Piston Body Cleaning And Replacement; Coil & Condensate Pan Removal; And Replacement - International comfort products FEM4 Service And Maintenance Instructions

SERVICE AND MAINTENANCE
evaporator pressure which is transferred via the
equalizer tube to underside of diaphragm, with which
the pin carrier spring pressure closes valve. The
refrigerant flow is effectively stabilized to load demand
with negligible change in superheat.
Figure 18 − Refrigerant Flow−Control Device
FEM4P, WAPM, WAPT, WAPL, REM4P
TEFLON SEAL
PISTON
RETAINER
BRASS
HEX NUT

Piston Body Cleaning and Replacement

CAUTION
!
ENVIRONMENTAL HAZARD
Failure to follow this caution may result in environmental
damage.
Do not vent refrigerant to atmosphere. Recover during
system repair or final unit disposal.
CAUTION
!
UNIT DAMAGE HAZARD
Failure to follow this caution could result in equipment
damage.
Damage may occur to the scroll compressor if operated
at a negative suction pressure during a system
pumpdown.
1. Pump down outdoor unit. Close service valves at
outdoor unit.
2. Recover remaining refrigerant from tubing and coil
through gage port on vapor−tube service valve.
Disconnect refrigerant (liquid) tube from piston body.
(See Figure 18.)
3. Avoid damaging seal ring or machined surfaces on
piston, bore, and retainer.
4. Using small wire with a hook on end of it, remove
piston from body.
CAUTION
!
UNIT DAMAGE HAZARD
Failure to follow this caution could result in equipment
damage.
When cleaning the piston orifice, be careful not to
scratch or enlarge the opening, as this will affect
operation.
5. Install new or cleaned piston into body.
6. Replace seal ring on retainer.
7. Reconnect refrigerant tube to piston body.
8. Pressurize tubing and coil, then leak check.
9. Evacuate tubing and coil as necessary.
496 08 8001 00
PISTON
BRASS
HEX BODY
A93530
Specifications subject to change without notice.
CAUTION
!
UNIT DAMAGE HAZARD
Failure to follow this caution could result in equipment
damage.
Use a backup wrench and do not over tighten, as
deformation of the piston body will occur, causing the
piston to lodge in a partially open or closed position.
LIQUID TUBE STRAINER
In R−22 units, the TXV and refrigerant flow−control device is
protected on the indoor coil by a wire mesh strainer. It is
located inside the 3/8−in. liquid tube at field braze joint just
outside unit casing. Access to strainer is through field braze
joint.
COIL & CONDENSATE PAN REMOVAL

AND REPLACEMENT

Figure 19 − A−Coil Component Location
HORIZONTAL
CONDENSATE
PAN
HORIZONTAL
PAN CLIP
COIL BRACKET
SCREWS–
(4 PER UNIT)
DELTA PLATE TO
PAN (4 PER UNIT)
A−Coil Units
If it is determined that system does not have leaks and
refrigerant is not contaminated, proceed as follows:
1. Recover system refrigerant.
a. Attach manifold/gage set to service valves.
b. Front seat (close) liquid tube service valve.
c. Start unit in cooling mode.
d. Run unit until low pressure switch opens (350kPa)
or vapor pressure reaches 5 psig (35kPa). Do not
allow compressor to pump into a vacuum.
e. Turn off electrical supply to outdoor unit.
f. Front seat (close) vapor service valve.
g. Recover any remaining refrigerant.
NOTE: All outdoor unit coils will hold only factory−supplied
amount of refrigerant. Excess refrigerant, such as in long−line
applications, may cause compressor internal pressure relief
valve to open (indicated by sudden rise in vapor pressure)
before vapor pressure reaches 5 psig (35kPa). If this occurs,
turn off electrical supply to outdoor unit immediately, front seat
vapor service valve, and recover any remaining refrigerant.
2. Turn off electrical supply to indoor unit.
3. Disconnect condensate drain tube.
FAN COILS
EXPANSION DEVICE
(TXV SHOWN)
COIL TOP SEAL
DELTA PLATE
VERTICAL
CONDENSATE
PAN
A90268
25