Table 12 - Safety Shutdown Messages - York YMC2 Operation And Maintenance

SECTION 3 - OPTIVIEW™ CONTROL CENTER FUNCTIONS AND NAVIGATION

TABLE 12 - SAFETY SHUTDOWN MESSAGES

The chiller can be started after manual resets are per-
formed as detailed below. Service and troubleshooting
information is contained in the YORK YMC2 Service
MESSAGE
AUXILIARY SAFETY –
CONTACTS CLOSED
CONDENSER – HIGH
PRESSURE
CONDENSER – HIGH
PRESSURE CONTACTS
OPEN
CONDENSER – HIGH
PRESSURE –
STOPPED
CONDENSER –
PRESSURE
TRANSDUCER OUT OF
RANGE
CONTROL PANEL -
INVALID BRAM
CONTROL PANEL –
LOSS OF CONTROL
VOLTAGE
CONTROL PANEL –
POWER FAILURE
DISCHARGE – HIGH
TEMPERATURE
DISCHARGE – LOW
TEMPERATURE
100
The Auxiliary Safety shutdown input, connected to I/O Board TB4-31 senses 115 VAC, initiat-
ing a safety shutdown. This input is a general-purpose, user defined safety shutdown input. The
chiller 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 is greater
than 200 PSIG for shells with 235 PSIG DWP and 295 PSIG for shells with 350 PSIG DWP. The
control determines the shell DWP by the condenser model number on the Sales Order Screen.
The chiller can be started after the pressure decreases to is less than 140 PSIG for shells with
235 PSIG DWP and 235 PSIG for shells with 350 PSIG DWP and the CLEAR FAULT key is
pressed.
The contacts of the electro-mechanical high pressure safety device, located on the condenser
shell, have opened because this device has detected a pressure greater than 204±7 PSIG for
shells with 235 PSIG DWP and 308±7 PSIG for shells with 350 PSIG DWP. The contacts will
automatically close when the condenser pressure decreases to is less than 160±10 PSIG for the
235 DWP shells and 230±10 PSIG for the 350 DWP shells. The chiller can be started after the
contacts close and the CLEAR FAULT key is pressed.
The condenser pressure exceeded 170 PSIG for shells with 235 PSIG DWP and 264 PSIG
for shells with 350 PSIG DWP while the chiller was stopped. The control determines the shell
DWP by the condenser model number on the Sales Order Screen. High temperature condenser
water flowing through the condenser while the chiller is shutdown can cause a condenser high
pressure condition resulting in loss of refrigerant. This safety fault anticipates this problem by
annunciating the condenser high pressure condition. The chiller can be restarted after a Service
Technician performs a special reset preset procedure.
The Condenser Pressure Transducer is indicating a pressure that is less than 6.8 PSIG or
greater than 300.0 PSIG. This is outside the normal operating range of the transducer. This is
generally indicates a defective transducer. The chiller can be started after the transducer is indi-
cating a pressure that is within range and the CLEAR FAULT key is pressed.
On bootup, the panel shall determine whether a 512K BRAM module is installed by a sequence
of tests where data is written and read from address above and below 128K. IF the BRAM is not
512K, this shutdown is generated.
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 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-
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 following
instructions in YORK YMC
2
The discharge temperature, as sensed by the Discharge Temperature Thermistor, has increased
to greater than 220.0°F (104°C). The chiller can be started after the temperature decreases to
less than 220.0°F (104°C) and the CLEAR FAULT key is pressed.
The discharge temperature, as sensed by the Discharge Temperature Thermistor, has de-
creased to less than 30.0°F (-1.1°C). The chiller can be started after the temperature increases
to greater than 30.0°F (-1.1°C) and the CLEAR FAULT key is pressed.
Manual (Form 160.84-M2) and Chiller service (Form
160.84-M1).
DESCRIPTION
Service Manual (Form 160.84-M2).
FORM 160.84-OM1
ISSUE DATE: 9/21/2017
JOHNSON CONTROLS