After Limited Shutdown; Preparation For Extended Shutdown; After Extended Shutdown; Cold Weather Operation - Carrier AquaEdge 23XRV Start-Up, Operation And Maintenance Instructions Manual

After Limited Shutdown

No special preparations should be necessary. Follow the regular
preliminary checks and starting procedures.

Preparation for Extended Shutdown

The refrigerant should be transferred into the pumpout storage
tank (if supplied; see Pumpout and Refrigerant Transfer Proce-
dures) to reduce chiller pressure and the possibility of leaks. Main-
tain a holding charge of 5 to 10 psi (34 to 69 kPa) of refrigerant or
nitrogen to prevent air from leaking into the chiller.
For seasonal chiller shutdown and lay-up, if the treated water is
not drained then provisions should be made to start the pumps
weekly to circulate the water and reduce corrosion. Consult the
water treatment company for details. Carrier is not responsible for
waterside corrosion.
If freezing temperatures are likely to occur in the chiller area, drain
the chilled liquid, condenser liquid, and the pumpout condenser
liquid circuits to avoid freeze-up. Keep the waterbox drains open.
Leave the oil charge in the chiller with the oil heater and controls
energized to maintain the minimum oil reservoir temperature.

After Extended Shutdown

Ensure the liquid system drains are closed. It may be advisable to
flush the liquid circuits to remove any soft rust which may have
formed. This is a good time to brush the tubes and inspect the
Schrader fittings on the optional liquid side flow devices for foul-
ing, if necessary.
Check the cooler pressure on the HMI panel and compare it to the
original holding charge that was left in the chiller. If (after adjust-
ing for ambient temperature changes) any loss in pressure is indi-
cated, check for refrigerant leaks. See Check Chiller Tightness
section, page 25.
Recharge the chiller by transferring refrigerant from the pum-
pout storage tank (if supplied). Follow the Pumpout and Refrig-
erant Transfer Procedures section, page 45. Observe freeze-up
precautions.
Carefully make all regular preliminary and running system
checks. Perform a Control Test before start-up. If the oil level ap-
pears abnormally high, the oil may have absorbed refrigerant. A
LOW OIL TEMP prestart alert will be declared if the oil tempera-
ture is not greater than the EVAPORATOR SATURATED TEMP
plus 15°F (8.3°C) or 140°F (60°C), whichever is lower.

Cold Weather Operation

When the entering condenser liquid drops very low (55°F [13°C]
minimum), the operator or tower control should automatically cy-
cle the cooling tower fans off to keep the temperature up. Piping
may also be arranged to bypass the cooling tower.
For cold weather operation it is also recommended to use the
chiller HPR output to control the condenser water flow to keep the
chiller pressure differential at a satisfactory level.

Refrigeration Log

A refrigeration log, such as the one shown in Fig. 47, provides a
convenient checklist for routine inspection and maintenance, and
provides a continuous record of chiller performance. It is an aid
in scheduling routine maintenance and in diagnosing chiller
problems.
Keep a record of the chiller pressures, temperatures, and liquid
levels on a sheet similar to that shown. Automatic recording of
PIC6 data is possible through the use of CCN/LEN devices such
as ProView service tool. Contact your Carrier representative for
more information.
43