3
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2WAY SYSTEM
Outdoor Unit Repair Procedures
3
9. Compressor
9-1. Compressor Trouble Diagnosis and Check Methods
Generally, compressor failures can be classified into the following categories.
(1) Mechanical trouble
(A) Locking (intrusion of foreign objects, galling, etc.)
(B) Pressure rise failure (damaged valve, seal, bearing, or other component)
(C) Noise (damaged stator rotor, valve, or other component)
(2) Electrical trouble
(A) Coil burning
(B)
Open
circuit
(C)
Insulation
failure
(D)
Short
circuit
Trouble diagnosis is based on the following remote controller displays: [H03] (Compressor 1: INV compressor,
cen- ter), [H11] [H12] [H13] (Compressor 2: constant-speed compressor 1, left side when viewed from front <not
present in model U-8ME1E8(E)> ), [H21] [H22] [H23] (Compressor 3: constant-speed compressor 2, right side
when viewed from front (not present in models U-8ME1E8(E), U-10ME1E8(E), U-12ME1E8(E). A judgment is
made based on factors that include the following: coil resistance (varies depending on the compressor), insulation
resistance, current, leakage breaker operation, oil and refrigerant fouling, odor, pressure, and noise.
Reference: Insulation resistance (Use a DC 500 V insulation resistance meter and measure the insulation resis-
tance between the electrified and non-electrified parts.)
(a)
Motor
Min. 300 M
(b)
Compressor
Min. 100 M (servicing part)
(c)
Unit
Min. 10 M (This is due to the presence of refrigerant, which decreases
the
insulation
resistance.)
* Minimum insulation resistance as required by generally accepted requirements is 1 M .
JUDGMENT START
Is there burning of the failed
compressor motor?
Follow the instructions in
“2. Discharging Compressor Oil” and
drain the oil from all compressors in the
same system. Then inspect.
Is the color phase 4.0 or above, or is a
sharp odor present?
Go to “9-2-1. Replacing only the
failed compressor.”
Follow the instructions in
“2. Discharging Compressor Oil”
and drain the oil from the failed
compressor. Then inspect.
Go to “9-2-3. Replacing all
compressors in a system.”
Are there 2 or more outdoor units where
the compressor oil color phase is 4.0 or
higher or where a sharp odor is
present?
Follow the instructions in “9-2-4. Dry
core cleaning” and perform dry core
cleaning of all outdoor units.
Go to “9-2-2. Replacing all
compressors in a failed unit.”
Follow the instructions in
“9-2-4. Dry core cleaning” and
perform dry core cleaning of the
failed outdoor unit.
NO
NO
NO
YES
YES
YES
Reference: Symptoms of motor burning
1. Ground fault results in breaker operation.
2. Short circuit results in different coil resistance at different phases.
3. Open circuit
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SM830186-00̲2WAY ECO-i.indb 27
2010/12/08 14:27:41
2010/12/08 14:27:41
