Repair And Maintenance Switch - Eaton DS7 Manual

2.11.13 Repair and maintenance switch

Repair and maintenance switches disconnect all the poles (all the phases) in
the connection cable to a motor. This prevents voltage from being applied
and the motor from being started by accident during repair and maintenance
work.
The DS7 soft starter has a two-phase circuit with semiconductor elements in
the power section, one phase is always connected through directly.
DANGER

In both the disabled and stop states of the soft starter when the
mains voltage is present (terminals 1L1, 3L2, 5L3), there is also
a dangerous voltage present at the output terminals (2T1, 4T2,
6T3) and therefore also on the motor cables and connection
terminals of the motor (U, V, W)!
1L1 3L2
2T1 4T2
M
3 ~
Size 1 and 2 (4 - 32 A)
Figure 33: Dangerous voltage
Because of this, all the poles (all three phases) in two-phase controlled soft
starters should always be disconnected from mains voltage in the stop state
– with a contactor connected in series on the mains side, for example.
If a control system does not provide this potential isolation, it is advisable
to connect the motor through a repair or maintenance switch.
DS7 Soft starter 09/16 MN03901001Z-EN www.eaton.com
5L3
6T3
Size 3 and 4 (41 – 200 A)
2 Engineering
2.11 Motor connection
1L1 3L2 5L3 PE
2T1 4T2 6T3 PE
M
3 ~
51