Friedrich 2000 TwinTemp EK12J33A-1, Руководство по обслуживанию

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Page 26
TROUBLESHOOTING TOUCH TEST CHART
TO SERVICE REVERSING VALVES
MALFUNCTION OF VALVE
No voltage to coil.
Defective coil.
Low charge
Pressure differential too high.
Pilot valve okay. Dirt in one
bleeder hole.
Piston cup leak
Hot
Hot
Warm
Hot
Hot
Hot
Hot
Hot
Hot
Hot
Hot
Hot
Hot
Warm
Cool
Cool
Cool
Warm
Warm
Hot
Hot
Cool
Cool
Cool
Cool
Cool
Cool
Cool
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-attempt with compressor running. If it still
will not reverse while running, replace the
valve.
Replace valve.
Repair electrical circuit.
Replace coil.
Repair leak, recharge system.
Recheck system.
De-energize solenoid, raise head pressure,
reenergize solenoid to break dirt loose. If
unsuccessful, 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-
attempt with compressor running. If still no
shift, replace valve.
Check Electrical circuit and coil
Check refrigeration charge
Hot
Cool
Cool,
as (2)
*TVB
Hot
Hot,
as (1)
Valve will not
shift from
cool to heat.
Valve will not
shift from
cool to heat.
Starts to
shift but
does not
complete
reversal.
Will not shift
from heat to
cool.
Apparent
leap in
heating.
Clogged pilot tubes.
Both ports of pilot open. (Back seat
port did not close).
Defective Compressor
Not enough pressure differential at
start of stroke or not enough flow to
maintain pressure differential.
Body damage
Both ports of pilot open.
Body damage
Valve hung up at mid-stroke.
Pumping volume of compressor not
sufficient to maintain reversal.
Both ports of pilot open.
Piston needle on end of slide leaking.
Pilot needle and piston needle leaking
Pressure differential too high
.
Clogged pilot tube.
Dirt in bleeder hole.
Piston cup leak
Defective pilot.
Defective compressor.
*TVB
Hot
Warm
Hot
Hot
Hot
Hot
*TVB
**
WVB
*TVB
*TVB
*TVB
Hot
*TVB
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.
NORMAL FUNCTION OF VALVE
DISCHARGE TUBE from Compressor SUCTION TUBE to Compressor
Tube to INSIDE COIL Tube to OUTSIDE COIL LEFT Pilot Capillary Tube
RIGHT Pilot Capillary Tube
VALVE
OPERATING
CONDITION
*TVB
Hot
*TVB
*TVB
Hot
*TVB
Hot
*TVB
**
WVB
*TVB
Hot
Hot
Hot
Warm
Hot,
as (1)
Hot,
as (1)
Warm,
as (1)
Hot
Hot
Hot
Hot
Cool,
as (2)
Cool,
as (2)
Cool,
as (2)
Cool,
as (2)
Cool,
as (2)
Cool,
as (2)
Cool,
as (2)
Cool,
as (2)
Cool,
as (2)
Cool,
as (2)
Warm
Warm
Hot
Hot,
Hot,
as (1)
Hot,
as (1)
Hot,
as (1)
Hot,
as (1)
Hot,
as (1)
Hot,
as (1)
Warm,
as (1)
NOTES:
* TEMPERATURE OF VALVE BODY
** WARMER THAN VALVE BODY
Normal Hot Cool Cool Hot *TVB TVB
Cooling as (2) as (1)
Normal Heating Hot Cool Hot Cool *TVB TVB
as (1) as (2)
1 2 3 4 5 6 POSSIBLE CAUSES CORRECTIONS