Before making wiring connections from each unit to the system controller, make sure that
the electrical power of each unit including the system controller has been disconnected.
1. Remove the front cover from the system controller and the cover of the external re-
mote controller cord terminal block of each water heater.
Connecting the communication cord to Unit 1
2. Using the remote controller cord supplied with the water heater, insert the end with
Y terminals through one (need to be cut to make a hole) of the grommets in the
base of the system controller. Connect the Y terminals to terminal block “01”.
3. Cut off the connector on the other end of the remote controller cord. Attach the Y
terminals in place of the connector.
4. Connect the free end of the remote controller cord to the external remote controller
cord terminal block of Unit 1.
Connecting the communication cord to Units 2-24
5. Connect Units 2-24 in the same way as Unit 1. Be sure to connect the units to the
water heater terminals in the system controller, following the list of connections of
water heaters.
* For the terminal block that is not used, nothing should be done.
* After all connections are made, replace the front cover of the system controller
(taking special care to do not crush any wires) and the covers of the external remote
controller cord terminal blocks of all connected water heaters.
01
02
03
04
05
06
Water Heater Terminals (Inside System Controller)
Terminal block* for remote controller cord.
* The terminal block is depending on each water heater.
Refer to the water heater's installation manual for detail information.
Remote controller cords
Unit 1
Unit 2
Unit 3
Group 1
Main
Controller
Power
PCB
Sub Controller
1
Sub Controller
2
Group 2
Group 3
Group 4
System Controller
Connect the communication cords with the water heaters.
Connection with Water Heater
List of connections of water heaters
Group No.
Group 1
Group 2
Group 3 (Only -24M)
Group 4 (Only -24M)
Number of
connected units
Sub power of
each sub
controller
○
○
○
○
Water Heater
Terminal No. 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Group 1 Group 2 Group 3 Group 4
Number of W
ater Heaters
7 units
4 units 3 units 0 units 0 unit
8 units
4 units 4 units 0 units 0 unit
9 units
5 units 4 units 0 units 0 unit
10 units
5 units 5 units 0 units 0 unit
11 units
6 units 5 units 0 units 0 unit
12 units
6 units 6 units 0 units 0 unit
13 units
6 units 5 units 2 units 0 unit
14 units
6 units 6 units 2 units 0 unit
15 units
6 units 6 units 3 units 0 unit
16 units
6 units 6 units 4 units 0 unit
17 units
6 units 6 units 5 units 0 unit
18 units
6 units 6 units 6 units 0 unit
19 units
6 units 6 units 5 units 2 units
20 units
6 units 6 units 6 units 2 units
21 units
6 units 6 units 6 units 3 units
22 units
6 units 6 units 6 units 4 units
23 units
6 units 6 units 6 units 5 units
24 units
6 units 6 units 6 units 6 units
*Connect water heaters at the gray points.
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