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High Oil Temperature Cutout Fault
The High Oil Temperature Cutout protects the compres-
sor from insufficient lubrication. A system will fault and
shut down with a controlled ramped shutdown when its
oil temperature rises above 225°F. The system will be
inhibited from starting if the oil temperature is above
175°F. The Status display fault message for this safety
is shown below:
SYS X YYYYYYYY HIGH OIL TEMP
X indicates the system and YYYYYYY indicates the
system is in a "FAULT" condition and will restart when
the fault clears or "LOCKOUT" and will not restart until
the operator clears the fault using the keypad.
Low Suction Superheat Cutout Fault
The Low Suction Superheat Cutout helps protect the
compressor from liquid floodback due to low suction
superheat. This safety is ignored for the first 30 seconds
of compressor operation. Low suction superheat will
fault a system when any one of the following condi-
tions occur:
· After the first 30 seconds of run time, if the suction
superheat falls below 2.0°F, the discharge superheat
is < 15°F, and the run time is <5 minutes, the super-
heat safety will be ignored for the next 30 seconds
followed by setting the superheat cutout to 0°F and
linearly ramping it up to 2.0°F over the next 60
seconds. If at any time during these 60 seconds the
suction superheat falls below the ramped cutout, the
system will fault and shut down with a controlled
ramped shutdown.
· If the suction superheat < 2°F, the discharge super-
heat < 15°F for 10 seconds, and the run time is =
or >5 minutes, the system will fault and shutdown
with a controlled ramped shutdown.
· If the suction superheat < 0.5°F and discharge
superheat is > 15°F for 60 seconds and run time =
or > 5 minutes, the system will fault and shutdown
with a controlled ramped shutdown.
· If suction superheat < 5°F for 10 minutes, the system
will fault and shutdown with a controlled ramped
shutdown.
JOHNSON CONTROLS
SYSTEM SAFETIES (FAULTS) (CON'T)
The Status display fault message for this safety is shown
below:
SYS X YYYYYYYY LOW SUCTION SUPERHEAT
X indicates the system and YYYYYYYY indicates the
system is "FAULT" and will restart after the 120 second
anti-recycle timer times out or "LOCKOUT" and will
not restart until the operator clears the fault.
Low Discharge Superheat Cutout Fault
The Low Discharge Superheat Cutout helps protect the
compressor primarily from liquid floodback through
the economizer line due to a high flash tank level. It
also provides protection from liquid floodback through
the suction line in conjunction with the low superheat
safety. This safety is ignored for the first 5 minutes of
compressor operation.
After the first 5 minutes of run time, if the discharge
superheat falls below 10.0°F for 5 minutes, the system
will fault and shut down with a controlled ramped
shutdown.
The Status display fault message for this safety is shown
below:
SYS X YYYYYYYY LOW DISCHARGE SUPERHEAT
X indicates the system and YYYYYYY indicates the
system is in a "FAULT" condition and will restart when
the 120 second anti-recycle timer times out or "LOCK-
OUT" and will not restart until the operator clears the
fault using the keypad.
FORM 201.21-NM1 (1223)
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