6
d.
Based upon the mode of operation (“Flow” or “No-
Flow”) required, complete the appropriate steps to
connect wires to flow switch. Use a phillip’s head
screwdriver to loosen and tighten switch terminal
screws when attaching wires.
For “Flow” Mode of Operation (Fig. 1)
If the flow switch will be used to actuate a signal,
alarm or other device when
flow
occurs, connect
the wire from that device to the “N.O.” contact.
Connect the “Hot” power supply wire to “C” terminal.
For “No Flow” Mode of Operation (Fig. 2)
If the flow switch will be used to actuate a signal,
alarm or other device when
no flow
occurs, connect
the wire from that device to the “N.C.” contact.
Connect the “Hot” power supply wire to “C” terminal.
FLOW
OPENS
CIRCUIT
FLOW
CLOSES
CIRCUIT
COMMON
1
2
3
Flow
Opens
Circuit
Normally
closed
3
Common
1
Flow
Closes
Circuit
2
(
(
Normally
open
(
(
Common
(
(
FS4-3
LINE
LOAD
Fig. 1
HOT
3
1
2
FS4-3
LINE
LOAD
Fig. 2
HOT
3
1
2
c.
Determine which switch action is required for the
flow switch.
• “Flow” means that the switch will close circuit
C.-N.O. and open circuit C.-N.C. when flow rate
is increased above setpoint of flow switch.
• “No Flow” means that the switch will open circuit
C.-N.O. and close circuit C.-N.C. when flow rate
is decreased below setpoint of flow switch.
