4 Electrical Installation
4.1 Electrical Installation
4.1.1 Power Connections
Cabling and Fusing
NB!
Cables General
All cabling must comply with national and local regu-
lations on cable cross-sections and ambient tempera-
ture. UL applications require 75
°
C copper conduc-
tors. 75 and 90
°
C copper conductors are thermally
acceptable for the frequency converter to use in non
UL applications.
The power cable connections are situated as shown below. Dimension-
ing of cable cross section must be done in accordance with the current
ratings and local legislation. See the
Specifications section
for details.
For protection of the frequency converter, the recommended fuses
must be used or the unit must be with built-in fuses. Recommended
fuses can be seen in the tables of the fuse section. Always ensure that
proper fusing is made according to local regulation.
The mains connection is fitted to the mains switch if this is included.
3 Phase
power
input
130BA026.10
91 (L1)
92 (L2)
93 (L3)
95 PE
NB!
The motor cable must be screened/armoured. If an
unscreened/unarmoured cable is used, some EMC re-
quirements are not complied with. Use a screened/
armoured motor cable to comply with EMC emission
specifications. For more information, see
EMC specifi-
cations
in the
Design Guide
.
See section
General Specifications
for correct dimensioning of motor
cable cross-section and length.
Screening of cables:
Avoid installation with twisted screen ends (pigtails). They spoil the
screening effect at higher frequencies. If it is necessary to break the
screen to install a motor isolator or motor contactor, the screen must
be continued at the lowest possible HF impedance.
Connect the motor cable screen to both the de-coupling plate of the
frequency converter and to the metal housing of the motor.
Make the screen connections with the largest possible surface area (ca-
ble clamp). This is done by using the supplied installation devices with-
in the frequency converter.
Cable-length and cross-section:
The frequency converter 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 frequency converters are used together with Sine-wave filters to
reduce the acoustic noise from a motor, the switching frequency must
be set according to the instruction in par. 14-01
Switching Frequency
.
Term
. no.
96 97 98 99
U
V
W PE
1
)
Motor voltage 0-100% of mains volt-
age.
3 wires out of motor
U1 V1 W1
PE
1
)
Delta-connected
W
2
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.
1)
Protected Earth Connection
NB!
In motors without phase insulation paper or other in-
sulation reinforcement suitable for operation with
voltage supply (such as a frequency converter), fit a
Sine-wave filter on the output of the frequency con-
verter.
U
V
W
175ZA114.10
V
U
W
96
97
98
96
97
98
VLT HVAC Drive High Power Operating In-
structions
4 Electrical Installation
MG.11.F3.02 - VLT
®
is a registered Danfoss trademark
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4