transformer clearances

[don_resqcapt19]

They should have put the information from their comments directly in article 450.

How does Article 450 apply...the workspace rule is in Article 110

 

[Elect117]

I apologize. The full question was, What does the clearance have to be from the front of a transformer to a concrete wall in front of it?

As Don said, this question is still lacking in details.

Voltage to ground matters.

Concrete wall is considered condition 2 for table 110.26(A)(1).

So, in 90% of circumstances you are going to need to be 3'-6". Since 150V to ground does not cover many of the typically times you would install a transformer.

This is all, of course, neglecting the sections for over 1000V.

 

[jim dungar]

If the equipment is not installed with adequate working clearance then it cannot be maintained while energized, per most maintenance programs per NFPA 70E.

Isn't this a chicken or the egg issue?

 

[infinity]

How does Article 450 apply...the workspace rule is in Article 110

A section in the transformer article that states that the working space in Article 110 applies to transformers. Obviously the wording is needed based on the varying opinions on this thread.

 

[gene6]

If the equipment is not installed with adequate working clearance then it cannot be maintained while energized, per most maintenance programs per NFPA 70E.

Isn't this a chicken or the egg issue?

Yeah exactly when I questioned the the new no energized work over 300V safety policy they told me that the one thing every electrical incident in the last 50 years had in common was open energized 480/277 or higher voltage equipment, including a outside contractor doing an IR scan unfortunately so reducing when these things can be opened while energized is a new management priority, and that is difficult for me to get used to.