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ELECTRICAL CABLING AND CONNECTIONS
Tel. +358 (0)201 2121 • Fax +358 (0)201 212 205
6
6.1.8
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.
6.1.9
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 be-
tween each phase conductor and the protective ground conductor.
The insulation resistance must be at least 1…2M
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 at least 1…2M
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 1000V. The insulation resistance must be at least
1…2M
Ω
.