Johnson Controls York YD Manual page 45

Table 9: Safety shutdown messages
Message
DISCHARGE #1 – HIGH
PRESSURE CONTACTS OPEN
DISCHARGE #2 – HIGH
PRESSURE CONTACTS OPEN
DISCHARGE #1 – HIGH
TEMPERATURE
DISCHARGE #2 – HIGH
TEMPERATURE
DISCHARGE #1 – LOW
TEMPERATURE
DISCHARGE #2 – LOW
TEMPERATURE
Model YD Mod D with OptiView Control Center
Description
The contacts of the electro-mechanical high pressure switch (HP1, located in the discharge
line of compressor #1) have opened because it detected a pressure >180.0 psig. The contacts
will automatically close when the discharge pressure decreases to < 120.0 psig and the
Operator presses the Clear Faults button.
The contacts of the electro-mechanical high pressure switch (HP2, located in the discharge
line of compressor #2) have opened because it detected a pressure >180.0 psig. The contacts
will automatically close when the discharge pressure decreases to < 120.0 psig and the
Operator presses the Clear Faults button.
The chiller (both compressors) has shutdown because the discharge temperature of
compressor #1, as sensed by thermistor RT2, has increased to >220.0 ºF. The chiller can be
started after the temperature decreases to <220.0 ºF and the Operator presses the Clear
Faults button.
If compressor #1 is locked out using the Lockout key on the Capacity Compressor Cycling
Screen, this fault does not cause compressor #2 to shutdown or prevent it from starting.
When this fault occurs on a locked-out compressor, it is displayed as a warning. This allows
the user to know that a fault exists on the locked-out compressor. The condition must be
corrected prior to the lockout being removed from the compressor. If it is not, the warning
condition will revert back to a shutdown as soon as the lockout is removed and will cause the
chiller to trip.
The chiller (both compressors) has shutdown because the discharge temperature of
compressor #2, as sensed by thermistor RT8, has increased to >220.0 ºF. The chiller can be
started after the temperature decreases to <220.0 ºF and the Operator presses the Clear
Faults button.
If compressor #2 is locked out using the Lockout key on the Capacity Compressor Cycling
Screen, this fault does not cause compressor #1 to shutdown or prevent it from starting.
When this fault occurs on a locked-out compressor, it is displayed as a warning. This allows
the user to know that a fault exists on the locked-out compressor. The condition must be
corrected prior to the lockout being removed from the compressor. If it is not, the warning
condition will revert back to a shutdown as soon as the lockout is removed and will cause the
chiller to trip.
The chiller (both compressors) has shutdown because the discharge temperature of
compressor #1, as sensed by thermistor RT2, has decreased to <30.0 ºF. The chiller can be
started after the temperature increases to >30.0ºF and the Operator presses the Clear Faults
button.
If compressor #1 is locked out using the Lockout key on the Capacity Compressor Cycling
Screen, this fault does not cause compressor #2 to shutdown or prevent it from starting.
When this fault occurs on a locked-out compressor, it is displayed as a warning. This allows
the user to know that a fault exists on the locked-out compressor. The condition must be
corrected prior to the lockout being removed from the compressor. If it is not, the warning
condition will revert back to a shutdown as soon as the lockout is removed and will cause the
chiller to trip.
The chiller (both compressors) has shutdown because the discharge temperature of
compressor #2, as sensed by thermistor RT8, has decreased to <30.0 ºF. The chiller can be
started after the temperature increases to >30.0ºF and the Operator presses the Clear Faults
button.
If compressor #2 is locked-out using the Lockout key on the Capacity Compressor Cycling
Screen, this fault does not cause compressor #1 to shutdown or prevent it from starting.
When this fault occurs on a locked-out compressor, it is displayed as a warning. This allows
the user to know that a fault exists on the locked-out compressor. The condition must be
corrected prior to the lockout being removed from the compressor. If it is not, the warning
condition will revert back to a shutdown as soon as the lockout is removed and will cause the
chiller to trip.
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