Voltage limitation on Underground Cables at Mine Sites?

[majesus]

Pennsylvania Bureau of Deep Mine Safety has a voltage restriction on underground transmission at mines:
"Secondary or underground transmission voltage shall not exceed fifteen thousand volts, nominal, phase-to-phase. "

http://www.dep.state.pa.us/dep/deputate/minres/dms/website/approval/minepower.html

Does anyone know if the larger national governing bodies such as OSHA, MSHA, NEC and even CSA has a voltage limitation for transmitting power via underground cables at mines?

I did look through
CSA M421-00 Use of Electricity in Mines,
CSA C22 No 96.1-04 Mine power feeder cables
and OSHA and MSHA websites.

Didn't find anything particular on this subject underground transmission cables.

 

[gepman]

This should be covered in MSHA Chapter 57 Subpart K. This available at

http://www.msha.gov/30cfr/57.0-1.htm

I didn't see any voltage restrictions of the nature that you mentioned.

 

[CoryA]

I too am unaware of any such regulation. I did as you did majesus and looked through my copy of CSA M421-00 Use of Electricity in Mines - I found nothing.

I understand that there are many coal mines in that region - in that regard a limitation on voltage seems to make sense. It seems to me that fifteen thousand volts, however, would be more than sufficient to ignite stray coal dust.

I did find the following document on the MSHA website, but it only very briefly discusses the amount of electricity needed for coal dust ignition.

http://www.msha.gov/S&HINFO/TECHRPT/FANDE/CDUSTEX.pdf

---
Cory Anderson

http://startco.ca/