Danfoss VLT AutomationDrive FC 301 Series Design Manual page 144

Electrical Installation
9.4 Motor Connection
WARNING
INDUCED VOLTAGE
Induced voltage from output motor cables that run
together can charge equipment capacitors even with the
equipment turned off and locked out. Failure to run
output motor cables separately or use shielded cables or
metal conduits could result in death or serious injury.
•
run output motor cables separately, or
•
use shielded cables or metal conduits
Motor Connection
NOTICE!
To comply with EMC emission specifications, shielded/
armored cables are required. For more information, see
chapter 5.2.1 EMC Test Results and Figure 3.3.
See chapter 6.2 General Specifications for correct
dimensioning of motor cable cross-section and length.
9 9
Term. 96 97
no.
U
U1 V1 W1
W2 U2 V2
U1 V1 W1
Table 9.17 Terminal Descriptions
1)
Protected Ground Connection
Motor
U V
2 2
U V
1 1
FC
96 97
Figure 9.29 Star and Delta Connections
142
98 99
V W 1) Motor voltage 0–100% of AC line
PE
voltage.
3 wires out of motor
Delta-connected
1)
PE
6 wires out of motor
1) Star-connected U2, V2, W2
PE
U2, V2 and W2 to be intercon-
nected separately.
Motor
W
U V
2 2
V
U
W
1
1 1
FC
98
96 97
Design Guide
NOTICE!
In motors without phase insulation paper or other
insulation reinforcement suitable for operation with
voltage supply (such as an adjustable frequency drive),
fit a sine-wave filter on the output of the adjustable
frequency drive.
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
motor contactor, the shield must be continued at the
lowest possible HF impedance.
NOTICE!
Strip a piece of the motor cable to expose the shield
behind the cable clamp AND connect the ground
connection to terminal 99.
Connect the motor cable shield to both the decoupling
plate on the adjustable frequency drive and to the metal
housing on the motor.
Make the shield connections with the largest possible
surface area (cable clamp). This is done by using the
supplied installation devices in the adjustable frequency
drive.
If it is necessary to split the shield to install a motor
isolator or motor relay, the shield must be continued with
the lowest possible HF impedance.
Cable length and cross-section
The adjustable frequency drive has been tested with a
given length of cable and a given cross-section of that
cable. If the cross-section is increased, the cable
capacitance - and thus the leakage current - may increase,
thereby requiring that the cable length is reduced
accordingly. Keep the motor cable as short as possible to
reduce the noise level and leakage currents.
W Switching frequency
2 2
When adjustable frequency drives are used with sine-wave
filters to reduce the acoustic noise from a motor, the
W
1
switching frequency must be set according to the sine-
wave filter instruction in 14-01 Switching Frequency.
1.
98
2.
3.
Rev. 2014-04-04 All rights reserved.
Fasten a decoupling plate to the bottom of the
adjustable frequency drive with screws and
washers from the accessory bag.
Attach motor cable to terminals 96 (U), 97 (V), 98
(W).
Connect to ground connection (terminal 99) on
decoupling plate with screws from the accessory
bag.
MG33BF22