Wiring Precautions - Mitsubishi Electric FR-F820-04750 Instruction Manual

Installation and wiring
2.6.4

Wiring precautions

● It is recommended to use a cable of 0.3 to 0.75 mm² for the connection to the control circuit
terminals.
● The wiring length should be 30 m (200 m for the terminal FM) at the maximum.
● Use two or more parallel micro-signal contacts or twin contacts to prevent contact faults when
using contact inputs since the control circuit input signals are micro-currents.
Micro signal contacts
● To suppress EMI, use shielded or twisted cables for the control circuit terminals and run them away
from the main and power circuits (including the 200 V relay sequence circuit). For the cables
connected to the control circuit terminals, connect their shields to the common terminal of the
connected control circuit terminal. When connecting an external power supply to the terminal
PC, however, connect the shield of the power supply cable to the negative side of the external
power supply. Do not directly earth (ground) the shield to the enclosure, etc.
● Always apply a voltage to the fault output terminals (A1, B1, C1, A2, B2, C2) via a relay coil, lamp, etc.
● For the FR-F820-03160(75K) or higher and FR-F840-02160(90K) or higher, separate the wiring of
the control circuit away from the wiring of the main circuit.
Make cuts in rubber bush of the inverter side and lead the wires through.
Rubber bush
(viewed from inside)
Fig. 2-36:
FR-F800
Twin contacts
Make cuts along the lines on the inside with
a cutter knife.
Wiring of the control circuit of the FR-F820-03160(75K) or higher and FR-F840-02160(90K)
or higher
Fig. 2-35:
Contacts
Control circuit
I001021E
Wiring example
I002375E
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