Power Connections - Danfoss VLT HVAC Drive FC 102 Design Manual

How to Install

5.2.7 Power Connections

NOTICE!
All cabling must comply with national and local
regulations on cable cross-sections and ambient
temperature. UL applications require 167°F [75°C] copper
conductors. Non-UL applications can use 167°F [75°C]
and 194°F [90°C] copper conductors.
5 5
The power cable connections are situated as shown in
Figure 5.51. Dimensioning of cable cross-section must
comply with the current ratings and local legislation. See
chapter 8.1 General Specifications for correct dimensioning
of motor cable cross-section and length.
For protection of the adjustable frequency drive, use the
recommended fuses unless the unit has built-in fuses.
Recommended fuses are listed in the Instruction Manual.
Ensure that proper fusing complies with local regulations.
The AC line input connection is fitted to the line power
switch if included.
Figure 5.51 Power Cable Connections
NOTICE!
The motor cable must be shielded/armored. If a non-
shielded/unarmored cable is used, some EMC
requirements are not complied with. Use a shielded/
armored motor cable to comply with EMC emission
specifications. For more information, see
chapter 5.7 EMC-compatible Installation.
Shielding of cables
Avoid installation with twisted shield ends (pigtails). They
spoil the shielding effect at higher frequencies. If it is
necessary to break the shield to install a motor isolator or
contactor, continue the shield at the lowest possible HF
impedance.
122
Design Guide
Connect the motor cable shield to both the decoupling
plate of the adjustable frequency drive and the metal
housing of the motor.
Make the shield connections with the largest possible
surface area (cable clamp) by using the installation devices
within the adjustable frequency drive.
Cable length and cross-section
The adjustable frequency drive has been EMC tested with
a given length of cable. Keep the motor cable as short as
possible to reduce the noise level and leakage currents.
Switching frequency
When adjustable frequency drives are used together with
sine-wave filters to reduce the acoustic noise from a
motor, the switching frequency must be set according to
the instructions in 14-01 Switching Frequency.
Term.
Table 5.41 Motor Cable Connection
1)
Protected Ground Connection
NOTICE!
In motors without phase insulation, paper or other
insulation reinforcement suitable for operation with
voltage supply, fit a sine-wave filter on the output of the
adjustable frequency drive.
Figure 5.52 Motor Cable Connection
Danfoss A/S © Rev. 2014-01-13 All rights reserved.
96 97 98 99
no.
U V W PE 1) Motor voltage 0–100% of AC line
voltage.
3 wires out of motor
U1 V1 W1 Delta-connected
PE 1)
W2 U2 V2 6 wires out of motor
U1 V1 W1 PE 1) Star-connected U2, V2, W2
U2, V2, and W2 to be interconnected
separately.
Motor
Motor
U V W
2 2 2
U V W
1 1 1
FC FC
96 97 98
U V W
2 2 2
V W
U
1 1
1
96 97 98
MG16C122