After Extended Shutdown; Cold Weather Operation; Manual Guide Vane Operation; Refrigeration Log - Carrier AquaEdge 19XR Start-Up, Operation And Maintenance Instructions Manual

After Extended Shutdown

Ensure the water system drains are closed. It may be advisable
to flush the water circuits to remove any soft rust that may have
formed. This is a good time to brush the tubes and inspect the
Schrader fittings on the waterside flow devices for fouling, 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
adjusting for ambient temperature changes) any loss in pres-
sure is indicated, check for refrigerant leaks. See Check Chiller
Tightness section, page 13.
Recharge the chiller by transferring refrigerant from the pumpout
storage tank (if supplied). Follow the Pumpout and Refrigerant
Transfer Procedures section. Observe freeze-up precautions.
Carefully make all regular preliminary and running system
checks. If the compressor oil level appears abnormally high,
the oil may have absorbed refrigerant. Ensure that the oil tem-
perature is above 40°F (4.4°C) or above the EVAP SAT TEMP
plus 50F (27C).

Cold Weather Operation

When the entering condenser water temperature drops very
low, the operator should automatically cycle the cooling tower
fans off to keep the temperature up. Piping may also be ar-
ranged to bypass the cooling tower.
IMPORTANT: A field-supplied water temperature control
system for condenser water should be installed. The system
should maintain the leaving condenser water temperature at
a temperature that is at least 20F (11C) above the leaving
chilled water temperature.

Manual Guide Vane Operation

It is possible to manually operate the guide vanes in order to
check control operation or to control the guide vanes in an
emergency. Manual operation is possible by overriding the tar-
get guide vane position.
NOTE: Manual control overrides the configured pulldown rate
during start-up and permits the guide vanes to open at a faster
rate. Motor current above the electrical demand setting, capaci-
ty overrides, and chilled water temperature below the control
point override the manual target and close the guide vanes. For
descriptions of capacity overrides and set points, see the 19XR
with PIC 5 Controls Operation and Troubleshooting guide.

Refrigeration Log

A refrigeration log (as shown in Fig. 26), is a convenient
checklist for routine inspection and maintenance and provides
a continuous record of chiller performance. It is also an aid
when scheduling routine maintenance and diagnosing chiller
problems.
Keep a record of the chiller pressures, temperatures, and liquid
levels on a sheet similar to the one in Fig. 26. Automatic re-
cording of data is possible by using CCN devices such as the
Data Collection module and a Building Supervisor. Contact a
Carrier representative for more information.
PUMPOUT AND REFRIGERANT
TRANSFER PROCEDURES

Preparation

The 19XR chiller may come equipped with an optional pumpout
storage tank, pumpout system, or pumpout compressor. The re-
frigerant can be pumped for service work to either the chiller
compressor vessel or chiller condenser vessel by using the op-
tional pumpout system. If a pumpout storage tank is supplied,
the refrigerant can be isolated in the storage tank. The following
procedures describe how to transfer refrigerant from vessel to
vessel and perform chiller evacuation.
The power to the pumpout compressor oil heater must be
on whenever any valve connecting the pumpout compres-
sor to the chiller or storage tank is open. Leaving the heater
off will result in oil dilution by refrigerant and can lead to
compressor failure.
If the compressor is found with the heater off and a valve
open, the heater must be on for at least 4 hours to drive the
refrigerant from the oil. When heating the oil the compres-
sor suction must be open to a vessel to give the refrigerant a
means to leave the compressor.
Always run the chiller cooler and condenser water pumps
and always charge or transfer refrigerant as a gas when the
chiller pressure is less than 35 psig (241 kPa). Below these
pressures, liquid refrigerant flashes into gas, resulting in ex-
tremely low temperatures in the cooler/condenser tubes and
possibly causing tube freeze-up.
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CAUTION
CAUTION