Vacon NX, Руководство пользователя

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6
vacon • 74 Electrical cabling and connections
Local contacts: http://drives.danfoss.com/danfoss-drives/local-contacts/
6. E
LECTRICAL CABLING AND CONNECTIONS
6.1 Power unit
How the power connections of VACON
®
NX Liquid-Cooled units are implemented depends on the
size of the unit. The smallest VACON
®
NX Liquid-Cooled unit (CH3) has terminal blocks for the
connections. In all other units, the connection is established using cables and cable clips or bolting
the busbars together.
The main circuit diagrams of each VACON
®
NX Liquid-Cooled drive chassis you will find in Appendix
2 on page 194.
6.1.1 Power connections
Use cables with heat resistance of at least +90
°
C. The cables and the fuses must be sized according
to the drive nominal OUTPUT current that you can find on the rating plate. Sizing according to the
output current is recommended because the drive input current never significantly exceeds the
output current. Installation of cables according to UL regulations is presented in Chapter 6.1.6.
In chassis CH5 and greater, the field cables (both motor and mains) must be connected to a specific
cable connection block (optional equipment). However, inside a switchgear, the cable connection
can be made directly to the drive.
VACON
®
Liquid-Cooled NX_8 inverter units must be equipped with a du/dt- or sine-filter.
Table 41 shows the minimum sizes of the Cu-cables and the corresponding aR fuse sizes.
If the motor temperature protection of the drive (see VACON
®
NX All in One Application Manual) is
used as an overload protection, the cable must be chosen accordingly. If three or more cables are
used in parallel each cable requires a separate overload protection.
These instructions apply only to cases with one motor and one cable connection from the AC drive
or inverter to the motor. In any other case, ask the factory for more information.
6.1.1.1 Mains cable
The mains cables of the size CH31 are connected to terminal blocks [see Figure 6] whereas busbar
connection is used for greater sizes, see drawings in Chapter 5.1.2.2. Mains cable type for EMC level
N in Table 35.
6.1.1.2 Motor cable
In order to avoid current sharing disbalance it is imperative to use symmetrical motor cables. We
also recommends to always use shielded cable whenever possible.
The motor cables of the size CH31 are connected to terminal blocks (see Figure 6) whereas busbar
connection is used for greater sizes, see drawings on on Chapter 5.1.2.2. Motor cable type for EMC
level N in Table 35. Ask factory for more information on the use of ferrite cores with the motor cable
in order to protect the motor bearings against motor bearing currents.
For information on control cables see Chapter 6.2.2.1 and Table 35.