York YZ MODEL A - TABLE 11 - Cycling Shutdown Messages

JOHNSON CONTROLS
95
SECTION 3 - OPTIVIEW™ CONTROL CENTER FUNCTIONS AND NAVIGATION
FORM 161.01-OM1
ISSUE DATE: 6/8/2018
3
MESSAGE DESCRIPTION
CHILLED LIQUID – FLOW
SWITCH OPEN
The Chilled Liquid Flow Switch has remained open for 5 continuous seconds while the
chiller was running, in soft shutdown, or at least 45 seconds after MBC startup is initi-
ated. The chiller will automatically restart when the ow switch closes or the fault will
clear if the chiller is run command is ceased.
CONDENSER – FLOW SWITCH
OPEN
The Condenser water ow switch has remained open for 5 continuous seconds while
the chiller was running, in soft shutdown, or at least 45 seconds after MBC startup is
initiated. The chiller will automatically restart when the ow switch closes or the fault will
clear if the chiller is run command is ceased.
CONDENSER -FREEZE
THREAT-FLOW SWITCH OPEN
This fault is set when all of the following are true:
• Chiller State is Stopped
• Saturated Condenser Temperature < 35.0 °F (1.6 °C)
• Condenser Flow Switch is Open for 1 minute or longer
It is released when any of the following are true:
• Chiller State is not Stopped
• Saturated Condenser Temperature > 40.0 °F (4.4 °C)
• Condenser Flow Switch is Closed
CONTROL PANEL – LOSS OF
CONTROL VOLTAGE
The line power input signal at I/O board TB3-8 was low for 1 second continuous. This
signal is used to determine when the digital inputs are affected by a line power loss
versus an actual condition for their devices. This fault is not expected on an actual loss
of microboard power from the critical load bus, because the processor will be off before
the fault delay. This message can indicate a Cycling (auto-restart after power failure)
or Safety (manual restart after power failure) shutdown, depending upon control center
conguration
CONTROL PANEL – POWER
FAILURE
A Control Power failure has occurred. If the power failure occurred while the chiller was
running, it will automatically restart when power is restored. This message can indicate
a Cycling (auto-restart after power failure) or Safety (manual restart after power failure)
shutdown, depending upon control center conguration. It indicates a cycling shutdown
when displayed in orange characters; Safety shutdown when displayed in red charac-
ters. The control center may be congured for auto-restart or manual restart after power
failure.
CONTROL PANEL – SCHEDULE
The programmed Daily Schedule Setpoint has shutdown the chiller. If this occurs while
the chiller is running, a Soft Shutdown is performed. The chiller will automatically restart
at the next scheduled start time.
EVAPORATOR – LOW
PRESSURE
Set when the Evaporator Pressure is less than or equal to the Low Evaporator Cutout.
The fault is released when the Evaporator Pressure is greater than the Low Evaporator
Cutout. If this shutdown occurs 3 times in a 90 minute period, an EVAPORATOR-LOW
PRESSURE safety shutdown is initiated.
FLUID TYPE SHUTDOWN (PSIA)
Water Cooling 6.6 (adj 6.4 to 7.4)
Brine Cooling 6.6 (adj 2.9 to 7.4)
EVAPORATOR –
LOW PRESSURE - SMART
FREEZE
Set when the Evaporator Pressure is less than the Evaporator Pressure Override
Threshold for 120 seconds. The fault is released when the Evaporator Pressure is
greater than the Low Evaporator Pressure Override Threshold. If this shutdown occurs
3 times in a 90 minute period, an EVAPORATOR-LOW PRESSURE - SMART FREEZE
safety shutdown is initiated.
EXPANSION I/O – SERIAL
COMMUNICATIONS
Valid communication between the microboard and the LTC I/O Board have been disrupt-
ed for 3 consecutive attempts. The chiller will automatically restart when valid communi-
cation is received.
TABLE 11 - CYCLING SHUTDOWN MESSAGES
The chiller will automatically restart when the cycling
condition clears.