Specifications
90
demand charge for the short period of high demand oper-
ation. Pulldown rate can be based on load rate or temper-
ature rate and is accessed on the EQUIPMENT SER-
VICE screen, RAMP_DEM table (Table 3, Example 24).
To Stop the Chiller
1. The occupancy schedule starts and stops the chiller auto-
matically 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 62. The
chiller will not restart until the or softkey
is pressed. The chiller is now in the OFF control mode.
If the chiller is stopped by an alarm condition, do not re-
start the chiller until the problem is diagnosed and cor-
rected.
After Limited Shutdown — No special preparations
should be necessary. Follow the regular preliminary checks and
starting procedures.
Preparation for Extended Shutdown — The refrig-
erant 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 lbs (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.
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 water sys-
tem 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 fit-
tings on 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 65.
Recharge the chiller by transferring refrigerant from the
pumpout storage tank (if supplied). Follow the Pumpout and
Refrigerant Transfer Procedures section, below. Observe
freeze-up precautions.
Carefully make all regular preliminary and running system
checks. Perform a Control Test before start-up. If the compres-
sor oil level appears abnormally high, the oil may have ab-
sorbed refrigerant. Ensure that the oil temperature is above
140 F (60 C) or above the CALC EVAP SAT TEMP plus 50 F
(27 C).
Cold Weather Operation — When the entering con-
denser water temperature drops very low, the operator should
automatically cycle the cooling tower fans off to keep the tem-
perature up. Piping may also be arranged to bypass the cooling
tower. The PIC II controls have a low limit tower fan output
that can be used to assist in this control (terminal J9-11 and J9-
12 on ISM).
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. 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 con-
trol the position, use the or soft-
key 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.
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, capac-
ity 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 Con-
trols section.
Refrigeration Log — A refrigeration log (as shown in
Fig. 46), is a convenient checklist for routine inspection and
maintenance and provides a continuous record of chiller per-
formance. It is also an aid when scheduling routine mainte-
nance 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. 46. Automatic re-
cording of PIC II 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 refrigerant can be pumped for ser-
vice work to either the chiller compressor vessel or chiller con-
denser vessel by using the optional pumpout system. If a
pumpout storage tank is supplied, the refrigerant can be iso-
lated in the storage tank. The following procedures describe
how to transfer refrigerant from vessel to vessel and perform
chiller evacuation.
IMPORTANT: Do not attempt to stop the chiller by opening
an isolating knife switch. High intensity arcing may occur.
CCN
LOCAL
CAUTION
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
compressor suction must be open to a vessel to give the re-
frigerant a means to leave the compressor.
CAUTION
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
extremely low temperatures in the cooler/condenser tubes
and possibly causing tube freeze-up.
INCREASE
DECREASE
RELEASE