SM43-J-R20 Installation Guide
6
Unitronics
Power Supply
The controller requires an external 24VDC power supply.
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.
Earthing the OPLC
To maximize system performance, avoid electromagnetic interference by:
Mounting the controller on a metal panel.
Connect each common and ground connection directly to the earth ground of your system.
For ground wiring use the shortest and thickest possible wire.
Communication Port
This series comprises a USB port and a CANbus port
Turn off power before making communications connections.
Caution
Always use the appropriate port adapters.
The USB port is not isolated. Make sure that the PC and the controller are grounded to
same potential.
The USB port may be used for programming, OS download, and PC access.
