Installation / Mounting; General Information - Siemens SIRIUS 3RW30 Manual

Installation / mounting

9.1

General information

General information
A motor feeder comprises a disconnector, a contact, and a motor as a minimum.
Line protection against short-circuits must be implemented, together with overload protection
for the line and motor.
Disconnector
The isolating function with line protection against overload and short-circuits can be achieved
with a motor starter protector or a fuse disconnector, for instance. The motor overload
protection function is integrated in the SIRIUS 3RW40 soft starter. The motor overload
protection for the SIRIUS 3RW30 soft starter can be implemented with a motor circuit
breaker, for instance, or using a motor overload relay in conjunction with a contactor (for the
fuse and motor starter protector assignment, refer to Technical data (Page 127)).
Contact
The contact function is taken care of by the SIRIUS 3RW30 or 3RW40 soft starter.
Hazardous voltage
Danger of death or serious injury.
If mains voltage is present at the input terminals of the soft starter, hazardous voltage may
still be present at the soft starter output even if a start command has not been issued. This
voltage must be isolated by means of a disconnector (open isolating distance, e.g. with an
open switch disconnector) whenever work is carried out on the feeder (refer to chapter Five
safety rules for work in or on electrical systems (Page 22)).
Note
All elements of the main circuit (such as fuses, motor starter protectors, and switching
devices) must be dimensioned for direct starting and according to the on-site short-circuit
conditions, and ordered separately.
For recommended fuse and motor starter protector ratings for the feeder with soft starter,
refer to chapter Technical data (Page 127).
SIRIUS 3RW30 / 3RW40
Manual, 10/2018, NEB535199502000/RS-AB/005
DANGER
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