Trane CenTraVac Duplex CDHE, Operation & Maintenance Manual

Page: 89 / 116

89
CDHF-SVU01C-EN
Unit Start-Up Procedures
Daily Unit Start-Up
1. Verify the chilled water pump and
condenser water pump starter are
in “ON” or “AUTO”.
2. Verify the cooling tower is in “ON”
or “AUTO”.
3. Check both oil tank oil level(s); the
level must be visible in or above
the lower sight glass. Also, be
sure to check the oil tank
temperature; normal oil tank
temperature before start-up is
140°F to 145°F (60 to 63°C).
4. Note: Each oil heater is energized
during the compressor off cycle.
During unit operation, the oil tank
heater is de-energized.
5. Check the chilled water setpoint
and readjust it, if necessary, in the
Chiller Settings menu.
6. If necessary, readjust the current
limit setpoint in the Chiller
Setpoints menu.
7. Press “AUTO”.
Unit Startup
The UCP also checks compressor
motor winding temperature, and a
minimum restart time is initiated if
the winding temperature is less than
265°F. The chilled water pump relay
is energized and evaporator water
flow is proven.
Next, the UCP checks the leaving
evaporator water temperature and
compares it to the chilled water
setpoint. If the difference between
these values is less than the start
differential setpoint, cooling is not
needed.
If the UCP determines that the
difference between the evaporator
leaving water temperature and chilled
water setpoint exceeds the start
differential setpoint, the unit enters
the initiate Start Mode and the oil
pump and Refrigerant pump and the
condenser water pump are started. If
condenser water flow is not proven
(flow switch 5S3 does not close)
within 4-minutes 15 seconds, the unit
is locked out on a MMR Diagnostic.
Oil pressure must be verified within 3
minutes or a MMR diagnostic is
generated.
When less than 5 seconds remain on
the restart inhibit, the pre-start starter
test is conducted on Y-Delta starters.
If faults are detected, the unit’s
compressor will not start, and a
MMR Diagnostic will be generated.
If the compressor motor starts and
accelerates successfully, “Unit is
Running” appears on the display. At
this time the purge unit will start
operating on “Automatic” and will
continue to operate as long as chiller
compressor is running.
Note: Whenever the UCP detects a
MMR diagnostic condition during
start-up, unit operation is locked out,
and manual reset is required before
the start-up sequence can begin
again. If the fault condition has not
cleared, the UCP will not permit
restart.