Trane CenTraVac Duplex CDHE, Operation & Maintenance Manual

Page: 81 / 116

81
CDHF-SVU01C-EN
High Vacuum Lockout
The oil sump pressure is below the
lockout setpoint. Starting of
compressor is inhibited as a result.
Low Oil Temperature Start Inhibit
The oil temperature is at or below the
low oil temperature start inhibit
setpoint (143°F/61.7°C). The heater is
energized to raise the oil temperature.
Low oil temperature is indicative of
refrigerant dilution in the oil. Oil
temperature is used to estimate this
dilution since the oil temperature
directly corresponds to amount of
refrigeration 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 the oil temperature is at 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 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
the greater of 100°F/37.8°C or the
Saturated Evaporator Refrigerant
Tempe 30°F/16.7°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 via
the service tool.
Machine Protection
and Adaptive
Control