Mitsubishi Electric City Multi PURY-EM200YNW-A1, Service Handbook

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[8-14 HBC Maintenance Instructions (Applicable to main and sub HBCs) ]
BS_08_L chapter 8 -
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8-14-3 Instructions for the Air Vent Operation
This operation removes the air from the water circuit after water is supplied to it.
Perform this operation after completion of the following.
*1
• Water piping work *2
• Air-tightness test of water piping
• Electrical work
• Refrigerant piping work
*3
• Air-tightness test of refrigerant piping *3
• Evacuation of refrigerant circuits
*3
• Refrigerant charging *3
*1. Perform air vent operation after completion of water- and refrigerant-piping work,
air-tightness tests, electrical work, evacuation of refrigerant circuits, refrigerant
charging, and debris removal operation (shown on previous pages).
*2. Install an automatic air vent valve at the highest point of each branch pipe from the HBC (in two places at the highest point of the
return pipe from the Sub-HBC, and in six places at the highest point of the return pipes from indoor units). (See Figure 1.)
Failure to install air vent valves may leave air in the water circuit and damage the pump.
*3. Air vent operation can be performed before completing the refrigerant piping work, air-tightness test of refrigerant piping, evacuation of
refrigerant circuits, and refrigerant charging.
In this case,
perform an air vent operation again after refrigerant piping work, air-tightness test of refrigerant piping, evacuation of
refrigerant circuits, and refrigerant charging have been completed, because the initial air vent operation may not be able to remove all
dissolved oxygen in the water circuit.
1. Preparation for air vent operation
1. DIP SW settings
[Main-HBC]
Turn on DIP SW001-1. (Water circuit valve setting (valve open when stopped))
2. Turn on the breaker for each unit, and then open the manual air vent valves on the Sub-HBC and the indoor units. (The Main-HBC does not
have an manual air vent valve.)
*
Maintenance-side
Maintenance-side
3. Supply water from the water supply pipe on the HBC.
Water supply pipe
water supply pipe, or remove the water supply hose after the air vent operation.
Connection of water supply pipe
4. Check that water is coming out of the manual air vent valve on each unit, and perform the air vent operation.
Figure 1. Automatic air vent valve
Automatic air vent
valve
Manual air
vent valve
SW001-2.
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