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4.18
ELECTRICAL MAINTENANCE
Be aware of live circuits. High Voltage AC can cause
injury or death. Low Voltage circuit can serious burns.
4.18.1 In-cab controller
Black display when the ON/OFF switch is pressed:
a.
Check voltage on the DC battery (if not
correct the red LED is not on)
b.
Check T1, T2 and T3 on the PC board and
connector on the cab controller
i.
T1 - RED VDC+ 12v
Must have positive voltage. If
there is no positive voltage to
the in-cab you will not have the
RED light at the power button
ii.
T2 - YELLOW VDC- NE
Must be grounded from micro
board. If it is not grounded, you
will not have the RED light at the
power button
iii.
T3 – BLUE SIGNAL WIRE
iv.
It will show positive voltage.
This is
a
signal wire
that communicates between the
in- cab and CPU. If there is no
connection between the in-cab
and micro board you will get a
n0L code when trying to turn on
in-cab controller.
c.
Check fuse FGS
d.
Check fuse FB
e.
Unit is not cooling when the box temperature is higher
than setpoint:
a. Check parameters list (dT and dF)
Defrost cycle is not initiated when the manual defrost
switch is pressed:
a.
Box temperature must be higher than
setpoint temperature, unit must be in cool
mode
b.
Evaporator coil temperature must be
lower than 2.0 ± 3.0°C (36.0 ± 5.0 °F)
c.
Check parameters
Temperature displayed is out of range :
a.
Check the thermostat sensor
b.
Check parameters
4.18.2
Unit is not working in electric mode
a.
Check the Thermomagnetic switch FM1
b.
Check fuse FR on the PC board
c.
Check fuse FS
d.
Check fuse FGR
e.
Check voltage out the diode bridge on wires
4 and B
f.
Check output voltage on transformer
g.
Check voltage on electric motor
h.
Check AC motor Klixon.
4.18.3 Electric standby circuits
If the unit does not run in the electric standby mode use
the following procedure. Make sure the unit is connected
to the proper power source.
Check the power cable receptacle for power. If power is
there, check for power at the unit terminal plug.
If the contactor K1 is pulled down and the overload relay
is closed, but the standby motor fails to start, the trouble
is probably in the standby motor, capacitor or start relay.
If the contactor is not pulling down proceed as follows:
1.
Check the AC line voltage and the
transformer fuse FS. If the AC line
voltage is acceptable and the
transformer fuse is intact, go to step 2.
2.
Measure the transformer output voltage
(AC) at the terminal board. The voltage
reading should be approximately 12/24V
(depending on the unit voltage). If not,
the transformer is defective. If the
