Carrier WeatherMaster Puron 48HC D17, Service And Maintenance Instructions, Page: 16 / 100

16
Replacing TXV
1. Disconnect all AC power to unit. Use approved lockout/
tag-out procedures.
2. Using gage set approved for use with Puron (R-410A)
refrigerant, recover all refrigerant from the system.
3. Remove TXV support clamp.
4. Disconnect the liquid line at the TXV inlet.
5. Remove the liquid line connection at the TXV inlet.
6. Remove equalizer tube from suction line of coil. Use tub-
ing cutter to cut brazed equalizer line approximately 2-in.
(50 mm) above the suction tube.
7. Remove bulb from vapor tube above the evaporator coil
header outlet.
8. Install the new TXV avoiding damage to the tubing or the
valve when attaching the TXV to the distributor. Protect
the TXV against over-temperature conditions by using wet
rags and directing the torch flame tip away from the TXV
body. Connect the liquid line to the TXV inlet by repeating
the above process.
9. Attach the equalizer tube to the suction line. If the replace-
ment TXV has a flare nut on its equalizer line, use a tubing
cutter to remove the mechanical flare nut from the equal-
izer. Then use a coupling to braze the equalizer line to the
stub (previous equalizer line) in the suction line.
10. Attach TXV bulb in the same location as the original (in
the sensing bulb indent), wrap the bulb in protective insu-
lation and secure using the supplied bulb clamp. See
Fig. 21.
11. Route equalizer tube through suction connection opening
(large hole) in fitting panel and install fitting panel in
place.
12. Sweat the inlet of TXV marked “IN” to the liquid line.
Avoid excessive heat which could damage the TXV valve.
13. Check for leaks.
14. Evacuate system completely and then recharge.
15. Remove lockout/tag-out on main power switch and restore
power to unit.
16. Complete charging procedure.
Fig. 21 — TXV Sensor Valve Insulation
Refrigerant System Pressure Access Ports
There are two access ports in the system - on the suction tube
near the compressor and on the discharge tube near the com-
pressor. These are brass fittings with black plastic caps. The
hose connection fittings are standard 1 /
4
-in. SAE male flare
couplings.
The brass fittings are two-piece High Flow valves, with a re-
ceptacle base brazed to the tubing and an integral spring-closed
check valve core screwed into the base. See Fig. 14. This check
valve is permanently assembled into this core body and cannot
be serviced separately; replace the entire core body if neces-
sary. Service tools are available from RCD that allow the re-
placement of the check valve core without having to recover
the entire system refrigerant charge. Apply compressor refrig-
erant oil to the check valve core’s bottom o-ring. Install the fit-
ting body with 96 ± 10 in.-lbs of torque; do not over-tighten.
PURON
®
(R-410A) REFRIGERANT
This unit is designed for use with Puron (R-410A) refrigerant.
Do not use any other refrigerant in this system.
Puron (R-410A) refrigerant is provided in pink (rose) colored
cylinders. These cylinders are available with and without dip
tubes. Cylinders with dip tubes will have a label indicating this
feature. For a cylinder with a dip tube, place the cylinder in the
upright position, with the access valve at the top, when adding
liquid refrigerant for charging. For a cylinder without a dip
tube, invert the cylinder, with the access valve located on the
bottom, when adding liquid refrigerant.
Because Puron (R-410A) refrigerant is a blend, it is strongly
recommended that refrigerant always be removed from the cyl-
inder as a liquid. Admit liquid refrigerant into the system in the
discharge line when breaking refrigerant system vacuum while
the compressor is OFF. Only add refrigerant (liquid) into the
suction line while the compressor is operating. If adding refrig-
erant into the suction line, use a commercial metering/expan-
sion device at the gage manifold; remove liquid from the cylin-
der, pass it through the metering device at the gage set and then
pass it into the suction line as a vapor. Do not remove Puron
(R-410A) refrigerant from the cylinder as a vapor.
CAUTION
PERSONAL INJURY HAZARD
Failure to follow this caution can result in injury to person-
nel and damage to components.
Always wear approved safety glasses, work gloves and oth-
er recommended Personal Protective Equipment (PPE)
when working with refrigerants.
DIRECTION OF
REFRIGERANT FLOW
EQUALIZER TUBE
FROM TXV VALVE
CAPILLARY TUBE
TO TXV
15.9 mm
(REF)
TXV SENSOR BULB
SENSOR BULB
INDENT
SENSOR BULB
INSULATION
CAUTION
UNIT DAMAGE HAZARD
Failure to follow this caution may result in damage to
components.
The compressor is in a Puron
® 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 the oil to the atmosphere.