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Ground wire (terminal 95) of at least 10 mm
2
(8 AWG) cross-section.
2 separate ground wires both complying with the dimensioning rules.
See EN/IEC 61800-5-1 and IEC EN 62477-1 for further information.
10.11.1 Using a Residual Current Device (RCD)
Where residual current devices (RCDs), also known as earth leakage circuit breakers (ELCBs), are used, comply with the following:
Use RCDs of type B only, which are capable of detecting AC and DC currents.
Use RCDs with an inrush delay to prevent faults caused by transient ground currents.
Dimension RCDs according to the system configuration and environmental considerations.
The leakage current includes several frequencies originating from both the mains frequency and the switching frequency. Whether
the switching frequency is detected depends on the type of RCD used.
e
3
0
b
b
9
5
8
.1
2
Leakage current
Frequency
3
rd
harmonics
Mains
Cable
RCD with low f
cut-off
RCD with high f
cut-off
50 Hz
150 Hz
f
sw
Illustration 77: Mains Contributions to Leakage Current
The amount of leakage current detected by the RCD depends on the cut-off frequency of the RCD.
e3
0b
b9
57
.1
2
Leakage current [mA]
100 Hz
2 kHz
100 kHz
Illustration 78: Influence of Cut-off Frequency of the RCD on what is Responded to/Measured
For more details, refer to the RCD Application Note.
AJ300847815559en-000101 / 130R0337 | 143
Danfoss A/S © 2020.09
Electrical Installation
Considerations
VLT® AQUA Drive FC 202
Design Guide