Mitsubishi Electric MELSERVO-J2S Series Transition Handbook page 215

Part 5: Review on Replacement of MR-J2S-30 kW or Higher Capacity Models with MR-J4-DU_
(3) Wiring precautions
Use as short wires as possible between a converter unit and brake unit and between a resistor unit and
a brake unit. If using a wire of 5 m or longer, be sure to use a twist wire (with 5 or more twists in 1 m).
Make sure that a wire is 10 m or shorter even when it is a twisted wire. If a wire of 5 m or longer is not a
twisted wire, or if a wire is a twisted wire and longer than 10 m, a malfunction may occur to a brake unit.
Converter unit
L+
L-
5 m or less
(4) Wires
(a) Wires for brake units
HIV wire (600 V grade heat-resistant polyvinyl chloride insulated wire) is recommended for use in
brake units.
1) Main circuit terminals
N/- P/+
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
PR
200 V
FR-BU2-55K
class
400 V FR-BU2-H55K
class
FR-BU2-H75K
POINT
Fix a screw tightly otherwise the wire may come off or a malfunction may occur.
Fixing a screw too tightly can damage the screw or brake unit, resulting in a
short circuit or malfunction.
SD SD SD
RES MSG MSG
Converter unit
Twist
L+
L-
10 m or less
Crimp
Main
terminal
circuit
terminal
N/-, P/+,
screw
PR,
size
M6 14-6
M5 5.5-5
M6 14-6
Do wiring with the stripped cable twisted to prevent it from
becoming loose. Do not solder it.
Screw size: M3
Tightening torque: 0.5 N•m to 0.6 N•m
2
Cable gauge: 0.3 mm
Driver: Small-size slotted screw driver
(Blade thickness: 0.4 mm/Blade width: 2.5 mm)
5 - 54
Brake unit Resistor unit
Twist
P/+ P P
N/- PR PR
10 m or less
Cable gauge
Tightening
torque N/-, P/+, PR,
[N•m]
HIV wire
[mm 2 ]
4.4 14
2.5 5.5
4.4 14
Insulator
Core
6 mm
2
to 0.75 mm
AWG
6
10
6