Table 12 - Safety Shutdown Messages - York YZ MODEL A Operation And Maintenance Manual

FORM 161.01-OM1
ISSUE DATE: 6/8/2018

TABLE 12 - SAFETY SHUTDOWN MESSAGES

The chiller can be started after manual resets are per-
formed as detailed below.
MESSAGE
The Auxiliary Safety shutdown input, connected to I/O Board TB2-31 senses 115 VAC, initiating a
AUXILIARY SAFETY –
safety shutdown. This input is a general-purpose, user defined safety shutdown input. The chiller
CONTACTS CLOSED
can be started after the contacts open and the CLEAR FAULT key is pressed.
The condenser pressure, as sensed by the Condenser Transducer, has increased to greater than
CONDENSER – HIGH
40.0 PSIA. The chiller can be started after the pressure decreases to is less than 30.0 PSIA and
PRESSURE
the CLEAR FAULT key is pressed.
The contacts of the electromechanical high pressure safety device, located on the con-denser
CONDENSER – HIGH
shell, have opened because this device has detected a pressure greater than 40±5 PSIG. The
PRESSURE CONTACTS
contacts will automatically close when the condenser pressure decreases to is less than 20±5
OPEN
PSIG. The chiller can be started after the contacts close and the CLEAR FAULT key is pressed.
CONDENSER – The Condenser Pressure Transducer is indicating a pressure that is less than 0.0 PSIA or greater
PRESSURE
than 80.0 PSIA This is outside the normal operating range of the transducer. This is generally
TRANSDUCER OUT OF indicates a defective transducer. The chiller can be started after the transducer is indicating a
RANGE pressure that is within range and the CLEAR FAULT key is pressed.
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
CONTROL PANEL –
condition for their devices. This fault is not expected on an actual loss of microboard power from
LOSS OF CONTROL
the critical load bus, because the processor will be off before the fault delay. This message can
VOLTAGE
indicate a Cycling (auto-restart after power failure) or Safety (manual restart after power failure)
shutdown, depending upon control center configuration
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-
CONTROL PANEL – restart after power failure) or Safety (manual restart after power failure) shutdown, depending
POWER FAILURE 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.
The evaporator pressure, as sensed by the Evaporator Transducer, has decreased to the
shutdown threshold and caused 3 cycling shutdowns in a 90 minute period. For water cooling ap-
plications, the shutdown threshold is a fixed value. For Brine cooling applications, the shutdown
threshold varies according to the concentration of the Brine solution. The Brine shutdown thresh-
old is programmed at the YORK Factory. The chiller can be started after the evaporator pressure
EVAPORATOR – LOW
increases to the restart threshold and the CLEAR FAULT key is pressed.
PRESSURE
A possible defective Evaporator Pressure Transducer ir Refrigerant Temperature Sensor has
been detected. The control center converts the evaporator pressure to a Saturated Temperature
value and compares this value to the optional Evaporator Refrigerant Temperature Sensor. If the
difference between these temperatures is greater than 3.0°F (1.77 °C), continuously for 1 minute,
EVAPORATOR – this shutdown is performed. This check is only performed under the following conditions:
TRANSDUCER OR
TEMPERATURE
SENSOR
The chiller can be started after the temperatures are within 3.0 °F (1.77 °C) of one an-other and
the CLEAR FAULT key is pressed.
JOHNSON CONTROLS
SECTION 3 - OPTIVIEW™ CONTROL CENTER FUNCTIONS AND NAVIGATION
FLUID
Water Cooling
Brine Cooling
• Chiller has been running for at least 10 minutes
• Evaporator Refrigerant temperature (RT7) is enabled
• NOT in Brine cooling mode
• Evaporator Temperature Sensor (RT7) or Evaporator Saturation Temperature is indicating a
temperature of less than 32.0 °F (0 °C).
DESCRIPTION
SHUTDOWN (PSIA)
6.4 to 7.4
as programmed
6.4 to 7.4
as programmed
3
RESTART (PSIA)
+0.1>
Shutdown threshold
+0.1>
Shutdown threshold
101