Test Run; Before Test Run - Mitsubishi Electric Mr. Slim PUHZ-P-YHA Serie Manual De Instalación

6. Electrical work
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.
WIRING SPECIFICATIONS FOR 220-240 V 50 Hz
(INDOOR-OUTDOOR CONNECTING CABLE)
Cross section of cable Wire size (mm²)
Round
2.5
Flat
2.5
Flat
1.5
Round
2.5
*1 : Power supply cords of appliances shall not be lighter than design 60245 IEC or 227 IEC.
*2 : In case that cable with stripe of yellow and green is available.
*3 : In case of regular polarity connection (S1-S2-S3), wire size is 1.5 mm².
*4 : In case of regular polarity connection (S1-S2-S3).
*5 : In the fl at cables are connected as this picture, they can be used up to 30 m.
Be sure to connect the indoor-outdoor connecting cables directly to the units (no intermediate connections).
Intermediate connections can lead to communication errors if water enters the cables and causes insuffi cient insulation to ground or a poor electrical con-
tact at the intermediate connection point.

7. Test run

7.1. 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 sup-
ply 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 1.0M".
Do not carry out this test on the control wiring (low voltage circuit) termi-
nals.
Warning:
Do not use the air conditioner if the insulation resistance is less than 1.0M".
Insulation resistance
After installation or after the power source to the unit has been cut for an extended
period, the insulation resistance will drop below 1 M" due to refrigerant accumulat-
ing 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 M", the compressor is faulty or the resis-
tance 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.
7.2. Test run
7.2.1. Using SW4 in outdoor unit
SW4-1 ON
Cooling operation
SW4-2 OFF
SW4-1 ON
Heating operation
SW4-2 ON
* After performing the test run, set SW4-1 to OFF.
• After power is supplied, a small clicking noise may be heard from the inside of
the outdoor unit. The electronic expansion valve is opening and closing. The unit
is not faulty.
Power supply
Isolator
S1
A-Control
S2
Outdoor Unit
S3
Number of wires
Clockwise : S1-S2-S3
3
* Pay attention to stripe of yellow and green
Not applicable
3
(Because center wire has no cover fi nish)
4 From left to right : S1-Open-S2-S3
Clockwise : S1-S2-S3-Open
4
*Connect S1 and S3 to the opposite angle
3 pole isolator
S1
S2
S3
Polarity L (m)*6
(30)
*2
Not applicable
*5
(18)
*3
(30)
*4
*6 : Mentioned cable length is just a reference value.
It may be different depending on the condition of installa-
tion, Humidity or materials, etc.
• The insulation resistance drops due to accumulation of refrigerant in the com-
pressor. The resistance will rise above 1 M" after the compressor is warmed
up for 4 hours.
(The time necessary to warm up the compressor varies according to atmo-
spheric 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 M", the compressor is not faulty.
Caution:
• The compressor will not operate unless the power supply phase connec-
tion 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.
The followings must be checked as well.
• The outdoor unit is not faulty. LED1 and LED2 on the control board of the out-
door unit fl ash when the outdoor unit is faulty.
• Both the gas and liquid stop valves are completely open.
• A protective sheet covers the surface of the DIP switch panel on the control
board of the outdoor unit. Remove the protective sheet to operate the DIP
switches easily.
• A few seconds after the compressor starts, a clanging noise may be heard from
the inside of the outdoor unit. The noise is coming from the check valve due to
the small difference in pressure in the pipes. The unit is not faulty.
The test run operation mode cannot be changed by DIP switch SW4-2 during
the test run. (To change the test run operation mode during the test run, stop
the test run by DIP switch SW4-1. After changing the test run operation mode,
resume the test run by switch SW4-1.)
7.2.2. Using remote controller
Refer to the indoor unit installation manual.
A-Control
Indoor Unit
(3C Flat cable × 2)
9