Test Run; Before Test Run; Self-Check - Mitsubishi Electric MVZ-A12AA7 Installation Manual

14. Test run

14.1. Before test run

After completing installation and the wiring and piping of
the indoor and outdoor units, check for refrigerant leakage,
looseness in the power supply or control wiring, wrong polarity,
and no disconnection of one phase in the supply.
Use a 500-volt megohmmeter to check that the resistance
between the power supply terminals and ground is at least 1.0
MΩ.
Do not carry out this test on the control wiring (low voltage
circuit) terminals.
Warning:
Do not use the air conditioner if the insulation
resistance is less than 1.0 MΩ.
After installation or after the power source to the unit has been cut
for an extended period, the insulation resistance will drop below 1
MΩ due to refrigerant accumulating in the compressor. This is not a
malfunction. Perform the following procedures.
1. Remove the wires from the compressor and measure the
insulation resistance of the compressor.
2. If the insulation resistance is below 1 MΩ, the compressor is faulty
or the resistance dropped due the accumulation of refrigerant in the
compressor.
3. After connecting the wires to the compressor, the compressor will
start to warm up after power is supplied. After supplying power for
the times indicated below, measure the insulation resistance again.
14.2. Test run
Refer to the installation manual that comes with each remote controller for details.

14.3. Self-check

Refer to the installation manual that comes with each remote controller for details.
RF thermostat is not established.
[Output pattern A] Errors detected by indoor unit
IR wireless remote controller
Beeper sounds/OPERATION
INDICATOR lamp flashes
(Number of times)
1
2
3
4
5
6
7
8
9
10
11
12
No sound
26
Wired remote controller
RF thermostat
Check code
P1 Intake sensor error
P2, P9 Pipe (Liquid or 2-phase pipe) sensor error
E6, E7 Indoor/outdoor unit communication error
P4 Drain sensor error
P5 Drain pump error
P6 Freezing/Overheating safeguard operation
EE Communication error between indoor and outdoor units
P8 Pipe temperature error
E4 Remote controller signal receiving error
– –
– –
Fb Indoor unit control system error (memory error, etc.)
– – No corresponding
• The insulation resistance drops due to accumulation of refrigerant
in the compressor. The resistance will rise above 1 MΩ after the
compressor is warmed up for two to three hours.
(The time necessary to warm up the compressor varies according to
atmospheric conditions and refrigerant accumulation.)
• To operate the compressor with refrigerant accumulated in the
compressor, the compressor must be warmed up at least 12 hours to
prevent breakdown.
4. If the insulation resistance rises above 1 MΩ, the compressor is
not faulty.
Caution:
The compressor will not operate unless the power
•
supply phase connection is correct.
• Turn on the power at least 12 hours before starting
operation.
− Starting operation immediately after turning on the main
power switch can result in severe damage to internal parts.
Keep the power switch turned on during the operational
season.
Symptom Remark