Mitsubishi Electric MELSERVO-J4 Series Transition Handbook page 273

Part 5: Review on Replacement of MR-J3-DU_ with MR-J4-DU_
(3) Connection instructions
Keep the wires between the converter unit and the brake unit, and between the resistor unit and the
brake unit as short as possible. For wires longer than 5 m, twist the wires five times or more per meter.
The wires should not exceed 10 m even when the wires are twisted. If wires exceeding 5 m without
twisted or exceeding 10 m with or without twisted are used, the brake unit may malfunction.
Converter unit
L+
L-
5 m or less
(4) Wires
(a) Wires for the brake unit
For the brake unit, HIV wire (600 V Grade heat-resistant polyvinyl chloride insulated wire) is
recommended.
1) Main circuit terminal
N/- P/+ PR
Terminal block
2) Control circuit terminal
PC SD
BUE
A B C
Jumper
Terminal block
Brake unit Resistor unit
P/+ P P
N/- PR PR
5 m or less
Brake unit
200 V class FR-BU2-55K
FR-BU2-H55K
400 V class
FR-BU2-H75K
POINT
Under tightening can cause a cable disconnection or malfunction. Over
tightening can cause a short circuit or malfunction due to damage to the screw
or the brake unit.
SD SD
SD
RES
MSG MSG
Converter unit
Twist
L+
L-
10 m or less
Crimp terminal
Main circuit
terminal
N/-, P/+,
screw size
PR,
M6
M5
M6
Wire the stripped cable after twisting to prevent the cable
from becoming loose. In addition, do not solder it.
Screw size: M3
Tightening torque: 0.5 N•m to 0.6 N•m
2
Wire size: 0.3 mm to 0.75 mm
Screw driver: Small flat-blade screwdriver
(Tip thickness: 0.4 mm/Tip width 2.5 mm)
5 - 72
Brake unit Resistor unit
Twist
P/+ P P
N/- PR PR
10 m or less
Tightening
N/-, P/+, PR,
torque
HIV wire
[N•m]
[mm
14-6 4.4 14
5.5-5 2.5 5.5
14-6 4.4 14
Insulator
Core
6 mm
2
Wire size
AWG
2 ]
6
10
6