Trane CVGF500 Installation, Operation & Maintenance Manual page 43

Oil Management
The primary purpose of Oil Management is to ensure appropriate and sufficient lubri-
cation to the bearings
during compressor operation and to minimize refrigerant dilution in the oil.
The Oil Management system performs safety checks and manages the operation of
the Oil Pump and the Oil Heater. The sensor inputs used for these purposes are the
Differential Oil Switch, and the Oil Temperature.
Two oil heater outputs exist, that should always operate simultaneously, for example,
both on or both off.
Note: The Oil Pump and the Oil Heater are never energized at the same time.
Low Oil Temperature Start Inhibit Setpoint default is: 95° F .
When enhanced oil protection is enabled, the low oil temperature start inhibit is the
saturated evaporator at 30°F (16.6°C) or 105°F (40.5°C), whichever is higher.
When enhanced oil temperature protection is enabled, the oil temperature setpoint is
fixed at 136°F (57.8°C).
The oil temperature control setpoint range is settable from: 100 to 160°F (37.8 to
71.1°C)
Essential Modes
The Oil-Management has the following modes:
1. Low Temperature Start Inhibit: The oil temperature is at or below the low oil tem-
2. Idle: The oil pump is off. The oil temperature is maintained by the heater, at the con-
3. Pre-lube: The oil pump lubricates the bearing for 30 seconds before the compressor
4. Running: The oil pump continues to lubricate the bearings when the compressor is
5. Post-lube: The oil pump lubricates the bearings for 60 seconds after the compressor
If a start command is issued while in post-lube, a quick restart will be performed. The
post-lube mode is indicated to the user on Large display ™ and UT ™.
6. Manual: The oil pump can be commanded on and off in a manual mode.
Oil Temperature Control
The oil heater is used to maintain the oil temperature within +/- 2.5°F (4.5°C) of the oil
temperature control setpoint. The oil heater is commanded off when the oil pump is
commanded on.
Oil Differential Pressure Check
The Oil Differential Pressure Check validates the oil differential pressure before the oil
pump is turned on. This check in necessary in case the differential pressure switch is
not operational. Without this check, the differential oil pressure feedback is gone. This
check is made after post-lube is complete to verify that the differential pressure has
dropped to indicate no oil flow.
Here are the details:
•
CVGF-SVX03B-EN
perature start inhibit setpoint. The heater is energized to raise the oil temperature.
See Low Temperature Start Inhibit section for information about Enhanced Oil Temp
Protection. This mode is indicated to the user.
troltemperature setpoint +/- 2.5°F (1.4°C).
starts. This mode is indicated to the user.
running.
is stopped to ensure bearings remain lubricated as the compressor coasts to a stop.
AdaptiView verifies that the pressure switch is reading no differential pressure with
the oil pump off before proceeding with pre-lube.
General Information
43