To Stop The Chiller; After Limited Shutdown; Preparation For Extended Shutdown; After Extended Shutdown - Carrier AquaEdge 19XRV series Operation, Maintenance And Installation Manual

4. The OIL PRESSURE should be between 18 and 30 psid
(124 to 207 kPad) differential, as seen on the ICVC
default screen. Typically the reading will be 18 to 25 psid
(124 to 172 kPad) at initial start-up. Typical values may
be up to 10 psid (69 kPad) higher for Frame 3, Frame 4,
Frame 5, and Frame E compressors equipped with rolling
element bearings.
5. The moisture indicator sight glass on the refrigerant
motor cooling line should indicate refrigerant flow and a
dry condition.
6. The condenser pressure and temperature varies with the
chiller design conditions. Typically the pressure will
range between 60 and 135 psig (390 to 950 kPa) with a
corresponding temperature range of 60 to 105 F (15 to
41 C). The condenser entering water temperature should
be controlled below the specified design entering
water temperature to save on compressor kilowatt
requirements.
7. Cooler pressure and temperature also will vary with the
design conditions. Typical pressure range will be between
29.5 and 40.1 psig (203.4 and 276.4 kPa), with tempera-
ture ranging between 34 and 45 F (1.1 and 7.2 C).
8. The compressor may operate at full capacity for a short
time after the pulldown ramping has ended, even though
the building load is small. The active electrical demand
setting can be overridden to limit the compressor IkW, or
the pulldown rate can be decreased to avoid a high
demand charge for the short period of high demand
operation. Pulldown rate can be based on load rate or
temperature rate and is accessed on the EQUIPMENT
SERVICE screen, RAMP_DEM table (Table 4,
Example 23).
9. The economizer (if installed) has two sight glasses that
look into the float chamber. When operating, the top sight
glass is empty and the bottom sight glass is full.

To Stop the Chiller

1. The occupancy schedule starts and stops the chiller
automatically once the time schedule is configured.
2. By pressing the STOP button for one second, the alarm
light blinks once to confirm the button has been pressed.
The compressor will then follow the normal shutdown
sequence as described in the Shutdown Sequence,
Start-Up/Shutdown/Recycle Sequence section, page 61.
The chiller will not restart until the
softkey is pressed. The chiller is now in the OFF control
mode.
IMPORTANT: Do not attempt to stop the chiller by opening
an isolating knife switch. High intensity arcing may occur.
Do not restart the chiller until the problem is diagnosed
and corrected.
After Limited Shutdown — No special preparations should
be necessary. Follow the regular preliminary checks and starting

procedures.

Preparation for Extended Shutdown — The
should be transferred into the pumpout storage tank (if supplied;
see Pumpout and Refrigerant Transfer Procedures) to reduce
chiller pressure and the possibility of leaks. Maintain a holding
charge of 5 to 10 lb (2.27 to 4.5 kg) of refrigerant or nitrogen to
prevent air from leaking into the chiller.
If freezing temperatures are likely to occur in the chiller ar-
ea, drain the chilled water, condenser water, and the pumpout
condenser water circuits to avoid freeze-up. Keep the waterbox
drains open. It is recommended not to store the refrigerant in the
or
CCN LOCAL
refrigerant
82
unit if below-freezing temperatures are anticipated. A nitrogen
holding charge is recommended in this case.
Leave the oil charge in the chiller with the oil heater and con-
trols energized to maintain the minimum oil reservoir
perature.
After Extended Shutdown — Ensure the water system
drains are closed. It may be advisable to flush the water circuits
to remove any soft rust which may have formed. This is a good
time to brush the tubes and inspect the Schrader
the waterside flow devices for fouling, if necessary.
Check the cooler pressure on the ICVC default screen and
compare it to the original holding charge that was left in the
chiller. If (after adjusting for ambient temperature changes) any
loss in pressure is indicated, check for refrigerant leaks. See
Check Chiller Tightness section, page 64.
Recharge the chiller by transferring refrigerant from the pum-
pout storage tank (if supplied). Follow the Pumpout and Refrig-
erant Transfer Procedures section, page 84. Observe freeze-up
precautions.
Carefully make all regular preliminary and running system
checks. Perform a Control Test before start-up. If the compressor
oil level appears abnormally high, the oil may have absorbed re-
frigerant. Ensure that the oil temperature is above 140 F (60 C)
or above the cooler refrigerant temperature plus 50 F (27 C).
Cold Weather Operation — When the entering condenser
water temperature drops very low, the operator should automati-
cally cycle the cooling tower fans off to keep the temperature up.
Piping may also be arranged to bypass the cooling tower. The
PIC III controls have a low limit tower fan output that can be
used to assist in this control (terminals 5 and 6 on the TB2 haz-
ardous voltage field wiring terminal strip).
Manual Guide Vane Operation —
manually operate the guide vanes in order to check control
operation or to control the guide vanes in an emergency. Manu-
al operation is possible by overriding the target guide vane
position. Access the COMPRESS screen on the ICVC and
scroll down to highlight TARGET GUIDE VANE POS. To
control the position, use the
softkey to adjust to the percentage of guide vane opening that is
desired. Zero percent is fully closed; 100% is fully open. To
release the guide vanes to automatic control, press the
softkey.
RELEASE
Similarly, the TARGET VFD SPEED can be manually set in
the COMPRESS screen. The target value is still limited to be be-
tween configured VFD MINIMUM SPEED and VFD MAXI-
MUM SPEED. Once speed is manually set in this manner, ca-
pacity control changes are directed to modulate the guide vanes.
NOTE: Manual control mode overrides the configured pulldown
ramp rate during start-up and permits the guide vanes to open at
a faster rate. The PIC III controls will close the guide vanes if the
motor current exceeds the ACTIVE DEMAND LIMIT or capac-
ity override limits. The guide vanes will also close if the chilled
water temperature falls below the CONTROL POINT. For
descriptions of capacity overrides and set points, see the Con-
trols section.
A refrigeration log (as shown in
Refrigeration Log —
Fig. 47) is a convenient checklist for routine inspection and
maintenance and provides a continuous record of chiller perfor-
mance. It is also an aid when scheduling routine maintenance
and diagnosing chiller problems.
Keep a record of the chiller pressures, temperatures, and liq-
uid levels on a sheet similar to the one in Fig. 47. Automatic
recording of PIC III data is possible by using CCN devices such
as the Data Collection module and a Building Supervisor. Con-
tact your Carrier representative for more information.
tem-
fittings on
It is possible to
or
INCREASE DECREASE