,QVWDOODWLRQ
#
3URFHGXUH
##
6056
953#
9HFWRU
#
'ULYH
#0#
+$
7968;7
50VAC capacitor. The motor protective earth should be connected to the drive module motor protective earth
connection.
If a shielded cable is not available, lay unshielded motor cables in a metal conduit which will act as a shield. The
conduit must be continuous with a direct electrical contact to the drive module and motor housing. If links are
necessary, use braid with a minimum cross sectional area of 10 mm
2
.
Safety earthing always takes precedence over EMC earthing.
The use of screened cable without an EMC filter is not recommended, as line-conducted interference will
increase substantially and the capacitive coupling of the output cable to earth will result in high earth-leakage
currents.
To ensure the correct operation of the 620 drive module, some control and signal cables (encoder, all analogue
inputs and communications) have to be screened back to the inverter terminals. The screen integrity must be
continuous right back to the drive if not connected to the cubicle. Always minimise the length of screen stripped
back to make this connection. The screen should only be connected at the drive end. If high frequency noise is
still a problem, earth at the non drive end via a 0.1
µ
F capacitor.
6FUHHQLQJ
#
DQG
#
(DUWKLQJ
#
:KHQ
#
0RXQWHG
#
LQ
#
DQ
#
(QFORVXUH
Make sure the requirements of EN60204 are adhered to with electrical equipment for machines. Satisfactory
EMC performance is only achievable when the 620 drive module, filter and associated equipment is mounted on
a conducting metal mounting panel. Beware of constructions using insulating mounting panels or undefined
mounting structures A single point earthing strategy should be followed for a single drive module mounted in an
enclosure as shown in figure 3-11. The protective earth connection (PE) to the motor must run inside the
screened cable between the motor and 620 drive module, where it is to be connected to the motor protective earth
terminal on the drive module. (Note in accordance with EN60204 only one protective earth conductor is
permitted at each earth terminal contacting point). Local wiring regulations may require the protective-earth
connection of the motor to be connected locally but this will not cause shielding problems due to the relatively
high RF impedance of the local earth connection.
AC
Supply
Filter
Motor Cable Screen
Motor
Safety
Earth
PE
PE
PE
AC/DC
PE
As short
as possible
)LJ
1#6044=#
6FUHHQLQJ
#
DQG
#
HDUWKLQJ
#
RI
#
D
#
VLQJOH
#953#
GULYH
#
PRGXOH
1
When more than one piece of electrical equipment is fitted inside an enclosure, care must be taken to ensure that
noise flowing in the earth connection does not couple into other equipment. A star-point earthing policy
separating noisy from quiet earths is strongly recommended. Five separate earths branches should be provided
for:
♦
Clean earth busbar
The Clean earth busbar is used as a reference point for all signal and control cabling. This
may the further subdivided into an analogue and a digital reference busbar, each separately
connected to the star earthing point. The digital reference is also used for any 24V control.
♦
Dirty earth busbar
The dirty earth busbar is used for all power earths (i.e. protective earth connections)
This manual was downloaded on www.sdsdrives.com
+44 (0)117 938 1800 - info@sdsdrives.com