phase to phase NEC code clearance

M

mpwasco

Member
Location
oak Creek WI
Occupation
Project Manager
Please help!
looking for the code article that specifically states the 480volt air gap clearance that is required between phases...eg.....(between phase A and phase B).
Table 408.56 states "Live parts to ground"
any information pertaining to this required clearance would be appreciated.
 
don_resqcapt19 said:
Not sure there is anything in the code the supplies that information. That is more of a product design issue than an installation issue.
Click to expand...
This is correct. The NEC is not about designing equipment, that falls under ANSI, UL, etc.

UL 508 states as follows: "Between live parts of opposite polarity, 251-600V, Through air gap is 1", Over surface is 2". Between live parts and grounded metal parts, through air and over surface: 1". In reality though, ANSI specs for switchgear just calls out a testing standard, so as long as you pass the tests, it's good.
 
Last edited:
Jraef said:
This is correct. The NEC is not about designing equipment, that falls under ANSI, UL, etc.

UL 508 states as follows: "Between live parts of opposite polarity, 251-600V, Through air gap is 1", Over surface is 2". Between live parts and grounded metal parts, through air and over surface: 1". In reality though, ANSI specs for switchgear just calls out a testing standard, so as long as you pass the tests, it's good.
Click to expand...
Thank you, this helps a lot.
 
You must log in or register to reply here.
Top