Siemens UL 508A Reference Manual - Page 5
Browse online or download pdf Reference Manual for Industrial Equipment Siemens UL 508A. Siemens UL 508A 30 pages.
Print PageTable of contents
1
Introduction ............................................................................................................................................. 7
2
Overview of NEC Article 409 ................................................................................................................... 9
3
Overview of Supplement SB from the UL 508A standard ....................................................................... 11
4
Basic steps for calculating the SCCR of a control panel ......................................................................... 13
4.1
components .................................................................................................................................. 13
4.1.1
Basic: Device markings or component instruction sheets ........................................................... 13
4.1.2
Basic: Assumed short-circuit current rating ................................................................................. 14
4.1.3
Basic: Tested combination of devices according to UL508 ......................................................... 14
4.2
through currents when using current-limiting devices in the feeder circuit .................................. 18
4.2.1
Current-limiting transformers ....................................................................................................... 18
4.2.2
Current-limiting circuit breakers (according to UL489) ................................................................ 18
4.2.3
Current-limiting fuses ................................................................................................................... 20
4.3
SB4.4 - SCCR calculation of the industrial control panel ............................................................ 23
5
Flow chart for calculating the SCCR of a component ............................................................................. 25
5.1
according to UL 508A SB4.2 ........................................................................................................ 25
5.2
Calculation of the short-circuit current rating of current-limiting feeder components .................. 26
5.3
UL 508A Supplement SB 4.4 ....................................................................................................... 28
Short-circuit current rating (SCCR) of industrial control panels
Reference Manual, 06/2013, A5E31896849002A/RS-AA/001
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