Vacon NXI Series - Cable Installation and the UL Standards

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6
6.1.3 Cable installation and the UL standards
To meet the UL (Underwriters Laboratories) 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 below in Table 6-7.
Type
Frame
Tightening torque
[Nm]
NXI_0003 - 0012 5
FR4
0.5—0.6
NXI_0038 - 0061 5
NXI_0004 - 0034 6
FR6
10
NXI_0072 - 0105 5
NXI_0041 - 0080 6
FR7
10
NXI_0140 5
NXI_0062 – 0100 6
FR8
20/9*
Table  6-7. Tightening torques of terminals
* Tightening torque of terminal connection to the isolative base in Nm.
6.1.4 Cable and motor insulation checks
1. Motor cable insulation checks
Disconnect the motor cable from terminals U, V, and W of the inverter 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.
2. DC supply cable insulation checks
Disconnect the DC supply cable from terminals B- and B+ of the inverter and from DC supply.
Measure the insulation resistance between each conductor and ground.
The insulation resistance must be >1M.
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 1,000 V.
The insulation resistance must be >1M.