Uni-I/O™
Unitronics
5
All wiring activities should be performed while power is OFF.
Unused points should not be connected (unless otherwise specified). Ignoring this
directive may damage the device.
Double-check all wiring before turning on the power supply.
Caution
To avoid damaging the wire, use a maximum torque of 0.5 N·m (5 kgf·cm).
Do not use tin, solder, or any substance on stripped wire that might cause the
wire strand to break.
Install at maximum distance from high-voltage cables and power equipment.
Wiring Procedure
Use crimp terminals for wiring; use 26-12 AWG wire (0.13 mm
2
–3.31 mm
2
).
1. Strip the wire to a length of 7±0.5mm (0.250–0.300 inches).
2. Unscrew the terminal to its widest position before inserting a wire.
3. Insert the wire completely into the terminal to ensure a proper connection.
4. Tighten enough to keep the wire from pulling free.
Uni-I/O™ Connection Points
All wiring diagrams and instructions in this
document refer to the Uni-I/O™ connection
points.
These points are arranged in two groups of 2
points as shown in the figure to the right.
Top group
Input connection points (0-1)
Bottom group
Input connection points (2-3)
Wiring Guidelines
In order to ensure that the device will operate properly and to avoid electromagnetic
interference:
Use a metal cabinet. Make sure the cabinet and its doors are properly earthed.
Use wires that are properly sized for the load.
Use shielded cables for wiring RTD signals;
do not use the cable shield as a signal common (CM) / return path.
Individually connect each functional ground point ( ) to the earth of the system
(preferably to the metal cabinet chassis).
Use the shortest and thickest wires possible: less than 1m (3.3’) in length, minimum
thickness 14 AWG (2 mm
2
).
Earthing the cables' shield:
Connect the cable shield to the earth of the system - preferably to the metal cabinet
chassis. Note that the shield must be connected only at one end of the cable;
typically, earthing the shield at the Uni-I/O™ end performs better.
Keep shield connections as short as possible.
Ensure shield continuity when extending shielded cables.