Nx Networks NX series user manual 3986, Cable installation and the UL standards

Cabling and connections 39(86)

6.1.3Cable 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 in Table 6-4.

Type	Frame	Tightening torque	Tightening torque
		[Nm]	in-lbs.
NX5 0003—0012	FR4	0.5—0.6	4—5
NX5 0016—0031	FR5	1.2—1.5	10—13
NX5 0038—0061	FR6	4	35
NX5 0072—0105	FR7	10	85
NX5 0140	FR8	20/9*	170/76*
NX5 0168—0205	FR8	40/22*	340/187*

Table 6-4. Tightening torques of terminals

* Tightening torque of terminal connection to the isolative base in Nm/in-lbs.

6.1.4Cable 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 >1MΩ .

2.Mains cable insulation checks

Disconnect the motor cable from terminals L1, L2 and L3 of the frequency converter and from the mains. 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 >1MΩ .

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 >1MΩ .

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