Siemens UL 508A Довідковий посібник - Сторінка 13

Переглянути онлайн або завантажити pdf Довідковий посібник для Промислове обладнання Siemens UL 508A. Siemens UL 508A 30 сторінок.

Basic steps for calculating the SCCR of a control

panel

4.1

SB4.2 – Determining the short-circuit current ratings (SCCR) of

individual power circuit components

The short-circuit strength of individual power circuit components can be calculated using

three possible methods:

● Based on device markings or component instruction sheets

● Based on assumed short-circuit current rating

● Based on tested combinations of devices according to UL508

4.1.1

Most Siemens power control and circuit protection components include a standard short

circuit rating on the front or on the nameplate.

Example of marking on a 3RT contactor

Figure 4-1

Exception

The short-circuit current rating of Siemens frequency converters is stated in the operating

instructions or the relevant catalogs. This complies with the requirements of NEC Article 409

and is therefore entered in the relevant UL test reports.

Moreover, in the case of frequency converters that are protected with fuses, circuit breakers

according to UL489 or self-protected combination motor controllers per UL508 type E, the

short-circuit current rating of the drive in conjunction with the line-side protective device is

stated.

Short-circuit current rating (SCCR) of industrial control panels

Reference Manual, 06/2013, A5E31896849002A/RS-AA/001

Nameplate