Rockwell Automation 1790P-4R0 CompactBlock LDX I/O RTD/Resistance Input Module - Manual (Page 26)

Publication 1790-UM002A-EN-P
2-14 Installation and Wiring
To wire your module follow these steps.
1. At each end of the cable, strip some casing to expose the individual
wires.
2. Trim the signal wires to 2-inch (5 cm) lengths. Strip about 3/16 inch (5
mm) of insulation away to expose the end of the wire.
3. At the module end of the cable, twist the drain wire and foil shield
together, bend them away from the cable, and apply shrink wrap.
Then earth ground via a panel or DIN rail mounting screw at the end
of the module. Keep the length of the drain wire as short at possible.
4. At the other end of the cable, cut the drain wire and foil shield back to
the cable and apply shrink wrap.
5. Connect the signal wires to the terminal block as described for each
type of input. See Wiring RTDs below or Wiring Resistance Devices
(Potentiometers) on page 2-15.
6. Connect the other end of the cable to the analog input device.
7. Repeat steps 1 through 6 for each channel on the module.
Wiring RTDs
Three types of RTDs can be connected to the module:
•
2-wire RTD, which is composed of an RTD EXC (excitation) lead wire
and a RTN (return) lead wire.
•
3-wire RTD, which is composed of a Sense and 2 RTD lead wires
(RTD EXC and RTN).
•
4-wire RTD, which is composed of a Sense and 2 RTD lead wires
(RTD EXC and RTN). The second sense wire from the 4-wire RTD is
left open.
ATTENTION
ÿ
Be careful when stripping wires. Wire fragments that fall
into a module could cause damage at power up.