Check Of Compressor; Check Of Compressor Winding; Check Of Compressor Operation - Mitsubishi Electric MSC-07RV Service Manual

Check of compressor

I
Start
ICheck the compressor
winding on page 138.
Normal
J Check of compressor
operation on page 138.
Continuous
Nomal

Check of compressor winding

J
Disconnect the lead wires and check the resistance between the compressor terminals.
<Measuring points>
Measure the AC voltages at the following three points on the transistor module.
BLK - WHT
BLK - RED
WHT - RED
<Judgment>
1.05 ~ 1.29Ω (MXZ-18RV), 0.47 ~ 0.58Ω (MXZ-32RV) at -10 °C ~ 40 °C of
winding temperature.
Zero (Ω) : Faulty (Short)
Infinite (Ω) : Faulty (Open)
NOTE 1 : Be sure to zero the tester before measurement.
NOTE 2 : The winding resistance is 1.2Ω(MXZ-18RV),0.54Ω(MXZ-32RV)
at 20°C for each phase.

Check of compressor operation

K
• Connect the compressor, activate the inverter, and count time until the inverter stops due to overcurrent.
<Operating method>
Perform the test run in the cooling or heating mode by using the emergency operation switch on the indoor unit.
<Measuring point>
Count time from when the outdoor fan starts up until the inverter stops due to overcurrent.
<Judgment>
Inverter stops in 0 to 10 seconds : Faulty (Short)
Inverter stops in 10 to 60 seconds : Faulty (Compressor lock)
Inverter stops in 60 seconds to 5 minutes : Faulty (Refrigerant circuit defective)
Inverter operates for 5 minutes or more : Normal
<MXZ-18/32RV>
Short or
open
Replace the compressor
Stop J Check of compressor
operation on page 138.
more than
10 sec.
Check of refrigerant
circuit.
<MXZ-18/32RV>
<MXZ-18/32RV>
10 sec.
or less
Replace compressor
137
Tester indication
Normal
X1 (One to dozens of ohms)
Faulty
(Zero ohms or short)
X1
Faulty
(Infinite or open)
X1
0 sec. Outdoor fan start-up
10sec. Faulty (Compressor sfort or luyer-short)
Faulty (Compressor lock. etc.)
Faulty (Refrigerant circuit
60sec.
defective,etc.)
5 min.
Normal