Test Run - Mitsubishi Electric PUHZ-W85VHA Installation Manual

6. Electrical work
6.2. Field electrical wiring
Outdoor unit power supply
Outdoor unit Circuit Breaker capacity
Outdoor unit power supply, earth
Interface unit/Flow temp. controller-Outdoor unit
Interface unit/Flow temp. controller-Outdoor unit earth
Remote controller-Interface unit/Flow temp. controller
Outdoor unit L-N (single)
Interface unit/Flow temp. controller-Outdoor unit S1-S2
Interface unit/Flow temp. controller-Outdoor unit S2-S3
Remote controller-Interface unit/Flow temp. controller
*1. A breaker with at least 3.0 mm contact separation in each pole shall be provided. Use earth leakage breaker (NV).
*2. Max. 80 m
*3. The fi gures are NOT always against the ground.
S3 terminal has DC 24 V against S2 terminal. However between S3 and S1, these terminals are NOT electrically insulated by the transformer or other device.
Notes: 1. Wiring size must comply with the applicable local and national codes.
2. Power supply cables and the cables between Interface unit/Flow temp. controller and outdoor unit shall not be lighter than polychloroprene sheathed
fl exible cables. (Design 60245 IEC 57)
3. Be sure to connect the cables between Interface unit/Flow temp. controller and outdoor unit directly to the units (no intermediate connections are al-
lowed).
Intermediate connections may result in communication errors. If water enters at the intermediate connection point, it may cause insuffi cient insula-
tion to ground or a poor electrical contact .
(If an intermediate connection is necessary, be sure to take measures to prevent water from entering the cables.)
4. Install an earth longer than other cables.
Warning:
In case of A-control wiring, there is high voltage potential on the S3 terminal caused by electrical circuit design that has no electrical insulation between power
line and communication signal line. Therefore, please turn off the main power supply when servicing. And do not touch the S1, S2, S3 terminals when the power
is energized. If isolator should be used between indoor unit and outdoor unit, please use 3-pole type.

7. Test run

Before test run
► After installation works are completed, check if there is no refrigerant leak-
age, no looseness in the power supply or control wiring, no 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 1.0MΩ.
Warning:
Do not use the air to water heat pump if the insulation resistance is less than
1.0MΩ.
Insulation resistance
When installed the power source to the unit has been cut for an extended period,
the insulation resistance may drop below 1 MΩ due to the accumulation of refriger-
ant within the compressor. This is not a malfunction. Perform the following proce-
dures.
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 may be faulty or sim-
ply the accumulation of refrigerant in the compressor makes the resistance drop.
6
*1
*2
*2
*3
*3
*3
*3
230V
Single phase
Isolator
S1
Outdoor Unit S2
S3
~/N (single), 50 Hz, 230 V
25 A
3 × Min. 4
3 × 1.5 (polar)
1 × Min. 1.5
2 × 0.3 (Non-polar)
AC 230 V
AC 230 V
DC 24 V
DC 12 V
3 poles isolator
3. After connecting the wires to the compressor, the compressor starts to warm
up once power is supplied. After supplying power for the times indicated below,
measure the insulation resistance again.
• The insulation resistance drops due to the accumulation of refrigerant in the
compressor. The resistance will rise above 1 MΩ after the compressor is
warmed up for four hours.
(The necessary time to warm up the compressor varies according to atmo-
spheric conditions and refrigerant accumulation.)
• If the refrigerant accumulates within the compressor, the compressor must be
warmed up at least 12 hours before starting the operation to prevent break-
down.
4. If the insulation resistance rises above 1 MΩ, the compressor is not faulty.
Caution:
• The compressor does not operate if the power supply phase connection is
incorrect.
• 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
operating period.
S1
Interface unit /
S2
Flow temp.
controller
S3