Connecting Water Pipes; Note - Mitsubishi Electric CITY MULTI PKFY-WL NKMU-E Series Installation Manual

4. Connecting water pipes

4.1. Connecting pipes
• When commercially available copper pipes are used, wrap water pipes with
commercially available insulation materials (heat-resistant to 100 °C, 212 °F or
more, thickness of 20 mm, 25/32 inch or more).
• The indoor parts of the drain pipe should be wrapped with polyethylene foam
insulation materials (specific gravity of 0.03, thickness of 9 mm, 23/64 inch or
more).
• Use water piping insulation provided to insulate indoor unit connections. Insulate
carefully.
Warning:
When installing the unit, securely connect the water pipes before starting the
compressor.
Please observe the following precautions during installation.
4.1.1. Important notes on water pipework installation for connection
with HBC unit
• The water pressure resistance of the water pipes in the heat source unit is 1.0
MPa [145 psi].
• Please connect the water pipework of each indoor unit to the connect port on the
HBC. Failure to do so will result in incorrect running.
• Please list the indoor units on the naming plate in the HBC unit with addresses
and end connection numbers.
• If the number of indoor units are less than the number of ports on the HBC, the
unused ports can be capped. Without a cap, water will leak.
• Use the reverse-return method to insure proper pipe resistance to each unit.
• Provide some joints and bulbs around inlet/outlet of each unit for easy
maintenance, checkup, and replacement.
• Install a suitable air vent on the water pipe. After flowing water through the pipe,
vent any excess air.
• Secure the pipes with metal fitting, positioning them in locations to protect pipes
against breakage and bending.
• Do not confuse the water intake and outlet piping. Error code 5102 will appear
on the remote controller if a test run is performed with the pipe-work installed
incorrectly (inlet connected to outlet and vice versa).
• This unit doesn't include a heater to prevent freezing within tubes. If the water
flow is stopped on low ambient, drain the water out.
• The unused knockout holes should be closed and the refrigerant pipes, water
pipes, power source and transmission wires access holes should be filled with
putty.
• Install water pipe so that the water flow rate will be maintained.
• Wrap sealing tape as follows.
1 Wrap the joint with sealing tape following the direction of the threads
(clockwise), do not wrap the tape over the edge.
2 Overlap the sealing tape by two-thirds to three-fourths of its width on each
turn. Press the tape with your fingers so that it is tight against each thread.
3 Do not wrap the 1.5th through 2nd farthest threads away from the pipe end.
• Hold the pipe on the unit side in place with a wrench when installing the pipes or
strainer. Tighten screws to a torque of 40 N·m, 30 ft·bls.
• If there is a risk of freezing, carry out a procedure to prevent it.
• When connecting heat source unit water piping and on site water piping, apply
liquid sealing material for water piping over the sealing tape before connection.
• Do not use steel pipes as water pipes.
- Copper pipes are recommended.
• Install a strainer (40 mesh or more) on the pipe next to the valve to remove the
foreign matters.
• Be sure to provide anti-dew condensation treatment on the inlet and outlet of
the water pipes and on the valve. Provide an appropriate treatment on the end
surface of the dew proofing material to keep condensation out.
• When water has been supplied to the water pipework, purge the system of
air. The details of air purging can be found separately in the water circuit
maintenance manual.
• Install the unit so that external force is not applied to the water pipes.
en
6

Note:

• Use caution not to mix up the water inlet and outlet.
• Install a coupling valve on the pipe to allow access for maintenance.
• Install a flexible joint on the pipe to keep the vibration of the unit from being
transmitted to the pipe.
• Connect the pipes to the water pipes according to the local regulations.
• The piping connection of the indoor unit shall be made with CALEFFI 900 series
to prevent the indoor unit from falling.
B
A
D
A A Locally procured pipe insulation
B Tighten this location with a band (procured locally)
C Do not separate from the opening
D Wrap overlap: 40 mm, 1-37/64 inch or more
E Insulation material (procured locally)
F Unit side insulation material
G Depending on the selected joint, there may be a gap between the unit side pipe cover and
the joint.
If there is a gap, fill in the gap with the pipe covers prepared on-site.
H Compression fitting: CALEFFI 900 series (procured locally)
A
B
A Water pipe Inlet: From HBC/hydrounit
B Water pipe Outlet: To HBC
Fig. 4-2
C
H
F
E
G
Fig. 4-1