18
4.3 How to Wire the Control Unit
You will wire this unit according to the following examples.
For the wiring of other units such as an extension
unit or option unit, refer to the user’s manual of each product.
Precautions for Wiring
Caution
・
In order to prevent the invasion of noise, the transmission signal lines and output signal lines must not
be placed close to or bound together with the power lines or high voltage lines. When lying parallel to the
power lines or high voltage lines, refer to the following table for the separation distance. (except the input
part of the terminal block)
Conditions
Distance
Power lines of 600 V or less
300 mm or more
Other power lines
600 mm or more
*When there is concern about the invasion of noise, it is recommended to use shielded cables for the
wiring with the above separation distance.
・
For actual use, ground the frame grounding (FG) terminal. (Type D grounding: Type 3 grounding)
・
When the unit is subjected to an insulation resistance test or a pressure test, do not connect the FG
terminal.
For the applied place, refer to
■
How to connect wires
<Terminals for auxiliary power supply and MODBUS RTU communication>
For the use of an applicable crimp-type terminal and electric wire, refer to the following table.
Tighten the terminal screws with a specified torque as the following table.
Applicable wire
Tightening torque
Applicable crimp-type terminal
Auxiliary power terminal
Stranded wire: AWG 22 to 16
(0.3 to 1.250 mm
2
)
Solid wire:
AWG 22 to 16
(
φ
0.65 to 1.2 mm)
0.8 to 1.0 N
・
m
For M3.5 screw with outer
diameter of 7.1 mm or less
MODBUS RTU
communication terminal
SPEV (SB)
– MPC – 0.2 × 1P or
equivalent
0.5 to 0.6 N
・
m
For M3 screw with outer
diameter of 6.1 mm or less
<Terminals for external output (contact output/analog output)>
The wire stripping length must be 10 to 11 mm.
When using a stranded wire, use with a rod terminal or twist the wire tip so as not to scatter the filaments.
To connect/disconnect the wire to/from the terminal, conduct that by pressing the push button. After inserting the wire,
check that it is properly done.
Insert the wire as far as it goes into the terminal block.
The following table shows applicable electric wires for use.
Applicable wire
Applicable crimp-type terminal
Stranded wire: AWG 20 to 16 (0.5 to 1.25 mm
2
)
Solid wire: AWG 24 to 17 (
φ
0.5 to 1.2 mm)
TGV TC-1.25-11T produced by NICHIFU
or its equivalent
■
Precautions for compliance with UL
To comply with the UL standards, observe the following conditions for wiring.
・
Do not connect three or more wires to one terminal block.
・
Perform crimping of the wires to be connected to the terminal block.
■
An example of system configuration for MODBUS RTU communication
The following illustrates an example of system configuration when this unit is to the superior monitoring systems via
MODBUS RTU communication.
Connection of the MODBUS RTU communication terminals (485+, 485-, SLD, and Ter)
1. Use shielded twisted pair cables for transmission lines.
For the recommended cables, refer to
13.2 Specifications of MODBUS Communication
2. Install 120 ohm termination resistors to the devices at both ends of the MODBUS transmission line.
For this unit, short-circuiting the 485- and Ter terminals enables 120 ohm termination.
3. Ground with thicker wires to decrease impedance.
4. The MODBUS transmission lines must not be placed close to or bound together with the high voltage lines.
5. Ground the SLD terminal at one end.
or
USB
or
LAN
MODBUS RTU (RS-485)
120 ohm termination
PC
PLC
120 ohm termination
Max connectable number: 31 units
