Parker 650V series, Техническое руководство

Страница: 112 / 135

10-4
Certification for the Drive
650V AC Drive
Single VSD -
Single Motor
Apply a single point
series earthing
strategy for a single
VSD mounted in a
cubicle as shown.
The protective earth
connection (PE) to
the motor must be
run inside the
screened cable
between the motor
and VSD and be
connected to the
motor protective
earth terminal on the
VSD.
Single VSD - Multiple Motors
Note: Refer to Chapter 11: “Application Notes” - Using Multiple Motors on a Single Drive.
If connecting multiple motors to a single VSD, use a star junction point for motor cable
connections. Use a metal box with entry and exit cable glands to maintain shield integrity.
Refer to Chapter 11: Application Notes” - Using Multiple Motors on a Single Drive.
Star Point Earthing
A star-point earthing policy separates ‘noisy’ and ‘clean’ earths. Four separate earth busbars
(three are insulated from the mounting panel) connect to a single earth point (star point) near the
incoming safety earth from the main supply. Flexible, large cross-section cable is used to ensure
a low HF impedance. Busbars are arranged so that connection to the single earth point is as short
as possible.
1 Clean Earth Busbar (insulated from the mounting panel)
Used as a reference point for all signal and control cabling. This may be further subdivided into
an analog and a digital reference busbar, each separately connected to the star earthing point.
The digital reference is also used for any 24V control.
Note: The 690V uses a single clean earth busbar for analog and digital.
2 Dirty Earth Busbar (insulated from the mounting panel)
Used for all power earths, i.e. protective earth connection. It is also used as a reference for any
110 or 220V control used, and for the control transformer screen.
3 Metal Work Earth Busbar
The back panel is used as this earth busbar, and should provide earthing points for all parts of the
cubicle including panels and doors. This busbar is also used for power screened cables which
terminate near to (10cm) or directly into a VSD - such as motor cables, braking choppers and
their resistors, or between VSDs - refer to the appropriate product manual to identify these. Use
U-clips to clamp the screened cables to the back panel to ensure optimum HF connection.
4 Signal/Control Screen Earth Busbar (insulated from the mounting panel)
Used for signal/control screened cables which do not go directly to the VSD. Place this busbar
as close as possible to the point of cable entry. ‘U’ clamp the screened cables to the busbars to
ensure an optimum HF connection.
VSD
Back Panel
Cubicle
Motor
AC Supply
U-clip used to
terminate screen
connection to
the back panel
Armoured/screened cable
As short as possible
(0.3 metres maximum)
External
Filter
PE2 PE1
Additional PE connectors for
where PE1 is <10mm cross-section
2
Figure 10-1 EMC and Safety Earthing Cabling