Dinverter
A
User Guide
Issue code: d2au9
38
Routine EMC precautions (Figure 4–8)
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/MCB.
8
Motor-frame ground connection, if required.
Routine EMC precautions
9
Use four-core cable to connect the motor to the Drive as shown. The
ground conductor in the motor cable must be connected only to the
ground terminals of the Drive and motor; it must not be connected
directly to the power-ground bus-bar.
10
If the wiring for sensitive signal circuits is to be parallel to an unshielded
motor cable (or cables for an unfiltered power supply) for more than
1 metre (3 feet), ensure the separation is at least 0.3m (12 in).
If the parallel run is to exceed 10 metres (30 feet), increase the
separation proportionally. For example, if the parallel run is to be
40 metres, the spacing must be 0.3 x 40
÷
10 = 1.2 metres.
When a motor-thermistor is used, this constraint does not apply to the
cable connecting the thermistor to the Drive. The motor-thermistor
cable must be shielded (as shown in Figure 4–14).
11
Do not place sensitive signal circuits in a zone extending 0.3m (12 in) all
around the Drive.
12
If the control circuit 0V is to be grounded, this should be done at the
system controller (eg. PLC) and not at the Drive. This is to avoid
injecting noise currents into the 0V circuit.
