fault Current
Motor Controller – Loss Of Current
The Compressor Motor current decreased to 10% Full
Load Amps (FLA) for 25 continuous seconds while the
chiller was running. This could be caused by the start-
er de-energizing during run or a defect in the motor
current feedback circuitry to the Control Center. The
chiller will automatically restart at the completion of
System Coastdown.
Power Fault
The CM-2 Current Module (Electro-Mechanical Start-
er applications) or Solid State Starter Logic Board
(Mod "A" Solid State Starter applications) has shut-
down the chiller because it detected a fault condition
that places the motor at risk. These devices open and
close the Motor Controller "CM" contacts (located on
the respective device and connected between TB6-16
and TB6-53 in the Control Center) in less than 3 sec-
onds to initiate the shutdown and produce this message.
AUTOMATIC
RESET FAULT
None
Phase Rotation/Loss
High Temp start inhibit
(more than 110°F)
Trigger Board
Out-of-Lock
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