Sensitive Equipment - Parker 650G Product Manual

10-5
Certification for the Drive
0A = 0 Volts Analogue
0D = 0 Volts Digital
PE = Protective Earth
f = External Filter
VSD = Variable Speed Drive
PLC = Programmable Logic Controller

Sensitive Equipment

The proximity of the source and victim circuit has a large effect on radiated coupling. The
electromagnetic fields produced by VSDs fall off rapidly with distance from the cabling/cubicle.
Remember that the radiated fields from EMC compliant drive systems are measured at least 10m
from the equipment, over the band 30-1000MHz. Any equipment placed closer than this will see
larger magnitude fields, especially when very close to the drive.
Do not place magnetic/electric field sensitive equipment within 0.25 metres of the following
parts of the VSD system:

Variable Speed Drive (VSD)

EMC output filters

Input or output chokes/transformers

The cable between VSD and motor (even when screened/armoured)

Connections to external braking chopper and resistor (even when screened/armoured)

AC/DC brushed motors (due to commutation)

DC link connections (even when screened/armoured)

Relays and contactors (even when suppressed)
From experience, the following equipment is particularly sensitive and requires careful
installation.

Any transducers which produce low level analog outputs (<1V) , e.g. load cells, strain
gauges, thermocouples, piezoelectric transducers, anemometers, LVDTs

Wide band width control inputs (>100Hz)

AM radios (long and medium wave only)

Video cameras and closed circuit TV

Office personal computers

Capacitive devices such as proximity sensors and level transducers

Mains borne communication systems

Equipment not suitable for operation in the intended EMC environment, i.e. with
insufficient immunity to new EMC standards
to motor to motor
screened
VSD
VSD
f
f
PE PE
PE 0A 0D PE 0A 0D
Analogue Clean Earth
Dirty Earth
STAR POINT
110V
Control
Figure 10-2 Star Point Earthing
www.comoso.com
U-clip used to terminate screen
to motor
connection to the back panel
screened
VSD f
f
PE
0A 0D PE
PE
Digital Clean Earth
Incoming Safety Earth (PE)
Back Panel
PLC
Metal Work Earth
0D
Doors Back Metal
Panel Work
24V Control
unscreened signals
Signal/Control Screen
all screened signals not
going directly to a VSD
650G AC Drive