Confirming Drain Discharge; Connecting Water Pipes; Important Notes On Water Pipework Installation; Water Pipe Insulation - Mitsubishi Electric CITY MULTI Série Manuel D'installation

6.4. Confirming drain discharge

u Make sure that the drain-up mechanism operates normally for dis-
charge and that there is no water leakage from the connections.
• Be sure to confirm the above in a period of heating operation.
• Be sure to confirm the above before ceiling work is done in the case of a new
construction.
1. Remove the water supply port cover on the same side as the indoor unit piping.
2. Fill water into the feed water pump using a feed water tank. In filling, be sure
to put the end of the pump or tank in a drain pan. (If the insertion is incom-
plete, water may flow over the machine.)
3. Perform the test run in cooling mode, or connect the connector to the ON
side of SWE on the Indoor controller board. (The drain pump and the fan are
forced to operate without any remote controller operation.) Make sure using
a transparent hose that drain is discharged.
SWE
Connector
OFF ON OFF
<OFF>

7. Connecting water pipes

Please observe the following precautions during installation.
7.1. Important notes on water pipework
installation
• The water pressure resistance of the water pipes in the heat source unit is
1.0MPa [145psi].
• 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 address-
es 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 main-
tenance, 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 ap-
pear 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 wa-
ter flow is stopped on low ambient, drain the water out.
• The unused knockout holes should be closed and the refrigerant pipes, wa-
ter 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 spanner when installing the
pipes or strainer. Tighten the screws according to the table below.
PEFY-WP-VMA-E Torque [N·m]
WP20, 25, 30, 40, 50
WP63, 71, 80, 100, 125
• 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, ap-
ply liquid sealing material for water piping over the sealing tape before con-
nection.
• 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.
12
SWE
ON
<ON>
40
60
4. After confirmation, cancel the test run mode, and turn off the main power. If
the connector is connected to the ON side of SWE, disconnect it and connect
it to the OFF side, and attach the water supply port cover into its original posi-
tion.
SWE
Connector
OFF ON OFF
<ON>
[Fig. 6.4.1] (P.5)
A Insert pump's end 2 to 4 cm.
B Remove the water supply port.
C About 2500 cc
D Water
E Filling port
F Screw
[Fig. 6.4.2] (P.5)
<Indoor controller board>

7.2. Water pipe insulation

1. Connect the water pipes of each indoor unit to the same (correct) end connec-
tion 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 num-
bers and address numbers in the name plate on the indoor unit side.
Seal unused end connections using cover caps (sold separately). Not replac-
ing on end cap will lead to water leakage.
3. Be sure to add insulation work to water piping by covering water pipework
separately with enough thickness heat-resistant polyethylene, so that no gap
is observed in the joint between indoor unit and insulating material, and in-
sulating 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. 7.2.1] (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
[Fig. 7.2.2] (P.5)
A Water pipe: To HBC unit
• Insulation materials for the pipes to be added on site must meet the following
specifications:
HBC controller
20 mm or more
-indoor unit
• This specification is based on copper for water piping. When using plastic
pipework, choose a thickness based on the plastic pipe performance.
• Installation of pipes in a high-temperature high-humidity environment, such
as the top floor of a building, may require the use of insulation materials
thicker than the ones specified in the chart above.
• When certain specifications presented by the client must be met, ensure that
they also meet the specifications on the chart above.
4. Expansion tank
Install an expansion tank to accommodate expanded water. (circuit protec-
tion valve set pressure: 600kPa)
Expansion tank selection criteria:
• The water containment volume of the HBC.
• The maximum water temperature is 60°C.
• The minimum water temperature is 5°C.
• The circuit protection valve set pressure is 370-490kPa.
• The circulation pump head pressure is 0.24MPa.
5. Leakproof the water pipework, valves and drain pipework. Leakproof all the
way to, and include pipe ends so that condensation cannot enter the insu-
lated pipework.
6. Apply caulking around the ends of the insulation to prevent condensation
getting between the pipework and insulation.
7. Add a drain valve so that the unit and pipework can be drained.
8. Ensure there are no gaps in the pipework insulation. Insulate the pipework
right up to the unit.
9. Ensure that the gradient of the drain pan pipework is such that discharge can
only blow out.
SWE
ON
<OFF>
C Do not leave any opening.
E Insulating material (field supply)
B Water pipe: From HBC unit