Mitsubishi Electric JR Series Instruction Manual page 13

(2) Grounding (earthing)
The insulation material of the motor is an insulator and also is a conductor. Thus, the motor has a
capacitance between the ground. If the motor is not grounded, an induction voltage that is approx.
50 to 60% of the power voltage may be generated in proportion to this capacitance between the
frame and ground. To prevent accidents caused by electric shocks, always ground the motor
according to the Guide book of Electrical Facility Technology Standards Clause 18 to 28. A
grounding screw is provided in the motor's terminal box or on the lower part of the frame. If the
grounding screw loosens due to vibration during operation, sparks may be ignited at the grounding
section. Wire the grounding wire so that the grounding screw will not loosen because of the
grounding wire vibrating, and lock the grounding screw.
(3) Switch and fuse
Select the switch fuse according to the local power company's standards. Refer to Table 5 for the
capacity and wire size of the switch, fuse and instruments. Use of the Mitsubishi MS magnetic
switch for starting the motor and as overload protection is recommended.
(4) Structure of motor terminal lead sections and connection to power supply
a) Follow Table 7 when connecting the power supply to the lead wires or terminal block terminals.
Also refer to the connection nameplate in the terminal box and to the catalogs, etc.
b) Do not bend, pull or catch the power cable or motor lead wires with force.
c) Tighten the terminals firmly so that they will not be loosened by vibration during operation.
d) Do not disconnect or replace the wires in the motor.
Table 7 Structure of standard motor terminal lead sections and connection to power supply
Output (kW)
Frame
No.
2P, 4P 6P
Terminal block type
63 0.2
0.2
71 0.4
Terminal block type
80 0.75 0.4
to to to
112 3.7 2.2
132 - 3.7
Terminal block type
5.5
132 5.5
7.5
Lug type
7.5
160 11
to
to to 18.5
180 30
(SF-type
22kW)
Lug type
(SB-type
180 37
22kW)
to
to
30
225 90
to
75
Terminal symbol is indicated on
end of lead : for M6 screw
Terminal lead structure
U V W
Power connection terminal
M4 screw tightening torque 140 to 165N•cm
Wiring in
motor
U W
V
Power connection terminal
M4 screw tightening torque 140 to 165N•cm
Wiring in
motor
V2 W2
U1
V1 W1
Power connection terminal
M4 screw tightening torque 140 to 165N•cm
Wiring of lead wire
U1 W1
V1
V2 U2
W2
M6 terminal screw for standard
round crimp terminal
Lead-out wire arrangement
U1 V1 W1
U5 V5 W5
V2 W2 U2
V6 W6 U6
Connection method
Direct-online start
Power supply
R
U
U2
Direct-online start
V2 W2 U2
W1
U1 V1
Jumper
R S T
Power supply
Direct-online start
Power supply
R S T
U1 V1 W1
V2 W2 U2
Direct-online start
Case 400V Case 200V
Power supply Power supply
R S T R S
U1 V1 W1 U1 V1
U5 V5 W5 U5 V5
V2 W2 U2 V2 W2
V6 W6 U6 V6 W6
- 8 -
S T
W
V
- start
Starter
V2 W2 U2
V2 W2 U2
U1 V1 W1
Disconnect
U1 V1 W1
the jumper
Starter
- start
Starter
U1 V1 W1
U1 V1 W1
V2 W2 U2
V2 W2 U2
Starter
- start
Case 400V Case 200V
Starter Starter
U1 V1 W1 U1 V1 W1
T
U1 V1 W1 U1 V1 W1
W1
U5 V5 W5 U5 V5 W5
W5
V2 W2 U2 V2 W2 U2
U2
V6 W6 U6 V6 W6 U6
U6
V6 W6 U6 V6 W6 U6
Starter Starter
No. of outlet
wire terminals
3 terminals
V
U W
6 terminals
V1 W2
V2 W1
U1 U2
12 terminals
V1 W6
V2 W5
V5
W2
V6
W1
U1 U2 U5 U6