Nx Networks NX series - Manual (Page 39)

Cabling and connections 39(86)
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 in Table 6-4.
Type Frame Tightening torque
[Nm]
Tightening torque
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.
6.1.4 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 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 >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
.