2 Engineering
2.7 Residual current circuit-breaker (RCD)
DS7 Soft starter 09/16 MN03901001Z-EN www.eaton.com 37
2.7 Residual current circuit-breaker (RCD)
Residual current circuit-breakers – also referred to as RCDs (residual current
devices) and ground fault circuit interrupters (GFCIs) – protect people and
livestock from the presence (not the production!) of impermissibly high
touch voltages. They prevent dangerous and fatal injuries caused by
electrical accidents and also serve as fire prevention.
Size 1 and 2 soft starters of the DS7 series have no connection to the earth
potential (PE). In size 3 and 4, the DS7 soft starters have an exposed heat
sink which must be connected with the earth potential (PE).
When using a DS7 soft starter, there is no leakage current at the motor
feeder. Standard residual current circuit breakers (RCD part no. A) up to
30 mA can be used.
Figure 19: Motor feeder with RCD
F1 = Residual current circuit breaker (RCD)
F3 = optional semiconductor fuse
Q1 = Cable protection + motor protection
Q21 = Soft starter
M1 = Motor
M
3 ~
1L1
2L3
3
L5
1T2
2T4
3T6
L1
L2
L3
PE
Q1
RCD
Q21
BG1, BG2
F1
F3
M1
I > I > I >
1L1
2L3
3
L5
1T2
2T4
3
T
6
BG3, BG4
PEPE
To Next Page
Loading...
