25
Extended shutdown procedure
The following procedure is to be followed if the system is
to be taken out of service for an extended period of time,
eg. seasonal shutdown :
1. Test the condenser and high-side piping for refrigerant
leakage.
2. Open the electrical disconnect switches for the chilled
water pump. Lock the switch in the «OPEN» position.
3. Close all chilled water supply valves. Drain the chilled
water from the evaporator. If the unit will be exposed to
freezing ambient conditions, flush the evaporator with
an antifreeze solution or energize the evaporator heat
tape.
4. Open the unit main electrical disconnect and unit mount-
ed disconnect (if installed) and lock on the «OPEN» posi-
tion.
5. At least every three months (quarterly), check the pres-
sure in the unit and leak test it with an electronic leak
detector to verify that the refrigerant charge is intact.
System restart after extended shutdown
Follow the procedures below to restart the unit after extend-
ed shutdown :
1. Verify that the liquid line service valves, oil line, com-
pressor discharge service valves and suction service
valves (if installed) are open (backseated).
Caution : To prevent damage to the compressor, be
sure that all refrigerant valves are open before starting
the unit.
2. Close the main disconnect and unit mounted discon-
nect (if installed) to energize the compressor sump
heaters.
Caution : The compressor sump heaters must be ener-
gized for a minimum of 24 hours prior to unit opera-
tion, to prevent compressor damage caused by liquid
refrigerant in the compressor at start-up.
3. Maintain power to 1TB3-11 and 1TB3-12 for the evapo-
rator heat tape connections.
4. Fill the evaporator chilled water circuit. Refer to table 4
for evaporator liquid capacities. Vent the system while
it is being filled. Open the vent on the top of the evap-
orator during filling and close when filling is completed.
Caution : Do not used untreated or improperly treated
water. Equipment damage may occur.
5. Close the fused disconnect switch that provides power
to the chilled water pump.
6. Start the chilled water pump and, while chilled water is
circulating, inspect all piping for leakage. Make any nec-
essary repairs before starting the unit.
7. While the chilled water is circulating, adjust the chilled
water flow and check the chilled water pressure drop
through the evaporator.
8. Adjust the flow switch on the evaporator piping (if
installed) for proper operation.
9. Stop the chilled water pump. The unit is now ready for
start-up as described in «Start-up procedures».
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