Unidrive
LV
model sizes 1 to 3 Installation Guide
Issue code: uliu1
Installing the Drive 2-33
General features
1. Single power ground bus-bar or low-impedance
ground terminal.
2. Incoming
AC supply ground connected to the
power ground bus-bar.
3. Connect grounds of any other circuits to the
power ground bus-bar.
4. Site ground if required.
5. Metal back-plate, safety bonded to the power
ground bus-bar.
6. System isolator, circuit contactors and
fuses/MCB.
7. Alternative position for Drive fuses.
8. Optional braking resistor mounted externally,
protected and shielded by a metal grille.
9. Thermal overload device to protect the
braking resistor.
10. Alternative safety ground for the motor.
11. Motor-frame ground connection, if required.
Special features for EMC
12. Drive heatsink directly grounded to the
back-plate using the metal mounting-brackets.
Ensure that the screws make direct electrical
connection to the back-plate, for example by
using screw threads tapped in the backplate.
13. RFI filter mounted at the side of the Drive.
Ensure a separation of 5 to 10mm (
1
/
4
to
3
/
8
in)
from the Drive. The RFI filter casing is directly
grounded to the back-plate by the fixing
screws.
14. A shielded (screened) or steel-wire armoured
cable must be used to connect the Drive to the
motor. The shield must be bonded to the
back-plate using an uninsulated metal cable-
clamp. The clamp must be positioned no
further than 100mm (4 in) from the Drive.
15. Connect the shield of the motor cable to the
ground terminal of the motor frame using a link
that is as short as possible and not exceeding
50mm (2 in) in length. A full 360° termination
of the shield to the terminal housing of the
motor is beneficial.
16. Ensure the
AC supply and ground cables are at
least 100mm (4 in) from the Drive.
17. Avoid placing sensitive signal circuits in a zone
extending 0.3m (12 in) all around the Drive.
18. Unshielded wiring to the optional braking
resistor(s) may be used, provided the resistor is
either in the same enclosure as the Drive or the
wiring does not run external to the enclosure.
When the braking-resistor wiring is unshielded,
ensure a minimum spacing of 0.3m (12 in) from
signal wiring and the
AC supply wiring to the
RFI filters.
19. If the control circuit 0V is to be grounded, this
should be done at the host controller (eg. PLC)
and not at the Drive. This is to avoid injecting
noise currents into the 0V circuit.
Compliance with EMC emission standards (model sizes 1 and 2)