Test Run; Before Test Run - Mitsubishi Electric MXZ-8C48NA Manuel D'installation

8. Test run

8.1. 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.
nals.
Warning:
Insulation resistance
After installation or after the power source to the unit has been cut for an extended
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.
ance 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.
8.2. Test run
8.2.1. Using remote controller
Refer to the indoor unit installation manual.
unit operates properly following the installation manual attached to the unit.
erroneous connection, if any, of the refrigerant pipes and the connecting
wires.
* The compressor operation is not available for 3 minutes at least after the
power is supplied.
of low outside air temperature.
About the restart protective mechanism
Once the compressor stops, the restart preventive device operates so the compressor
will not operate for 3 minutes to protect the air conditioner.
Perform the following procedures to collect the refrigerant when moving the
indoor unit or the outdoor unit.
1 Turn off the circuit breaker.
2 Connect the low pressure side of the gauge manifold to the service port of the
gas side stop valve.
3 Close the liquid stop valve.
4 Supply power (circuit breaker).
* Start-up of the indoor-outdoor communication takes about 3 minutes after the
power (circuit breaker) is turned on. Start the pump-down operation 3 to 4
5
test run for cooling operation. The compressor (outdoor unit) and ventilators
(indoor and outdoor units) start operating and test run for cooling operation
begins. Immediately after performing the test run for cooling operation, set the
Make sure to switch it to OFF after pump down is completed.
16
warmed up for four hours.
(The time necessary to warm up the compressor varies according to atmos-
pheric conditions and refrigerant accumulation.)
-
the compressor must be warmed up at least 12 hours to prevent breakdown.
Caution:
The compressor will not operate unless the power supply phase connec-
tion is correct.
-
- 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.
when the outdoor unit is faulty.
8.2.2. Using SW3 in outdoor unit
Note:
In case of the test run from outdoor unit, all indoor units operate. Therefore,
you can not detect any erroneous connection of refrigerant pipes and the
connecting wires. If it aims at detection of any erroneous connection, be
sure to carry out the test run from remote controller with reference to "8.2.1.
Using remote controller".
SW3-1 ON
Cooling operation
SW3-2 OFF
SW3-1 ON
Heating operation
SW3-2 ON
* After performing the test run, set SW3-1 to OFF.
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 SW3-2 during
the test run by DIP switch SW3-1. After changing the test run operation mode,
resume the test run by switch SW3-1.)
6 Fully close the gas stop valve when the pressure reading on the gauge drops
7.1 - 0.0 PSIG (approximately 0.5 - 0.0 kgf/cm
7 Set SW3-1 to OFF to stop the air conditioner operation. (Set the outdoor ser-
8 Turn off the power supply (circuit breaker).
* If too much refrigerant has been added to the air conditioner system, the
pressure may not drop to 7.1 PSIG (0.5 kgf/cm
ant collecting device to collect all of the refrigerant in the system, and then
recharge the system with the correct amount of refrigerant after the indoor and
outdoor units have been relocated.
Warning:
When pumping down the refrigerant, stop the compressor before discon-
necting the refrigerant pipes. The compressor may burst and cause injury if
any foreign substance, such as air, enters the system.
2 )
2 ). If this occurs, use a refriger-