Checking Procedure For The Compressor - Hitachi RAS-(3-6)HVNC1(E) Service Manual

8 Troubleshooting
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Checking procedure for the compressor
CHECK LIST ON COMPRESSOR
Client:
Serie number:
No. Check item
1 Is THM9 correctly connected?
THM9: Discharge Gas Thermistor
2 Is thermistor THM9 disconnected?
3 Is current sensor faulty?
4 Is current sensing part on PCB2
faulty?
5 Is the direction of current sensor
CTU, CTV) reverse?
6 Are power source wires, U and V in-
serted correctly into current sensor?
7 Is expansion valve (MV1) correctly
connected?
8 Is expansion valve coil (MV1) cor-
rectly connected?
9 Are the refrigeration cycle and
electrical wiring system incorrectly
connected?
10 Is opening of expansion valve
completely closed (locked)?
11 Is opening of expansion valve fully
opened locked)?
12 Are the contacts for comp. magnetic
switch CMC1 faulty?
Is there any voltage abnormality
13
among L1-L2, L2-L3 and L3-L1?
Is the comp. oil acidified during
14
compressor motor burning?
316
SMGB0087 rev.0 - 12/2013
Model:
Production date:
Check method
1. Is wire of thermistor correctly connected by view-
ing?
2. Check to ensure the 7-segment indication of Td
when comp. is operating.
Td: Temperature of THM9
1. Check to ensure that thermistor on the top of
comp. is correctly mounted by viewing?
2. Check to ensure that actually measured tempera-
ture is the same as the indication during check
mode.
1. Check to ensure that indication A1 and A2 are 0
during compressor stopping.
2. Check to ensure that indication A1 and A2 are not
0 during compressor running.
Check the direction => by viewing.
Check to ensure that wires are correctly inserted
Check to ensure that MV1 to CN5A is correctly con-
nected
Check to ensure that each coil is correctly mounted on
the valve.
Check to ensure that refrigerant is flowing into indoor
units by operating one refrigerating cycle only from the
outdoor unit.
Check the following by the check mode of outdoor
units.
1. Liquid pipe temperature (TL) < Air Intake tempera-
ture (Ti) during cooling operation
2. Liquid pipe temperature (TL) > Air Intake tempera-
ture (Ti) during heating operation
Check to ensure that liquid pipe temperature is lower
than air intake temperature of stopping indoor unit
when other indoor units are operating under cooling
operation.
Check the surface of each contact (L1, L2 and L3) by
viewing.
Check to ensure that voltage imbalance is smaller
than 3%.
Please note that power source voltage must be within
380V or 220V+10%.
Check to ensure that the oil color is not black.
Date:
Checker:
Result Remarks