Ampacity ratings residential remodel - new code versus existing

[sparky23]

Thanks in advance

looking at 1950's era house - need to confirm that new work in place must meet current code or match code that structure was originally built.


Also would like to confirm---
NEC 2008
310.16 and 334.80 limit NM TypeB (Romex) to 60-degree
these are not de-rated for temperature location or installtion.

50A 6ga (55A rating on 6ga)
40A 8ga
30A 10ga

does the new wire have to meet new code or the code it was constructed under?

 

[infinity]

The NEC is not retroactive. Some places do not even adopt the NEC so you would need to know the code that was adotped at the time of installation.

 

[sparky23]

thanks

 

[jim dungar]

New work often needs to meet the current codes.
Existing work is usually allowed to remain as is.
Rework/modification of existing work (i.e. replacing the conductors between an existing switch box and an existing lighting outlet) may need to meet current codes.

 

[sparky23]

interesting and becomes complicated for inspectors...
for example - -which side of junction box does he look at? ( I know what happens in my jurisdiction - inspects what they see or permitted but reserve the right to look further.....)
however for example - not my job but plausible...
"I only added the one new receptacle - grabbing power from nearest source..."
this could run project costs up.....

Can you tell where in the NEC it might say the NEC is not intended to be applied "retroactively"?

thanks again