Mitsubishi Electric CMB-WM108V-AA Service Handbook page 68

[ II Restrictions ]
Fig. B
1) To connect multiple indoor units to a port
Maximum total capacity of connected indoor units: W/WP/WL80
Maximum number of connectable indoor units: 3 units
Branch joints are field-supplied.
All the indoor units that are connected to the same port must be in the same group and perform the Thermo-ON/OFF operation
simultaneously.
The room temperatures of all the indoor units in the group need to be monitored via the connected remote controller.
When connecting a W/WP/WL71 through 125 model indoor unit to an HBC controller, the pipes that connect the unit to the
same set of HBC controller ports cannot be branched out to connect additional units.
Selection of water piping
Select the size according to the total capacity of indoor units to be installed downstream.
Do not connect multiple indoor units to the same port when operating each of them in different modes (cooling, heating, stop,
and thermo-OFF). The indoor units connected to the same port must be set to operate in the same mode. Set them to the
same group to make them run/stop in the same mode all together. Alternatively, enable the thermo setting on the remote con-
troller, or set the common thermostat (optional) to run/stop the units in the same mode based on the representative tempera-
ture.
When multiple indoor units are connected to a single port, install a pressure control valve in the pipe to equalize the pressure
of all indoor units.
Pressure control valves are required for the "WP-type" and "WL-type without the optional valve kit" indoor units only, and not
for the "W-type" and "WL-type with the optional valve kit" indoor units.
2) Connecting W/WP/WL100 or 125 indoor units to an HBC controller
When connecting W/WP/WL100 or 125 indoor units to an HBC controller, connect each unit to two sets of two ports on the
HBC controller, using two junction pipes (Y-joints). (See Fig. A.)
Connect an increaser (20A-to-32A) to the merged side of each junction pipe. (See Fig. A.)
When the junction pipes are connected to 16 HBC ports, the branched sides of the junction pipes cannot be connected to the
ports "4 and 5," "8 and 9," or "12 and 13" at the same time. (See Fig. B.)
When the junction pipes are connected to 8 HBC ports, the branched sides of the junction pipes cannot be connected to the
ports "4 and 5" at the same time. (See Fig. C.)
When a W/WP/WL100 or a 125 model indoor unit is connected to an HBC controller, the pipes that connect the unit to the
same set of HBC ports cannot be branched out to connect additional units.
3) Maximum capacity of indoor units connectable to an HBC controller for obtaining the rated performance
An HBC controller has two pumps. Each pump can accommodate the capacity equivalent to W/WP/WL175 indoor units.
When connecting the pipe to 16 HBC ports, make sure that the total capacity of the indoor units connected to ports "1 through
4 and 9 through 12" or "5 through 8 and 13 through 16" will not exceed W/WP/WL175 and will be equal as much as possible.
(See Fig. B.)
When connecting the pipe to 8 HBC ports, make sure that the total capacity of the indoor units connected to ports "1 through
4" or "5 through 8" will not exceed W/WP/WL175 and will be equal as much as possible. (See Fig. C.)
If the total capacity exceeds W/WP/WL175, the performance will be degraded.
HWE1708A
Pump 2 circuit Pump 1 circuit
1 2 3 4 5
Pump 2 circuit
1
Fig. C
Pump 2 circuit
6 7 8 9 10 11 12
Pump 1 circuit
2 3 4 5 6 7 8
- 59 -
Pump 1 circuit
13 14 15 16
GB