Troubleshooting Touch Test Chart - Friedrich KQ08J50A-B Service & Parts Manual

TROUBLESHOOTING TOUCH TEST CHART

VALVE
OPERATING
CONDITION
1
Normal Hot Cool
Cooling
Normal Heating Hot Cool
Valve will
not shift
Hot Cool
from cool to
heat.
Hot Cool
Valve will
Hot Cool
not shift
from cool to
heat. Warm Cool
Hot Warm
Starts to
Hot Warm
shift but
does not
Hot Hot
complete
reversal.
Hot Hot
Hot Cool
Apparent
leap in
Hot Cool
heating.
Hot Cool
Hot Cool
Will not shift
from heat to
cool.
Hot Cool
Hot Cool
Warm Cool
Valve operated satisfactorily PRIOR to compressor motor burnout – caused by dirt and small greasy particles inside the valve. TO CORRECT: Remove valve,
thoroughly wash it out. Check on air before reinstalling, or replace valve. Add strainer and filter-drier to discharge tube between valve and compressor.
Page 24
TO SERVICE REVERSING VALVES
2 3 4 5
Cool, Hot, *TVB
as(2) as(1)
Hot, Cool, *TVB
as(1) as (2)
MALFUNCTION OF VALVE
Check Electrical circuit and coil
Check refrigeration charge
*TVB
Cool, Hot,
as (2)
as (1)
Hot,
Cool,
*TVB
as (1)
as (2)
Hot,
Cool,
Hot
as (1)
as (2)
Warm,
Cool, Warm
*TVB
as (1)
as (2)
Hot
Warm
*TVB
Hot
Warm
Hot
Hot
Hot
*TVB
Hot
Hot,
Hot
Cool,
Hot,
*TVB
as (2)
as (1)
Cool,
Hot,
**
as (2)
as (1)
WVB
Cool,
Hot,
*TVB
as (2)
as (1)
Cool,
Hot,
Hot
as (2)
as (1)
Cool,
Hot,
Hot
as (2)
as (1)
Cool,
Hot,
Hot
as (2)
as (1)
Cool,
Warm,
Warm
as (2)
as (1)
NORMAL FUNCTION OF VALVE
* TEMPERATURE OF VALVE BODY
** WARMER THAN VALVE BODY
6 POSSIBLE CAUSES CORRECTIONS
TVB
TVB
No voltage to coil.
Defective coil.
Low charge
Pressure differential too high.
Hot
Pilot valve okay. Dirt in one
bleeder hole.
Piston cup leak
*TVB
Clogged pilot tubes.
Hot
Both ports of pilot open. (Back seat
port did not close).
Defective Compressor
Hot
Not enough pressure differential at
start of stroke or not enough flow to
maintain pressure differential.
Body damage
Hot
Both ports of pilot open.
Hot
Body damage
Valve hung up at mid-stroke. Pumping
volume of compressor not sufficient to
maintain reversal.
Hot
Both ports of pilot open.
*TVB
Piston needle on end of slide leaking.
**
Pilot needle and piston needle leaking
WVB
*TVB
Pressure differential too high
.
Clogged pilot tube.
*TVB
Dirt in bleeder hole.
*TVB
Piston cup leak
Hot
Defective pilot.
*TVB
Defective compressor.
NOTES:
Repair electrical circuit.
Replace coil.
Repair leak, recharge system.
Recheck system.
De-energize solenoid, raise head pressure,
reenergize solenoid to break dirt loose. If un-
successful, remove valve, wash out. Check on
air before installing. If no movement, replace
valve, add strainer to discharge tube, mount
valve horizontally.
Stop unit. After pressures equalize, restart
with solenoid energized. If valve shifts, re-at-
tempt with compressor running. If still no shift,
replace valve.
Raise head pressure, operate solenoid to free.
If still no shift, replace valve.
Raise head pressure, operate solenoid to free
partially clogged port. If still no shift, replace
valve.
Check unit for correct operating pressures and
charge. Raise head pressure. If no shift, use
valve with smaller port.
Replace valve
Raise head pressure, operate solenoid. If no
shift, replace valve.
Replace valve
Raise head pressure, operate solenoid. If no
shift, use valve with smaller ports.
Raise head pressure, operate solenoid. If no
shift, replace valve.
Operate valve several times, then recheck. If
excessive leak, replace valve.
Operate valve several times, then recheck. If
excessive leak, replace valve.
Stop unit. Will reverse during equalization
period. Recheck system
Raise head pressure, operate solenoid to free
dirt. If still no shift, replace valve.
Raise head pressure, operate solenoid.
Remove valve and wash out. Check on air
before reinstalling, if no movement, replace
valve. Add strainer to discharge tube. Mount
valve horizontally.
Stop unit. After pressures equalize, restart with
solenoid de-energized. If valve shifts, re-at-
tempt with compressor running. If it still will
not reverse while running, replace the valve.
Replace valve.