Carrier WeatherMaster 50HCQA04, Инструкции по обслуживанию и техническому обслуживанию, Страница: 14 / 98

14
Replacing TXV
PERSONAL INJURY HAZARD
Failure to follow this caution can result in injury to
personnel and damage to components.
Always wear approved safety glasses, work gloves
and other recommended Personal Protective
Equipment (PPE) when working with refrigerants.
CAUTION
!
1. Recover refrigerant.
2. Remove TXV support clamp using a 5/l6-in. nut
driver.
3. Remove TXV using a backup wrench on connections
to prevent damage to tubing.
4. Remove equalizer tube from suction line of coil. Use
file or tubing cutter to cut brazed equalizer line ap-
proximately 2 inches above suction tube.
5. Remove bulb from vapor tube inside cabinet.
6. Install the new TXV and avoid damaging the tubing
or the valve when attaching the TXV to the distribut-
or.
7. Attach equalizer tube to suction line. If coil has
mechanical connection, then use wrench and back up
wrench to attach. If coil has brazed connection, use
file or tubing cutters to remove mechanical flare nut
from equalizer line. Then use coupling to braze the
equalizer line to stub (previous equalizer line) in suc-
tion line.
8. Attach TXV bulb in the same location as original (in
the sensing bulb indent), wrap bulb in protective insu-
lation and secure using the supplied bulb clamp. See
Fig. 18.
9. Route equalizer tube through suction connection
opening (large hole) in fitting panel and install fitting
panel in place.
10. Sweat inlet of TXV marked “IN” to liquid line. Avoid
excessive heat which could damage valve.
TXV SENSING
BULB
CLAMP
THERMAL EXPANSION
(TXV) VALVE
SENSING BULB INSULATION REMOVED FOR CLARITY
C12095
Fig. 18 -- TXV Valve and Sensing Bulb
COOLING CHARGING CHARTS
How To Use Cooling Charging Charts:
Take the outdoor ambient temperature and read the
suction pressure gauge. Refer to chart to determine what
suction temperature should be. If suction temperature is
high, add refrigerant. If suction temperature is low,
carefully recover some of the charge. Recheck the suction
pressure as charge is adjusted.
SIZE DESIGNATION
NOMINAL TONS
REFERENCE
A04 3
A05 4
A06 5
A07 6
D08 7.5
D09 8.5
D12 10
EXAMPLE:
Model 50TCQ*D14
Outdoor Temperature 85
_
F (29
_
C) . . . . . . . . . . . . . . . . . .
Suction Pressure 140 psig (965 kPa) . . . . . . . . . . . . . . . . .
Suction Temperature 55
_
F (13
_
C) . . . . . . . . . . . . . . . . . .
Refer to Fig. 19 through Fig. 26 for Cooling Charging
Charts.
Compressors
Lubrication:
Compressors are charged with the correct amount of oil at
the factory.
UNIT DAMAGE HAZARD
Failure to follow this caution can result in damage to
components.
The compressor is in a Puron (R--410A) refrigerant
system and uses a polyolester (POE) oil. This oil is
extremely hygroscopic, meaning it absorbs water
readily. POE oils can absorb 15 times as much water
as other oils designed for HCFC and CFC refrigerants.
Avoid exposure of POE oil to the atmosphere. This
exposure to the atmosphere can cause contaminants
that are harmful to R--410A components to form.
Keep POE oil containers closed until ready for use.
CAUTION