Samba™ OPLC™ Installation Guide
10
Unitronics
Relay Outputs
Transistor Outputs
SM43-J-R20/SM35-J-R20
SM43-J-T20/SM35-J-T20
Increasing Contact Life Span
SM43-J-R20/SM35-J-R20- Only
To increase the life span of the
relay output contacts and protect
the device from potential damage
by reverse EMF, connect:
A clamping diode in parallel with
each inductive DC load
An RC snubber circuit in parallel with
each inductive AC load
Power Supply
The controller requires an external 24VDC power supply.
Note: Photo is for illustration purposes only.
1. The power supply must include double insulation. Outputs must be rated as
SELV/PELV/Class 2/Limited Power.
2. Use separate wires to connect the functional
earth line (pin 3) and the 0V line (pin 2) to the
system earth ground.
3. Install an external circuit breaker. Guard
against short-circuiting in external wiring.
4. Double-check all wiring before turning
on the power supply.
5. Do not connect either the ‘Neutral’ or ‘Line’
signal of the 110/220VAC to device’s 0V pin.
6. In the event of voltage fluctuations or non-
conformity to voltage power supply
specifications, connect the device to
a regulated power supply.
