Wiring; Wiring Procedure - Mitsubishi FX3U Series User Manual

FX Series Programmable Controllers
3U
User's Manual - MODBUS Serial Communication Edition
4.

Wiring

This chapter explains the wiring.
WIRING PRECAUTIONS
• Cut off all phases of the power supply externally before installation or wiring work in order to avoid damage to the
product or electric shock.
• Make sure to attach the terminal cover, offered as an accessory, before turning on the power or initiating
operation after installation or wiring work.
Failure to do so may cause electric shock.
WIRING PRECAUTIONS
• Make sure to observe the following precautions in order to prevent any damage to the machinery or accidents
due to abnormal data written to the PLC under the influence of noise:
1) Do not bundle the main circuit line together with or lay it close to the main circuit, high-voltage line, or load
line.
Otherwise, noise disturbance and/or surge induction are likely to take place.
As a guideline, lay the control line at least 100mm (3.94") or more away from the main circuit, high-voltage
line, or load line.
2) Ground the shield wire or shield of the shielded cable at one point on the PLC. However, do not ground them
at the same point as the high-voltage lines.
• Make sure to properly wire the FX Series terminal blocks in accordance with the precautions below in order to
prevent electric shock, a short-circuit, wire breakage, or damage to the product:
- Tightening torque should be between 0.5 and 0.8 N m.
• Observe the following items when wiring to the European terminal board.
Failure to do so may cause electric shock, a short-circuit, disconnection, or damage to the product.
- The disposal size of the cable end should follow the dimensions described in this manual.
- Tightening torque should be between 0.22 and 0.25 N m.
- Twist the end of strand wire and make sure that there are no loose wires.
- Do not solder-plate the electric wire ends.
- Do not connect more than the specified number of wires or electric wires of unspecified size.
- Affix the electric wires so that neither the terminal block nor the connected parts are directly stressed.
4.1

Wiring Procedure

1) Selecting the connection method
Select the wiring method suitable to the application.
2) Preparing for wiring
Prepare cables and terminal resistors required for wiring.
3) Turning OFF the power to the PLC
Before wiring, make sure that the PLC power is OFF.
4) Wiring communication equipment
Connect communication equipment operating in accordance with MODBUS RS-485 or MODBUS RS-
232C.
20
→ For communication in accordance with MODBUS RS-232C, refer to Section 4.4.
→ For communication in accordance with MODBUS RS-485, refer to Section 4.5.
4.1 Wiring Procedure
→ For details, refer to Section 4.2.
→ For details, refer to Section 4.3.
4 Wiring