York YMC2 User Manual

JOHNSON CONTROLS
93
SECTION 3 - OPTIVIEW™ CONTROL CENTER FUNCTIONS AND NAVIGATION
FORM 160.84-OM1
ISSUE DATE: 9/21/2017
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
• 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
• Condenser Flow Switch is Closed
CONTROL PANEL – LOSS OF
CONTROL VOLTAGE
The line power input signal at I/O board TB3-81 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 char-
acters. The control center is congured for auto-restart or manual restart after power
failure by a qualied Service Technician following instructions in YORK YMC
2
Service
Manual (Form 160.84-M2).
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
The evaporator pressure, as sensed by the Evaporator Transducer, has decreased to
the shutdown threshold. For water cooling applications, the shutdown threshold is a
xed value. For Brine cooling applications, the shutdown threshold varies according to
the concentration of the Brine solution. The Brine shutdown threshold is programmed at
the YORK Factory. It should not be changed by anyone other than a qualied Service
Technician following instructions in YORK YMC
2
Service Manual (Form 160.84-M2). The
chiller will restart after the evaporator pressure increases to the restart threshold. If this
shutdown occurs 3 times in a 90 minute period, an EVAPORATOR-LOW PRESSURE
safety shutdown is initiated.
SHUTDOWN
SHUTDOWN
(PSIG)
RESTART
(PSIG)
Water Cooling 25.0 25.1
Brine Cooling
6.0 to 25.0
as programmed
+0.1>
Shutdown threshold
TABLE 11 - CYCLING SHUTDOWN MESSAGES
The chiller will automatically restart when the cycling
condition clears.

York YMC2 Specifications

General

Brand	York
Model	YMC2
Category	Chiller
Language	English