Parker AC30 series, User Manual

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C-11
Compliance
AC30 series Variable Speed Inverter
EMC Installation Guidance
PROTECTIVE EARTH (PE) CONNECTIONS
Local wiring regulations take precedence and may require the protective earth connection of the motor to be connected locally, i.e. not
as specified in these instructions. This will not cause shielding problems because of the relatively high RF impedance of the local earth
connection.
Earthing
A star-point earthing policy separates ‘noisy’ and ‘clean’ earths. Four separate earth bus bars (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 low HF impedance. Bus bars are arranged so that connection to the single earth point is as short as possible.
1. 0V/Signal Grounding
The “0V/signal ground” is required to be separately earthed, for multiple products these terminals should be connected together at a single,
local earthing point.
2. Control/Signal and Encoder Cables
Control/signal and encoder cables, all analogue inputs, and communications require screening with the screen connected only at the VSD
end. However, if high frequency noise is still a problem, earth the screen at the non-VSD end via a 0.1  F capacitor. Connect the screen (at
the VSD end) to the VSD protective earth point and not to the control board terminals.
3. 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.
4. 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.
5. 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.
6. 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 busbar to ensure an optimum HF connection.