Carrier Streamline Scroll 69NT20-531-300 - Manual (Page 71)

6-7 T-309
n. Place the new service seals (kit item 2) at the com-
pressor service ports, connect the four service valves
loosely.
o. Torque the four resilient mount screws to 6.2 mkg (45
ft--lbs).
p. Torque the four service valves to:
Service Valve Torque
Suction or Discharge 11 to 13.8 mkg
(80 to 100 ft--lbs.)
Economizer 6.9 to 8.3 mkg
(50 to 60 ft--lbs.)
Oil Return 1.4 to 1.66 mkg
(10 to 12 ft--lbs.)
q. Reassemble the top mounting bracket (see
Figure 6-7) by hand tightening the 32--mm (1 ¼
--inch) bolt and torquing the four mounting screws to
0.9 mkg (6.5 ft--lbs). Align the mounting so that the
ring and bushing assembly are free with no compres-
sion.
r. Torque the 32mm bolt to 1.5 mkg (11 ft--lbs.). While
maintaining the free movement of the shock mount,
torque the four mounting screws to 0.9 mkg (6.5 ft--
lbs.).
s. Replace the power plug O--Ring with new ring (kit
item 9). Insert the power plug into the compressor fit-
ting. Be sure plug is fully seated into the fitting and
then thread the coupling nut a minimum of 5 turns.
t. Leak check and evacuate the compressor to 1000 mi-
crons. Refer to paragraphs 6.5 and 6.6
u. Run the unit for at least 15 minutes and check the oil
and refrigerant levels. Refer to paragraphs 6.7 and
6.9.
6.9 COMPRESSOR OIL LEVEL
CAUTION
Use only Carrier Transicold approved
Polyol Ester Oil (POE) -- Mobil ST32 com-
pressor oil with R-134a. Buy in quantities of
one quart or smaller. When using this hygro-
scopic oil, immediately reseal. Do not leave
container of oil open or contamination will
occur.
a. Checking the Oil Level in the Compressor
1 Ideally, ambient temperature should be between
40_F and 100_F.
2 Operate the unit in cooling mode for at least 20 min-
utes.
3 Check the controller function code Cd1 for the suc-
tion modulation valve (SMV) position. It should be
at least 20% open.
4 Locate the oil sight glass on the side of the compres-
sor (item 7, Figure 2-3 ).
5 Turn Start/Stop switch off and allow oil to drain into
compressor sump. Oil level must be visible in the
sight glass. If it is not visible, oil must be added to the
compressor.
b. Adding Oil with Compressor in System
1. The recommended method is to add oil using an oil
pump at the oil return service valve (see item 15,
Figure 2-3 )
2. In an emergency where an oil pump is not available,
oil may be drawn into the compressor through the oil
return service valve.
Connect the suction connection of the gauge man-
ifold to the compressor oil return valve port, and
immerse the common connection of the gauge man-
ifold in an open container of refrigeration oil.
Extreme care must be taken to ensure the manifold
common connection remains immersed in oil at all
times. Otherwise air and moisture will be drawn into
the compressor. Crack the oil return service valve
and gauge valve to vent a small amount of refrigerant
through the common connection and the oil to purge
the lines of air. Close the gauge manifold valve.
With the unit running, turn the suction service valve
toward frontseat and induce a vacuum in the com-
pressor crankcase. Do not allow the compressor to
pull below 127mm/hg (5 “/hg). SLOWLY crack the
suction gauge manifold valve and oil will flow
through the oil return service valve into the compres-
sor. Add oil as necessary.
3 Run unit for 20 minutes in cooling mode. Check oil
level at the compressor sight glass.
c. Removing Oil from the Compressor:
1 If the oil level is above the sight glass, oil must be
removed from the compressor.
2 Perform a compressor pump down, refer to section
6.4.
3 Remove the oil plug, and drain oil until a level can be
seen in the sight glass.
4 Run unit for 20 minutes in cooling mode. Check oil
level at the compressor sight glass.
6.10 HIGH PRESSURE SWITCH
6.10.1 Replacing High Pressure Switch
a. Turn unit start-stop switch OFF. Frontseat the suc-
tion, discharge, economizer and oil return service
valves to isolate compressor. Remove the refrigerant
from the compressor.
b. Disconnect wiring from defective switch. The high
pressure switch is located on the discharge service
valve and is removed by turning counterclockwise.
(See Figure 2-3.)
c. Install a new high pressure switch after verifying
switch settings. (Refer to paragraph 6.10.2.)
d. Evacuate and dehydrate the compressor per para-
graph 6.6.