Liquid Tube Strainer; Care And Maintenance - Carrier FA4ANF Service Manual

Damage may occur to the scroll compressor if operated at a
negative suction pressure during a system pumpdown.
2. Bleed and (if possible) recover remaining refrigerant from
tubing and coil through gage port on vapor-tube service valve.
3. Disconnect liquid refrigerant tube from refrigerant flow-
control device. Refer to Fig. 36.
4. Remove refrigerant flow-control device piston retainer. Avoid
damaging O-ring or machined surfaces on piston, bore, and
retainer.
5. Using small wire with a hook on end of it, remove piston from
refrigerant flow-control device body.
RUBBER
PISTON
O-RING
BODY
PISTON
Fig. 36—Refrigerant Flow-Control Device
(For FD3A and FG3A)
When cleaning piston orifice, be careful not to scratch or
enlarge opening as this will affect operation.
Use a backup wrench and do not overtighten as deformation
of refrigerant flow-control device body will occur, causing
piston to lodge in a partially open or closed position.
6. Install new or cleaned piston in refrigerant flow-control device
body.
7. Install new retainer (because of probable damage which
occurred in initial removal).
8. Reconnect refrigerant tube to refrigerant flow-control device.
9. Pressurize tubing and coil, then leak-check.
10. Evacuate tubing and coil as necessary.
Step 4—Liquid Tube Strainer
The refrigerant flow-control device is protected on indoor coil by
a wire mesh strainer. If strainer becomes plugged:
1. Complete items 1 and 2 under Cleaning or Replacing Refrig-
erant Flow-Control Device section.
2. Loosen flare fitting joint connecting refrigerant flow-control
device to coil liquid refrigerant tube.
3. Remove sheet metal screw holding bracket clip in place.
Screw is located between coil and refrigerant flow-control
device.
4. Pull bracket clip out.
5. Remove refrigerant flow-control device assembly.
THREAD
PROTECTOR
RETAINER
A92219
6. Pull strainer out of coil liquid refrigerant tube and replace with
new strainer.
Step 5—Care and Maintenance
Hinged access panel contains electrical components and is
heavy. Support panel when lowering to clean unit to avoid
personal injury.
Disconnect electrical power to all circuits before servicing
unit. Failure to do so may result in personal injury from
electrical shock or moving parts.
As with any mechanical equipment, personal injury can result
from sharp metal edges. Be careful when removing parts.
The minimum maintenance requirements for this equipment are as
follows:
1. Inspect and clean or replace field-supplied air filter each
month or as required.
2. Inspect cooling coil, drain pan, and condensate drain each
cooling season for cleanliness. Clean as necessary. (To be
performed by trained personnel.)
3. Inspect blower motor and wheel for cleanliness each heating
and cooling season. Clean as necessary.
4. Inspect electrical connections for tightness and controls for
proper operation each heating and cooling season. Service as
necessary.
NOTE: Never operate without a filter or with hinged access door
open. Damage to blower motor may result.
COOLING COIL, DRAIN PAN, AND CONDENSATE DRAIN
Remember to disconnect electrical power before opening hinged
access panel.
The cooling coil is easily cleaned when dry. Inspect coil and clean
(if necessary) before each cooling season. If coil inlet face is
coated with dirt or lint, vacuum with a soft brush attachment.
Be careful not to bend coil fins. If coil is coated with oil or grease,
clean it with a mild detergent-and-hot water solution. Rinse coil
with clear water. Be careful not to splash water onto insulation.
Inspect drain pan and condensate drain at same time cooling coil
is checked. Clean drain pan and condensate drain by removing any
foreign matter from pan. Flush pan and drain tube with clear water.
Clear drain line if restricted.
NOTE: There MUST be a trap in condensate line. Trap must be
at least 3-in. deep, not higher than the bottom of unit condensate
drain opening, and pitched downward to an open drain or sump.
BLOWER MOTOR AND WHEEL
Clean blower motor and wheel when cooling coil is cleaned.
Lubricate motor every 5 years if motor is used on intermittent
operation (thermostat FAN switch at AUTO position), or every 2
years if motor is in continuous operation (thermostat FAN switch
at ON position). Remove motor to lubricate. Put approximately 8
drops of SAE 10 nondetergent oil in each oil hole. Do not overoil
motor. Plug hole securely so that oil does not drip when hinged
access panel is lowered to open position.
Blower motor and wheel may be cleaned using a vacuum with a
soft brush attachment. Remove grease with a mild solvent such as
45