A
C
B
e
3
0
b
g
0
7
9
.1
0
A The PE conductor and the shield
C The shield
B The PE conductors
Illustration 16: Cables with PE Conductors
In all the enclosure sizes, to comply with the EMC standards, use the default values of the switching frequencies.
When using a safety switch, make sure that the EMC protection continues from the start of the cables until their ends.
The drive must obey the standard IEC 61000-3-12. To obey it, the short circuit power S
SC
must be a minimum of 120 R
SCE
at the
interface point between mains and the public mains. Make sure to connect the drive and the motor to mains with a short circuit power
S
SC
that is a minimum of 120 R
SCE
. If necessary, contact the mains operator.
6.2.1 Installation in a Corner-grounded Network
Corner-grounding can be used with the drive types (FR4 to FR9) with a rating of 3–300 A with a 208–240 V mains, and 261–730 A with a
380–500 V mains. In these conditions, change the EMC protection level to C4. See the instructions in
6.6 Installation in an IT System
Do not use corner-grounding with the drive types (FR4 to FR8) with a rating of 3–205 A with a 380–500 V mains or with a 525–690 V
mains.
Corner-grounding is permitted for the FR4–FR9 drives (main voltage 208–240 V) up to 3000 m and for the FR9–FR11 drives (main
voltage 380–500 V) up to 2000 m.
6.3 Grounding
Ground the AC drive in accordance with applicable standards and directives.
CAUTION
DAMAGE TO THE AC DRIVE FROM INSUFFICIENT GROUNDING
Not using a grounding conductor can damage the drive.
-
Make sure that the AC drive is always grounded with a grounding conductor that is connected to the grounding terminal
that is identified with the PE symbol.
Electrical Installation
Operating Guide | VACON® NXS/NXP Air-cooled
AQ275638903263en-000301 / DPD00910| 45
Danfoss A/S © 2020.02
