3-5
3.2.4 Control
board
The following are the details of the control board.
Warning
Do not remove the protective cover on the control board or the cover of
the I/O terminal block when the power is turned on.
Otherwise, it may lead to an electric shock.
Table 3-2-4 (a) Connector assignments
No. Connected
to No. Connected
to No.
Connected to
CN1
Device in panel
CN7
Device in panel
CN13
Flow switch No.2
CN2
(Not in use)
CN8
Device in panel
CN14
(Not in use)
CN3
Device in panel
CN9
(Not in use)
CN15
Control panel
high-temperature sensor *
1
CN4
Device in panel
CN10
Pressure transmitter
CN16
High-temperature sensor
No.1
CN5
(Not in use)
CN11
(Not in use)
CN17
High-temperature sensor
No.2
CN6
Device in panel
CN12
Flow switch No.1
CN18 Low-temperature sensor *
2
*1 For models fitted with outdoor cover, this sensor is connected depending on the specifications.
*2 The low-temperature sensor is connected only to freeze-proof models (special specifications).
Table 3-2-4 (b) Designations and applications of I/O terminal block
Designation Application Designation
Application
IL1, IL2
Interlocking signal
B1 to B5
Alarm signal output
1E0 to 1E4
Receiver tank No.1 level detection
electrode
BC
Alarm signal output common
2E0 to 2E4
Receiver tank No.2 level detection
electrode
VR, VT
Alarm power (power voltage)
1N1, 1N2
Receiver tank No.1 solenoid valve
control electrode
RH, TH*
3
Freeze-proof heater (power voltage)
2N1, 2N2
Receiver tank No.2 solenoid valve
control electrode
SVC, SV1
Receiver tank No.1 solenoid valve
(power voltage)
M1, M2
No.1, No.2 operation signal
SVC, SV2
Receiver tank No.2 solenoid valve
(power voltage)
MC
Operation signal common
*3 The freeze-proof heaters are connected only to freeze-proof models (special specifications).
I/O terminal block
Operation
power
switch
Control board
Fig. 3-2-4 Detailed drawing of control board
