Trane CVGF-SVU02B-E4 Operation And Maintenance Manual page 69

Restart Inhibit
This function provides short
cycle protection for the motor,
and indirectly also short cycling
protection for the starter since
the starter is designed to operate
the motor under all the
conditions of motor
performance.
Restart Inhibit Function Using
Time Base
This method uses straight start-
to-start timer to determine when
to allow the next start. A Restart
Inhibit Start-to-Start Time
setpoint is used to set the
desired start-to-start time.
Default is 20 minutes and can be
altered using the TechView
time based restart inhibit
function is used if the Restart
Inhibit Type is set to 'Time' using
TechView ™ or if the motor
winding temperatures are
determined to be invalid.
CVGF-SVU02B-E4
Machine Protection and
Adaptive
Note: When the start is inhibited
by the restart inhibit function,
the time remaining will be
displayed along with the restart
inhibit mode. There is no 'free'
start on a power up of the MP
since a real time clock is used to
determine when the next start
will be allowed based on the
start time of the previous start.
Low Oil Temperature Start Inhibit
When oil temperature is at or
below the low oil temperature
start inhibit setpoint (80-
140°F/26.7-60°C), the heater is
energized to raise the oil
temperature.
Low oil temperature is indicative
of refrigerant dilution in the oil.
™ . A
Oil temperature is used to
estimate this dilution since the
oil temperature directly
corresponds to amount of
refrigerant dilution in the oil. It is
required that oil contains
minimal refrigerant in it. This is
accomplished by boiling the
refrigerant out of the oil by
maintaining a high enough oil
temperature.
If enhanced oil temperature
protection is disabled or below a
given Low Oil Temperature
Inhibit setting (default 95°F/35°C)
the compressor cannot be
started. This is an inhibit mode
and will be reported to the
operator interface.
The oil heater is energized in an
attempt to raise the oil
temperature over this inhibit
temperature setpoint. The
compressor is inhibited from
starting until the oil temperature
is raised 5°F (2.7°C) or more
degrees above this setpoint.
The Low Oil Temperature Start
Inhibit is tested on every start
unless a quick restart is being
performed during post-lube.
If the Enhanced Oil Temperature
Protection setting is enabled, the
Low Oil Temperature Start
Inhibit value is 136°F (57.8°C).
If the Enhanced Oil Temperature
Protection setting is not enabled,
the Low Oil Temperature Start
Inhibit value is settable with the
Low Oil Temperature Start
Inhibit Setpoint using the
TechView ™ .
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