26
VLT
®
Series 3500
Input Power Wiring
VLT Type 3502-3504, 208/
230 volt; VLT Type 3502-
3511, 380 volt; and VLT
Type 3502-3508,460 volt
with NEMA 1 or NEMA 12
enclosures have a plastic
bottom cover with marked
provision for conduit entry.
To meet UL requirements, a
bonding plate must be in
place in the plastic bottom
cover. The plate must be
grounded to the chassis,
and the conduit grounded to
the plate.
If the grounding plate is not
factory installed, it must be
installed in the drives that
have a plastic bottom panel
to ensure proper grounding
of the conduit. Connect the ground wire from the bonding
plate to the ground tab marked GND. This tab is located
near the AC line terminal strip. Mount the bottom cover on
the control unit.
The conduit entries provide strain relief for the wires in
drives mounted in NEMA 1 or NEMA 12 enclosures. With
the chassis mount drives, the power and control wires
need to be have strain relief supplied by the installer. Do
not rely upon the terminal blocks to provide strain relief.
VLT Type 3516-3562, 460 volt, and VLT Type 3508-3532,
208/230 volt have a metal bottom with cutouts for conduit
entry.
VLT Type 3575-3800, 460 volt and VLT Type 3542-3562,
208/230 volt drives have a wiring access plate on both
the bottom and the side of the drive. It is recommended
that the larger, bottom wiring access plate be used for
conduit entry. Remove the plate before drilling for the
power and control wires. Drill all required holes before
running any of the wires through the plate. Do not make
any of the holes any larger than required to fasten to
conduit. Reinstall the plate after drilling and wiring the
drive. The plate must be in place to provide protection to
the drive and provide proper air flow for cooling.
Wiring access plate on bottom of enclosure
WARNING
!
The enclosure for these larger drives and for the auxiliary
enclosures is made of steel. To avoid getting steel chips
in the electronics, do not drill any holes until after the unit
has been installed in a vertical position. Remove the
conduit plate before drilling.
Shielded Wires
Wires to control signals should be shielded to reduce
radio noise interference.
When radio noise (RFI or EMI) is a concern, shielded
cable should be used between the drive and the motor.
If unshielded control wires are used, control inputs are
subject to signal disturbances. Such disturbances may
affect drive operation. Extreme noise levels may disturb
the microprocessor of the control card. The drive may
fault and “EXCEPT” will appear in the display.
The shield of the control wires must be grounded at the
cable clamp at the bottom of the drive, but the shield
must continue with the cable all the way up to the control
card. The shield is not to be connected to any of the
terminals at the control card .
For safety reasons, the insulation around the shield
should only be removed where it is connected to the
cable clamp. The insulation should be left on the shield
between the clamp and the terminals.
Generally speaking, all conductors coming from a
shielded control cable must be as short as possible. Long
conductor ends attract noise. The shield must be
connected to the chassis by means of the cable clamp.
Long pigtails on the shield reduce the effectiveness of the
shield.
Danfoss VLT
®
and CE Marking
Danfoss CE marks our VLT
®
Adjustable Frequency
Drives (AFD) according to the Electro Magnetic
Compatibility (EMC) Directive 89/336/EEC and Low-
Voltage Directive 73/23/EEC.
When the installation specification is followed and
shielded motor cables are used per instruction manuals
provided with the drive, we guarantee the AFD complies
with the EMC Directive 89/336/EEC. Please consult the
RFI Filter Product Manual and EMC Installation
Guidelines (175R5187).
Upon request we will issue a declaration of conformity to
the EMC and low-voltage directives. A manufacturer's
declaration for the Machinery Directive 89/392/EEC is
also available.
