Test Run By Outdoor Unit Sw4; Using Sw4 In Outdoor Unit - Mitsubishi Electric MXZ-8A140VA Technical & Service Manual

(2) Using SW4 in outdoor unit

In case of the test run from outdoor unit, all indoor units operate. Therefore, you cannot detect any erroneous con-
nection 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 "(1) Using remote controller."
SW4-1 ON
SW4-2 OFF
SW4-1 ON
SW4-2 ON
w After performing the test run, set SW4-1 to OFF.
• 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.
When a test run is started by "Using SW4 in outdoor unit", even if it carries out stop instructions by
remote controller, outdoor unit does not stop. A test run is not ended.
In this case, please set SW4 in outdoor unit to off.
• After power is supplied or after an operation stop for a while, a small clicking noise may be heard from the inside
of the branch box. The electronic expansion valve is opening and closing. The unit is not faulty.
NOTE:Be sure to wait at least 3 minutes after turning on the power supply before setting SW4-1and SW4-2.
If the DIP switches are set before 3 minutes has elapsed, the test run may not start.

9-2-3. Test run by outdoor unit SW4

The setting of test run (ON/OFF) and its operation mode (cooling/heating) can be set by SW4 on the controller board of out-
door unit.
1Set operation mode(cooling or heating) by SW4-2.
2Start test run by setting SW4-1 to ON (
3Finish test run by setting SW4-1 to OFF (
• Operation mode cannot be changed by SW4-2 during test run.
Stop test run to change operation mode by SW4-1, and restart test run by SW4-1 after
the mode is changed.
• Test run automatically stops 2 hours later by 2-hour OFF timer function.
• Test run can be performed by the remote controller.
• The remote controller display of test run by outdoor unit is the same as that of test run by
remote controller.
• If test run is set with the outdoor unit, the test run is performed for all indoor units.
• The remote controller operation becomes unavailable once the test run is set with the outdoor unit.
During the test run set with the outdoor unit, operation on/off or operation mode change cannot be performed by the remote
controller, and the operation relating to the test run which is made with the outdoor unit will be prior to any other commands
from the remote controller. Set the SW4-1 to OFF (
Emergency operation is not available for this model.
Cooling operation
Heating operation
) with the indicated operation mode of SW4-2.
).
) to finish test run.
42
(Initial setting)
SW4
C D
A Stop
ON
B Cooling
C Operation
D Heating
1 2
A B