Instructions For Debris Removal Operation - Mitsubishi Electric CMB-WM108V-AA Service Handbook

[ VIII Troubleshooting ]

[7] Instructions for debris removal operation

This operation removes the debris that may have been introduced during installation from the water circuit.
Perform this operation after completion of water- and refrigerant-piping work, air tightness test, evacuation
of refrigerant circuits, refrigerant charging, and electrical work.
1.Preparation for debris removal operation
1.Set DIP SW 5-1 (valve opening when stopped), DIP SW 5-2 (nullification of drain over-flow error for 9 hours) from
off to on.
HBC controller
2.Turn on the breaker, and then open the air vent valves on the HBC controller and the indoor units.
Refer to the Installation Manual for the location of air vent valves.
(If there are air vent valves on the field-installed pipes, open the valves as well.)
3.Supply water from the suction pipe on the HBC controller.
4.Check that water comes from each air vent valve, and perform the debris removal operation.
2.Debris removal operation
1.If there are a large amount of debris in the water in the field-installed pipes, set DIPSW4-1 from OFF to ON.
(Refer to the flowchart for debris removal operation for details.)
Perform the debris removal operation. (Each air vent valve should stay open.)
2.Debris removal operation will be completed in 40 minutes, and the LED indication will change to "Air1," "Air2," and
"AirE" in order. Then, the water pump will stop.
3.Stop the water supply, and check that no water is coming out of the air vent valves. Then, set the dipswitch 4-1 from ON to OFF.
4.Set DIP SW4-6 to on, and switch off the HBC controller. Open the air-vent valve and the water-vent valve.
Slowly open the strainer closest to the water supply to the HBC. (Note that if it is opened fast, water may blast out.)
Remove the strainer, clean its inside, and refit it.
5.Slowly open the other strainer which is the furthest from the water supply.
(After the cleaning, set DIPSW4-6 to OFF.)
6.Make sure the strainers are re-installed.
Flowchart for debris removal operation (DIPSW4-1 is ON.)
Intermittent operation of water pump (20 min)
Step 1
Operation of all indoor units (20 min)
Step 2
( 1 ) The operation can be forced to stop by setting DIPSW4-4 from OFF to ON.
( 2 ) If it is found during any step that air ventilation has not been completed to the desired degree, start over at Step 2-1.
<General cautions>
( 1 ) To avoid malfunction, do not connect or disconnect the power connector of the water pump being powered on.
( 2 ) Check for water leaks from the field-installed pipe joint during operation.
( 3 ) Do not pull the clip on the connection of the water pipe with pliers so that undue force is applied.
( 4 ) If Error appears on the LED, turn off the breaker, turn it back on, and start over at step 2-1.
3.End processing
Set the dipswitches 5-1 and 5-2 to OFF after completion of debris removal operation.
HWE1708A
Indoor unit (Example: PEFY-WP-VMA-E)
Install a non-return valve to prevent water in the water circuit
flowing back to the water supply pipe, or remove the water
supply hose after the air vent operation.
LED and DIPSW positions
- 202 -
The operation is performed while air is
discharged from the water pipe. [Air1]
Debris in the pipe will accumulate into the
strainer by operating all indoor units. [Air2 to AirE]
GB