Siemens 3RK1308‑0 00‑0CP0 Series Equipment Manual page 60

Product features
5.8 Operating motor starters
Example of the correct engineering of a motor starter
NOTICE
Maximum current-carrying capacity
Note that the sum of the starting current of the motor and the inrush current of the brake
must not exceed the maximum current-carrying capacity of the selected motor starter.
● Rated motor current I
● Braking current I
● Setting value on motor starter: I
● Motor starting current factor: I
● Brake inrush current factor: 8-fold
● Motor starting current: I
● Maximum brake inrush current: I
● Motor starting current + brake inrush current: 19.6 A + 4 A = 23.6 A
● Maximum current-carrying capacity of 3 A motor starter (3RK1308 - 0AC00-0CP0): 30 A;
see also data sheet (https://support.industry.siemens.com/cs/ww/en/ps/21800/faq
(https://support.industry.siemens.com/cs/ww/en/ps/21800/faq))
● Result: The maximum current-carrying capacity is 23.6 A. It is below 30 A for this
application. This means that you can use the ET 200SP motor starter
(3RK1308 - 0AC00-0CP0) for this application.
Operation by experienced users only
Qualified personnel required
All work involved in connecting, commissioning, operation and maintenance must be
carried out by qualified, responsible personnel.
Failure to follow proper procedures may result in personal injury and damage to property.
60
: 2.45 A
rated
: 0.50 A
B
St
WARNING
= I + I = 2.95 A
e rated B
/I 8-fold
St rated
= I * I /I = 2.45 A * 8 = 19.6 A
rated St rated
* 8 = 0.5 A * 8 = 4 A
B
Equipment Manual, 11/2019, A5E34821005002A/RS-AC/003
Motor starter (3RK1308‑0**00‑0CP0)