Airmark GFS Series Installation manual - page 6
6
IO-123163 Effective 01-14-2016
Be aware of the Teflon O-ring. Be sure to
replace the O-ring to attain a proper
seal. (The Teflon O-ring is located between
the two halves of the flowrator)
CAUTION
!
Pay close attention to the piston
orientation. The pointed end of the piston
MUST go into the distributor body, towards
the coil. Failure to ensure this orientation will cause the
piston to be bypassed during operation which might
damage the outdoor unit.
CAUTION
!
II-6. Replace the piston with one
of the correct size. Do not force
the new piston into the body.
Make sure the piston moves
freely in body.
II-7. Assemble the two halves correctly and ensure that the white
Teflon O-ring is present between the two halves (See I-5). Slide the
13/16” nut onto the distributor body.
II-8. Tighten the nut to a torque of approximately 10-30 ft-lbs. Do NOT
overtighten the nut. Overtightening will impede the piston movement
during operation.
II-9. If present, slide the rubber grommet back to position to prevent
air leakage.
8B. TXV Coils
Ensure that the TXV selected is compatible
with the refrigerant used in the outdoor
system (R22 or R410A). TXV caps are
painted green for R22 or pink for R410A. In absence of color,
the caps will be marked with the compatible refrigerant.
CAUTION
!
The sensing bulb and TXV body MUST
be protected from overheating during
brazing. The sensing bulb and TXV body
must be covered using a quench cloth or wet cloth when
brazing. Pointing the brazing flame away from the valve and
sensing bulb provide partial protection only.
!
WARNING
Fig 8B-1. Components of a typical TXV assembly
The valves should be sized according to
the capacity of the outdoor unit. Failure
to install the right valve can lead to poor
performance and possible compressor damage.
CAUTION
!
Ensure that the TXV bulb is in direct
contact with the suction/vapor line. Gap
between the bulb and tube should be
avoided. Failure to do so will impair the proper functioning
of the TXV valve.
CAUTION
!
I. TXV Bulb Horizontal Mounting
The orientation and location of the TXV bulb has a major influence
on the system performance.
It is recommended that the TXV bulb be installed parallel to the
ground (on a horizontal plane). The bulb position should be above and
between 4 o’clock and 8 o’clock. Fig. 8B-2 shows the recommended
position for the TXV bulb installation in the horizontal plane.
The TXV sensing bulb SHOULD be mounted on the suction line
approximately 6” from the TXV or coil housing using the metal clamp
provided. In order to obtain a good temperature reading and correct
superheat control, the TXV sensing bulb must conform to ALL of the
following criteria:
1. The sensing bulb MUST be in direct and continuous
contact with the suction line.
2. The sensing bulb should be mounted horizontally on
the suction line.
3. The sensing bulb MUST be mounted above and between
the 4 and 8 o’clock position on the circumference of the
suction line.
4. The sensing bulb MUST be insulated from outside air.
A properly mounted sensing bulb will prevent false readings caused
by liquid refrigerant that may have formed inside the suction/vapor
line. Insulation will protect the sensing bulb from false readings due
to contact with warm air.
Fig 8B-2. Recommended location for horizontal TXV bulb mount
II-5. Pull the piston out using
a small wire or pick. Verify the
piston size (size is typically
stamped on the body of the
piston - Fig 8A-2). If a different
piston size is required by the
outdoor unit manufacturer,
replace the piston using the small
wire provided with the piston kit.