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7
6.1.4
Cable installation and the UL standards
To meet the UL (
) regulations, a UL-approved copper cable with a
minimum heat-resistance of +60/75
°
C must be used.
The tightening torques of the terminals are given in Table 6-6.
Frame Tightening
torque
[Nm]
Tightening torque
in-lbs.
MF2 0.5—0.6
4—5
MF3 0.5—0.6
4—5
MF4 0.5—0.6
4—5
MF5 1.2—1.5
10—13
MF6 4
35
Table 6-6. Tightening torques of terminals
6.1.5
Cable and motor insulation checks
1. Motor cable insulation checks
Disconnect the motor cable from terminals U, V and W of the frequency converter and from the
motor. Measure the insulation resistance of the motor cable between each phase conductor as
well as between each phase conductor and the protective ground conductor.
The insulation resistance must be >1M
Ω
.
2. Mains cable insulation checks
Disconnect the mains cable from terminals L1, L2 and L3 of the frequency converter and from
the mains. Measure the insulation resistance of the mains cable between each phase conductor
as well as between each phase conductor and the protective ground conductor.
The insulation resistance must be >1M
Ω
.
3. Motor insulation checks
Disconnect the motor cable from the motor and open the bridging connections in the motor
connection box. Measure the insulation resistance of each motor winding. The measurement
voltage must equal at least the motor nominal voltage but not exceed 1000 V. The insulation
resistance must be >1M
Ω
.
