Water Pipe Installation - Mitsubishi Electric PWFY-P100VM-E-BU Data Book

3. Water pipe installation
(1) Water circuit sample
Solid arrows in the figure indicate
the direction of water flow.
PWFY
Water-side
heat exchanger
6)
Consider the following when designing and installing a water piping system. (Items (1)-(14) in the figure are explained
below.)
1) Union joints/flange joints etc.
Install a flange etc. to allow for easy replacement of connected equipment.
2) Thermometer
For checking unit performance and operation monitoring
3) Water pressure gauge
For operation status monitoring
4) Valve
Install a valve for easy replacement and cleaning of the refrigerant flow control device.
Install a refrigerant flow control valve on the fan coil outlet side.
5) Flexible joint
Recommended to prevent the noise and vibration from the pump from being transmitted.
6) Drain pipe
Install the drain pipe with an inclination of between 1/100 and 1/200 to provide a downward flow of drain water.
For cold climate installation, take an appropriate measure (e.g., drain heater) to prevent the drain water from
freezing.
7) Pump
Use a pump that is large enough to compensate for the total water pressure loss and to supply sufficient water to the
unit.
8) Air vent valve
Provide air vent valves on the pipes.
9) Expansion tank
Install an expansion tank to accommodate expanded water and to supply water.
10) Cold/Hot water pipe
Use pipes that allow for easy air purging, and provide sufficient insulation.
11) Drain valve
Install drain valves so that water can be drained for servicing.
12) Strainer
Install a strainer near the PWFY unit to keep foreign materials from entering the water-side heat exchanger.
13) Flow switch
Install the supplied flow switch on the outlet pipe.
14) Tank
Minimum tank capacity : 100 L (Refer to Fig IV.3.(8).1)
City water
Field supply
2) 8) 3)
13)
1) 4)
T P
T P
1) 2) 11) 4) 3) 5)
12)
Sample of water circuit for PWFY
9)
1)
Overflowed water
1)
To drain outlet
Uphill gradient ≥ 1/200
14)
Tank
5)
P
5)
4) 7) 4) 3) 11)
- 49 -
Roof
8)
Tank Outlet
Inlet