Replacing Txv; Refrigerant System Pressure Access Ports; Puron® (R-410A) Refrigerant; Refrigerant Charge - Bryant Preferred Series Service And Maintenance Instructions

Replacing TXV

CAUTION
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.
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. 20.
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.
TXV SENSOR BULB
SENSOR BULB
INDENT
DIRECTION OF
REFRIGERANT FLOW
SENSOR BULB
INSULATION
Fig. 20 — TXV Sensor Valve Insulation
CAPILLARY TUBE
EQUALIZER TUBE
TO TXV
FROM TXV VALVE
15.9 mm
(REF)

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 compressor.
These are brass fittings with black plastic caps. The hose connec-
tion fittings are standard 1
The brass fittings are two-piece High Flow valves, with a recepta-
cle base brazed to the tubing and an integral spring-closed check
valve core screwed into the base. See Fig. 13. This check valve is
permanently assembled into this core body and cannot be serviced
separately; replace the entire core body if necessary. Service tools
are available from RCD that allow the replacement of the check
valve core without having to recover the entire system refrigerant
charge. Apply compressor refrigerant oil to the check valve core's
bottom o-ring. Install the fitting 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.
UNIT DAMAGE HAZARD
Failure to follow this caution may result in damage to compo-
nents.
The compressor is in a 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 the oil to the atmosphere.
Puron (R-410A) refrigerant is provided in pink (rose) colored cyl-
inders. 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 po-
sition, with the access valve at the top, when adding liquid refrig-
erant for charging. For a cylinder without a dip tube, invert the cyl-
inder, with the access valve located on the bottom, when adding
liquid refrigerant.
Because Puron (R-410A) refrigerant is a blend, it is strongly rec-
ommended that refrigerant always be removed from the cylinder
as a liquid. Admit liquid refrigerant into the system in the dis-
charge 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 refrigerant into
the suction line, use a commercial metering/expansion device at
the gage manifold; remove liquid from the cylinder, 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) refrig-
erant from the cylinder as a vapor.

Refrigerant Charge

Unit panels must be in place when unit is operating during the
charging procedure. To prepare the unit for charge adjustment, use
the following instructions.
NO CHARGE
Use standard evacuating techniques. Evacuate system down to
500 microns and let set for 10 minutes to determine if system has a
refrigerant leak. If evacuation level raises to 1100 microns and sta-
bilizes, the system has moisture in it and should be dehydrated per
GTAC2-5 recommends.
If system continues to rise above 1100 microns, the system has a
leak and should be pressurized and leak tested using appropriate
techniques as explained in GTAC2-5. After evacuating system,
weigh in the specified amount of refrigerant as listed on the unit
rating plate.
16
/ -in. SAE male flare couplings.
4
CAUTION