Rev A1
FT900003
9 of 14
WIRING
Step Six
Wiring the Relay Output:
The Thermo‐Flo™ relay output can be wired as a dry contact to a VDC or VAC power
source. The Thermo‐Flo™ does require 14‐36 VDC power to operate the sensor and switch the relay. All
installations below identify a dry switch state as the normal position of the relay.
Switching a Normally Open DC Load (Open during Flow, Closed during No‐Flow):
The Red wire connects to Positive (+) of the power
supply and the Black wire connects to Negative (‐). The
LOAD can be attached to either the Green or White
wires. Complete the circuit by connecting the Green to
(+) VDC power or White to (‐) VDC power (see
illustration to the right).
Switching a Normally Closed DC Load (Closed during Flow, Open during No‐Flow):
The Black wire connects to positive (+) of the power
supply and the Red wire connects to Negative (‐). The
Load can be attached to either the Green or White
wires. Complete the circuit by connecting the Green
to (+) VDC power or White to (‐) VDC power (see
illustration to the right).
Switching a Normally Open AC Load (Open during Flow, Closed during No‐Flow):
The Red wire connects to Positive (+) of the DC power
supply and the Black wire connects to Negative (‐). The
LOAD can be attached to the Green wire and the Hot of
the VAC power. Connect the white to the Neutral of
the VAC power (see illustration to the right). Low
voltage VAC is less than 36 VAC.
Switching a Normally Closed AC Load (Closed during Flow, Open during No‐Flow):
The Black wire connects to Positive (+) of the DC
power supply and the Red wire connects to Negative
(‐). The LOAD can be attached to the Green wire and
the Hot of the VAC power. Connect the White to the
Neutral of the VAC power (see illustration to the
right). Low voltage VAC is less than 36 VAC.
For all Sensor Wiring diagrams above:
Sensor Power: Red and Black Wires (36 VDC Max.)
Relay Rating: Green and White Wires (60VA, 1A Max.)
