Drain Piping Work; Connecting Water Pipework; Important Notes On Water Pipework Installation; Water Pipe Insulation - Mitsubishi Electric CITY MULTI CMB-WM1016V-AB Installationshandbuch

4.5. Drain piping work

1. Drain piping work
• Ensure that the drain piping is downward (sloped gradient of more than 1/100) to
the outdoor (discharge) side. If it is impossible to take any downward pitch, use
an optionally available drain-up mechanism to obtain a downward pitch of more
than 1/100.
• Ensure that any cross-wise drain piping is less than 20 m. If the drain piping is
long, support it with metal brackets to prevent it from bending, warping, or
vibrating.
• Connect the supplied drain hose to the discharge port on the unit body. Use hard
vinyl chloride pipes VP-25 (ø32) for drain piping (2). Tighten the supplied drain
hose onto the discharge port using the supplied hose band. (For this, do not use
any adhesive because the drain hose will need to be removed for servicing at a
later date.)
• Do not use any odor trap around the discharge port.
[Fig. 4.4.1] (P.4)
A: 25 cm
A Downward gradient of more than 1/100
B Insulating material
D Drain discharge port
F Cable tie (accessory)

5. Connecting water pipework

Please observe the following precautions during installation.
5.1. Important notes on water pipework
installation
• The design pressure of the HBC water system is 0.6MPa.
• Use water pipe-work with a design pressure of at least 1.0MPa.
• When performing a water leak check, please do not allow the water pressure to
go above 0.3MPa.
• Perform a pressure test on the field-installed water pipes at a pressure equal to
1.5 times the design pressure. Before performing a pressure test, isolate the
pipes from HBC and indoor units.
• 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.
• Use the reverse-return method to insure proper pipe resistance to each unit.
• Provide some joints and valves 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 especially when connecting the
HBC controller and the Sub-HBC controller.
(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 (clock-
wise), 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 spanner when installing the pipes or
strainer. Tighten screws to a torque of 40 N·m.
• 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.
• Please use copper or plastic pipes for the water circuit. Do not use steel or
stainless steel pipework. Furthermore, when using copper pipe-work, use a non-
oxidative brazing method. Oxidation of the pipe-work will reduce the pump life.
• Add water pressure gauge to see if the water pressure in HBC is correct or not.
• Be sure to braze the water pipes after covering a wet cloth to the insulation
pipes of the units in order to prevent them from burning and shrinking by
heat. (There are some plastic parts in HBC.)
• Install the unit so that external force is not applied to the water pipes.
• After filling the pipes with water, immediately perform debris removal
operation and air vent operation.
B: 1.5 – 2 m
C Supporting bracket
E Drain hose (200 mm long, accessory)
G Hose band (accessory)
• As shown in 3, install a collecting pipe about 10 cm below the drain ports and
give it a downward pitch of more than 1/100. This collecting pipe should be of VP-
30.
• Set the end of drain piping in a place without any risk of odor generation.
• Do not put the end of drain piping into any drain where ionic gases are
generated.
• Drain piping may be installed in any direction. However, please be sure to
observe the above instructions.
[Fig. 4.4.2] (P.4)
A Main-HBC controller/Sub-HBC controller
B Indoor unit
D Please ensure this length is at least 100 mm.
2. Discharge test
After completing drain piping work, open the HBC controller panel, and test drain
discharge using a small amount of water. Also, check to see that there is no water
leakage from the connections.
3. Insulating drain pipes
Provide sufficient insulation to the drain pipes just as for refrigerant pipes.
Caution:
Be sure to provide drain piping with heat insulation in order to prevent excess
condensation. Without drain piping, water may leak from the unit causing
damage to your property.
Example of HBC controller installation
[Fig. 5.1.1] (P.4)
A Expansion vessel (field supply)
C Strainer (field supply)
E Water inlet
G Drain pipe
I Check valve (field supply)
Note:
*1. Connect the pipes to the water pipes according to the local regulations.
[Fig. 5.1.2] (P.4)
A Indoor unit connection
C Cut the piping at the cutting point
E Field pipe
G Indoor unit and Sub-HBC connecting port
H Water inlet (EXP. VESSEL)
Note:
• Remove burr after cutting the piping to prevent entering the pipe
connection.
Check that there is no crack at the edge of the piping.
[Fig. 5.1.3] (P.5)
A HBC controller
C To Sub-HBC controller (Hot water)
E To Sub-HBC controller (Cold water)

5.2. Water pipe insulation

1. Connect the water pipes of each indoor unit to the same (correct) end connection
numbers as indicated on the indoor unit connection section of each HBC controller.
If connected to wrong end connection numbers, there will be no normal operation.
2. List indoor unit model names in the name plate on the HBC controller control box
(for identification purposes), and HBC controller end connection numbers and
address numbers in the name plate on the indoor unit side.
In case of using cover caps for unused end connections, please use dezincifica-
tion resistant brass (DZR) (field supply). Not using the rubber end caps will lead
to water leakage.
3. Be sure to add insulation work to water piping by covering water pipework sepa-
rately with enough thickness heat-resistant polyethylene, so that no gap is
observed in the joint between indoor unit and insulating material, and insulating
materials themselves. When insulation work is insufficient, there is a possibility of
condensation, etc. Pay special attention to insulation work in the ceiling plenum.
[Fig. 5.2.1] (P.5)
A Locally procured insulating material for pipes
B Bind here using band or tape.
D Lap margin: more than 40 mm
F Unit side insulating material
• Insulation materials for the pipes to be added on site must meet the following
specifications:
HBC controller
20 mm or more
-indoor unit
HBC controller
20 mm or more
-Sub-HBC controller
• This specification is based on copper for water piping. When using plastic
pipework, choose a thickness based on the plastic pipe performance.
C Collecting pipe
B Shutoff valve (field supply)
D Pressure reducing valve (field supply)
F Refrigerant pipes
H Pressure gauge (field supply)
B Cutting point
D Field pipe connection (field supply)
F Pipe connection (field supply)
B Sub-HBC controller
D From Sub-HBC controller (Hot water)
F From Sub-HBC controller (Cold water)
C Do not leave any opening.
E Insulating material (field supply)
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