Extended Shutdown; After Extended Shutdown; Cold Weather Operation; Manual Guide Vane Operation - Carrier 17 Start Up & Operation Manual

Extended Shutdown —
ferred into the utility vessel (see Pumpout and Refrigerant
Transfer Procedures) in order to reduce machine pressure and
possibility of leaks. Maintain a holding charge of 5 to 10 lbs
(2.27 to 4.5 kg) of refrigerant within the cooler/condenser/
compressor sections, to prevent air from leaking into the
machine.
If freezing temperatures are likely to occur in the machine
area, drain the chilled water, condenser water, and the pump-
out condenser water circuits to avoid freeze-up. Keep the
waterbox drains open.
Leave the oil charge in the machine with the oil heater
and controls energized to maintain the minimum oil reser-
voir temperature.
After Extended Shutdown —
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 if necessary.
Check the cooler pressure on the LID default screen, and
compare to the original holding charge that was left in the
machine. If (after adjusting for ambient temperature changes)
any loss in pressure is indicated, check for refrigerant leaks.
See Check Machine Tightness section, page 48.
Recharge the machine by transferring refrigerant from
the utility vessel. Follow the Pumpout and Refrigerant
Transfer Procedures section, page 64. Observe freeze-up
precautions.
Carefully make all regular preliminary and running sys-
tem checks. Perform a controls test before start-up. If the
compressor oil level appears abnormally high, the oil may
have absorbed refrigerant. Make sure that the oil tempera-
ture is above 150 F (66 C) or cooler refrigerant temperature
plus 70° F (39° C).
The refrigerant should be trans-
Be sure that the water
Cold Weather Operation —
denser water drops very low, the PIC can automatically cycle
the cooling tower fans off to keep the temperature up. Piping
may also have to be arranged to bypass the cooling tower as
well as a tower temperature control system.
Manual Guide Vane Operation —
tion of the guide vanes in order to check control operation
or control of the guide vanes in an emergency operation is
possible by overriding the target guide vane position. Ac-
cess the Status01 screen on the LID and highlight TARGET
GUIDE VANE POSITION. To control the position, enter a
percentage of guide vane opening that is desired. Zero per-
cent is fully closed, 100% is fully open. To release the guide
vanes to AUTOMATIC mode, press the RELEASE
softkey.
NOTE: Manual control will increase the guide vanes and
override the pulldown rate during start-up. Motor current above
the electrical demand setting, capacity overrides, and chilled
water below control point will override the manual target
and close the guide vanes. For descriptions of capacity over-
rides and set points, see the Controls section.
Refrigeration Log —
one shown in Fig. 31, provides a convenient checklist for
routine inspection and maintenance and provides a continu-
ous record of machine performance. It is an aid in sched-
uling routine maintenance and in diagnosing machine
problems.
Keep a record of the machine pressures, temperatures, and
liquid levels on a sheet similar to that shown. Automatic re-
cording of PIC data is possible through the use of CCN de-
vices such as the Data Collection module and a Building Su-
pervisor. Contact your Carrier representative for more
information.
62
When the entering con-
Manual opera-
A refrigeration log, such as the