Thermo King 920000, Руководство пользователя

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Electrical Maintenance
62
Zone 1 Evaporator Does Not Defrost
1. Check the evaporator temperature:
Make sure the evaporator temperature is
actually below 42 F (6 C) if the unit will not
Defrost. Use a test thermometer to check the
evaporator temperature.
2. Check the operation of the defrost termination
switch:
If the unit fails to Defrost, place a jumper wire
between the 12 circuit and the CH circuit at
the defrost termination switch. Press the
M
ANUAL
D
EFROST
key. If the unit shifts to
Defrost, check for a defective defrost
termination switch. If the unit still fails to
Defrost, move to step 3.
3. Check for an open in the 12 circuit between
the defrost termination switch and the TG-V
controller. If the 12 circuit is not open, move
to step 4.
4. Check for an open in 11 circuit between the
TG-V Controller and the defrost relay. If the
11 circuit is not open, move to step 5.
5. Check the defrost relay:
If the unit fails to Defrost, check the PS circuit
at the defrost relay socket for 12 volts. If the
PS circuit has 12 volts, the defrost relay is
defective and should be replaced. A lack of
voltage indicates an open in the PS circuit.
6. If the defrost relay works and the evaporator
fan stops, but the unit continues to Cool;
check the 26 circuit, the 29 circuit, the CIS,
the LLS, and the HGS.
Zone 1 Evaporator Will Not Terminate
Defrost
If the defrost termination switch does not open
and terminate Defrost less than 45 minutes after
Defrost was initiated, the TG-V Controller should
terminate Defrost.
The Multi-Temp TG-V Controller will record
alarm code 14 if the 11 circuit stays grounded and
the Defrost termination on time limit is
unsuccessful.
Zone 1 Evaporator Sticks In Defrost
Indefinitely
If the unit remains stuck in Defrost indefinitely,
check the defrost relay, the 11 circuit and the
TG-V Controller.
NOTE: If the Multi-Temp TG-V Controller has
recorded Alarm Code 14, check the 11 circuit for
a ground first.
1. Unplug the defrost relay and check the 11
circuit:
Unplug the defrost relay and check the B slot
in the defrost relay socket for continuity to CH
(ground). If there is no continuity from the B
slot to CH (ground), replace the defrost relay.
If there is continuity from the B slot to CH
(ground), move to step 2.
2. Disconnect the cab box harness and check the
11 circuit:
Disconnect the cab box harness from the back
of the TG-V Controller and check the 11
circuit for continuity to CH (ground). If the 11
circuit has continuity to CH (ground), check
the 11 circuit for a short to CH (ground). If the
11 does not have continuity to CH (ground),
move to step 3.
3. Check the TG-V Controller:
The integral defrost timer in the TG-V
Controller should terminate the Defrost cycle
after 45 minutes regardless of the evaporator
temperature or amount of frost or ice on the
evaporator coil. If not, test the TG-V
Controller and replace it if necessary. See
“Field Test Procedure for Multi-Temperature
In-Cab TG-V Controllers” on page 72.
Zone 1 Evaporator Continually Fails to
Terminate Defrost In Less than 45 Minutes
If the unit continually fails to complete the
Defrost cycle in less than 45 minutes, and cycles
between Cool and Defrost, check the evaporator
coil temperature, CIS, HGS, PV, RTPS, RTPC,
refrigerant charge, fan relay, defrost termination
switch, and the 12 circuit.