Technical Manual
FT420
– Iss 2.4
26
Table 14 Relay Expansion Board Connections
7
Designator
Type
Pin
Usage
Label
Description
TB1
Removable
screw
terminal
block
1
DC power input
+24V
24V
DC
@ 300mA.
Connected to the main control board
backup power output.
2
GND
3
Earth connection
EARTH
Solid Earth connection shall be
provided.
TB2
Removable
screw
terminal
block
1
Relay 1 output connection
ACT
Dry-contact relay output.
Jumper configurable N/C or N/O.
“ACT” either N/C or N/O depending on
jumper setting.
“COM” common
Maximum carry current 2A @ 30V.
2
COM
3
Relay 2 output connection
ACT
4
COM
5
Relay 3 output connection
ACT
6
COM
7
Relay 4 output connection
ACT
8
COM
TB3
Removable
screw
terminal
block
1
Relay 5 output connection
ACT
2
COM
3
Relay 6 output connection
ACT
4
COM
5
Relay 7 output connection
ACT
6
COM
7
Relay 8 output connection
ACT
8
COM
CON1
IDC20 Cable
connector
Incoming control expansion
bus connector.
N/A
CON2
IDC20 Cable
connector
Outgoing control expansion
bus connector
N/A
7
Table Abbreviation: “Pin” = Pin No., “+” = Positive, “-” = Negative, “N/A” = Not Applicable, “N/O” = Normally Open, “N/C” =
Normally Closed, “C” = Common.