Before Test Run; Initial Settings For Refrigerant Leakage Detection Function - Mitsubishi Electric Mr.SLIM PUHZ-ZRP HA Série Manuel D'installation

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 MΩ.
► 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 MΩ.
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.

8. Initial settings for refrigerant leakage detection function

Remote control button positions
A C B
D
Operation mode Compressor information Outdoor unit information Indoor unit information
Activate/cancel maintenance mode
Fig. 8-1
Refrigerant
[Display ]
A
leakage detection
(initial teaching)
GAS LEAK
TEST START
[Display ] Waiting for stabilization
D
Fig. 8-3
Confirm
Refrigerant leakage
detection judgment
GAS LEAK
Fig. 8-2
JUDGE
Stabilized
After 45 minutes
• 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 four 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 flash 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.
Note : Occasionally, vapor that is made by the defrost operation may seem
as if smoke come up from the outdoor unit.
This air conditioner (outdoor unit) can detect refrigerant leakage which may happen
during a long period of use. In order to enable the leakage detection, the following
settings are required to let the unit memorize the initial conditions (initial learning).
Caution:
Make sure to perform the "7. Test run" and confirm the unit works without
any problems, before starting the following settings.
► How to select the "Refrigerant Leakage Detection" mode
Detection is possible regardless the unit's operation (ON or OFF).
Press button for more than three seconds to switch to the maintenance
TEST
mode.
[Display ]
A
MAINTENANCE
► How to start the initial learning
Press CLOCK button and select the [GAS LEAK TEST START] (Fig. 8-2)
* The initial learning for the leakage detection is always done once after the new
installation or the data reset.
Press ( ) button to confirm. (Fig. 8-3)
FILTER
How to finish the initial learning
Once the unit's operation is stabilized, the initial learning is completed.
Press button for more than three seconds to cancel the initial learning.
TEST
The initial learning can also be cancelled by pressing
* Refer to the Technical Manual for the refrigerant leakage detection judgment method.
button.
ON/OFF
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