Conductor clearances

[dwco]

All, I am looking for clearances for buss bars etc in a locomotive electrical cabinet. 600v.
We have a concern that the gap between the buss bars may be too close at .250 of an inch. These are the buss bars that cross over the contactors. Any help would be appreciated.

 

[dpc]

Don't know about locomotives, but typical 600 V bus spacing in most electrical distribution gear, etc is at least 32 mm.

0.25" sounds too tight, unless this is insulated?

Based simply on the dielectric strength of **dry** air, 0.25" is probably adequate for 600 V, but in practice this is too close.

 

[dwco]

Thanks!! It is our concern also. Dry air is one thing. Add a little dust & humidity.....

Thanks again!!
D

 

[dpc]

FWIW, you can use about 10 kV per inch for the dielectric strength of dry air.

You could check NEMA 480 V panelboard specs for something that might be roughly similar to what you are looking at.

Are you sure it isn't somehow insulated in between?