Precautions During Installation; Insulation Installation; Water Processing And Water Quality Control - Mitsubishi Electric City Multi PWFY-P36NMU-E-BU Manuel D'installation

Model Water inlet
PWFY-P36NMU-E-BU PT 3/4 Screw
PWFY-P36NMU-E2-AU PT 3/4 Screw
PWFY-P72NMU-E2-AU
*1 When the attached
PT 1 Screw*1
expansion joints are
installed.

7.1. Precautions during installation

heat source unit, a strainer on the circulating water inlet is necessary.)
pipe, be sure to vent the excess air.
unit. Use a drainage pipe connected to the drain valve at the base of the unit
to drain the water.
vent excess vibration.
construction)
①
and do not let the tape run over the edge.
② Overlap the sealing tape by two-thirds to three-fourths of its width on
against each thread.
③ Leave the 1.5th through 2nd farthest threads away from the pipe end
unwrapped.
pipes or strainer. Tighten screws to a torque of 50 N . m.
the water pipes with insulating materials to prevent burns.
at the inlet after installing the strainer, and outlet.
Example of unit installation (using light piping)
[Fig. 7.1.1] [Fig. 7.1.2] (P.2)
Ⓐ Close valve
Ⓒ Water outlet
Ⓔ Y-type strainer
Ⓖ Expansion joint
water circuit parts such as those shown in [Fig. 7.1.3] and [Fig. 7.1.4].
Single system sample
[Fig. 7.1.3] (P.3)
Multiple system sample
[Fig. 7.1.4] (P.3)
1 PWFY-P36/72NMU-E2-AU or PWFY-P36NMU-E-BU
2 Strainer
3 Flow Switch (PWFY-P36/72NMU-E2-AU ONLY)
*1
4 Shut off valve
*1
5 Temperature gauge
*1
6 Pressure gauge
*1
7 Deaerator (Air separator)
*1
8 Air vent
*1
9 Safety valve
*1
0
*1 *2
a Buffer vessel (if necessary)
*1
b Drain valve
*1
c
10
Water outlet
PT 3/4 Screw
PT 3/4 Screw
PT 1 Screw*1
-
Ⓑ Water inlet
Ⓓ Refrigerant piping
Ⓕ Drain pipe
*3
*1
d Antivibration sleeve
*1
e Fix speed pump
*1
f Dirt separator (if necessary)
g
*2 Water volume (= a + g ) is complied with Fig.7.1.5 per
PWFY-P36/72NMU-E2-AU
Ⓐ Primary
Ⓒ Water Supply
Note:
reference, and Mitsubishi Electric Corporation shall not be held responsible for
any problems arising from the use of this circuit.
[Fig. 7.1.5] (P.4)
Ⓐ Water volume limitation [L]
Ⓒ Available water volume area

7.2. Insulation installation

The surface temperature of the water pipe would be very high, depending on the
set temperature. Insulate the pipe to prevent burns. When operating PWFY-P36/
P72NMU-E2-AU with cold water, insulate the water pipe to prevent condensa-
tion.
Wrap insulation material around water pipes as shown in [Fig. 7.2.1].
[Fig. 7.2.1] (P.4)
Ⓐ Heat insulation material (accessory)
Ⓑ
7.3. Water processing and water quality
control
To preserve water quality, use the closed type of cooling tower for unit. When the
circulating water quality is poor, the water heat exchanger can develop scales,
leading to a reduction in heat-exchange power and possible corrosion of the
heat exchanger. Please pay careful attention to water processing and water
quality control when installing the water circulation system.
During installation, be careful that foreign objects, such as welding frag-
ments, sealant particles, or rust, do not enter the pipes.
① Depending on the quality of the cold-temperature water used in the air-
conditioner, the copper piping of the heat exchanger may become cor-
roded. We recommend regular water quality processing.
ticularly prone to corrosion.
exchanger, and use a closed-loop circuit on the air conditioner side. If a
*1 *2
Ⓑ 2ndary (Depend on site)
Ⓑ Total hardness [mg/L]
-
ℓ.