Sccr Label

[mbarry]

When labeling control panel per UL508A, the label shall include short circuit: __ka and voltage ___ maximum.
Question is, should the voltage on the label be the rated voltage of components or the voltage for the panels intended use?
For instance all components in power circuit are rated 25ka @ 600v, but panel is intended for use in 230v application. Should SCCR label read 230v or 600v?
thank you,

 

[jim dungar]

When labeling control panel per UL508A, the label shall include short circuit: __ka and voltage ___ maximum.
Question is, should the voltage on the label be the rated voltage of components or the voltage for the panels intended use?
For instance all components in power circuit are rated 25ka @ 600v, but panel is intended for use in 230v application. Should SCCR label read 230v or 600v?
thank you,

The voltage should be the one at which the SCCR was calculated.

The SCCR oftens varies with voltage. Ideally the SCCR was calculated at the utilization voltage, in this case 240V. It is also not uncommon for multiple SCCR and voltages to be listed (i.e. 65kA @240V and 18kA@ 480V).

 

[cschmid]

can I ask where you acquired the UL508a and supplement B? I would like to get a copy of it..When multiple SCCR ratings are present are we required to use the SCCR rating on the devices for the voltage we built the panels for? also if the devices SCCR rating is of higher voltage than we are using is it still valid to use?