NEC Art 110 Clearance for 750VDC

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Point8

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Houston, Texas
I have a electrical building with a battery rack on one side (125VDC batteries) and a 750VDC Switch on the other side. What is my electrical clearance required? Condition 2 since the battery rack is grounded. Use the Med voltage table for 750VDC - 4ft ????

Thanks in advance for any help. I deal almost exclusively with AC except for battery systems.
 
Point8 said:
I have a electrical building with a battery rack on one side (125VDC batteries) and a 750VDC Switch on the other side. What is my electrical clearance required? Condition 2 since the battery rack is grounded. Use the Med voltage table for 750VDC - 4ft ????

Thanks in advance for any help. I deal almost exclusively with AC except for battery systems.
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Table 110.34(A) is the correct table to use, and 4 ft is correct. It is nominal voltage-to-ground that matters, so unless the battery bank is center-grounded (which is rare), the 750Vdc governs. This is the case if either polarity is grounded or if it is completely ungrounded.
 
750VDC Clearance

750VDC Clearance

Thanks for getting back to me.
The 750VDC gear is not grounded in this application. These type buildings power the trains like in Portland Oregan and Seattle. The color is epoxy and walls are insulated due to the equipment not grounded.
 
Carultch was spot on. You should be aware that Voltage to Ground is a defined term in Article 100.
 
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