After Extended Shutdown - Carrier 19EF Series Start Up & Operation Manual

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 36.
Recharge the machine by transferring refrigerant from the
storage vessel. Follow the Refrigerant Transfer Procedure sec-
tion, this page. Observe freeze-up precautions.
Carefully make all regular preliminary and running sys-
tem checks. Perform a control test before start-up. If the com-
pressor oil level appears abnormally high, the oil may have
absorbed refrigerant. Make sure that the oil temperature is
above 140 F (60 C) or cooler refrigerant temperature plus
50° F (27° C).
Cold Weather Operation —
denser water drops very lo (55 F [13 C] minimum), 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.
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.
Access the Status01 table on the LID and highlight
TARGET GUIDE VANE POSITION. To control the posi-
tion, enter a percentage of guide vane opening that is de-
sired. Zero percent 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.
Be sure that the water
When the entering con-
Manual opera-
Refrigeration Log —
one shown in Fig. 27, 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.
REFRIGERANT TRANSFER PROCEDURE
Preparation —
The refrigerant can be pumped into a stor-
age tank for service work. Follow the manufacturer's pum-
pout and storage instructions and the pumpout instructions
provided on the LID when transferring refrigerant.
To read refrigerant pressures during pumpout or leak
testing:
The LID display on the machine control center is suitable
for determining refrigerant-side pressures and low (soft) vacuum.
For evacuation or dehydration measurement, use a quality
vacuum indicator or manometer to ensure the desired range
and accuracy. This can be placed on the Schrader connec-
tions on each vessel (Fig. 5) by removing the pressure trans-
ducer.
Transfer, addition, or removal of refrigerant in spring-
isolated machines may place severe stress on external
piping if springs have not been blocked in both up and
down directions.
48
A refrigeration log, such as the