2 Engineering
2.4 Power connection
DS7 Soft starter 09/16 MN03901001Z-EN www.eaton.com 35
2.4 Power connection
The power section should be protected according to the connection form
used.
Cable and device protection on the supply side:
• Input AC… via standard fuses for cable protection or via motor-protective
circuit-breaker.
• Fuses in UL compliant systems must be UL-approved.
• The rated operating voltages of the fuses must be suitable for the local
mains voltage.
• No fuses are required on the motor side.
The following figure shows the basic connection of motor and power
section.
Figure 18: Connecting the power section and motor
F3 = optional semiconductor fuse
Q1 = Cable protection + motor protection
Q21 = Soft starter
M1 = Motor
At the output of the soft starter (terminals 2T1, 4T2, 6T3) you must not
• Connect any capacitive load (e.g. phase compensation capacitors),
• Connect several soft starters in parallel,
• Feed a mains voltage or a voltage from a variable frequency drive or other
voltage source.
M
3 ~
1L1
2L3
3
L5
1T2
2T4
3T6
L1
L2
L3
PE
Q1
Q21
F3
M1
I > I > I >
≦ 32 A
1L1
2L3
3L5
EP
EP
1T2
2T
4
3T6
Q21
≧ 41 A