SER ampacity

[electricalperson]

we have some 2/4 SER cable thats marked XHHW insulation on the outer covering. is this used as a 60 degree cable or 75?

 

[TOOL_5150]

we have some 2/4 SER cable thats marked XHHW insulation on the outer covering. is this used as a 60 degree cable or 75?

what code cycle are you using.

~Matt

 

[480sparky]

UL White Book ZKST:

XHH --Indicates a single conductor having a cross-linked synthetic polymer insulation with no overall covering provided, rated 90?C dry.

XHHW -- Indicates a single conductor with the same description as Type XHH, except that it is rated 90?C dry, 75?C wet.

 

[TOOL_5150]

UL White Book ZKST:

But he is not using a single conductor..

~Matt

 

[480sparky]

But he is not using a single conductor..

~Matt

I don't use single conductors when I install NM, either.

 

[izak]

yeah, well.... i build services all the time with #12 lamp cord
some bone head on this site tried to tell me it wouldnt work, but ive been useing lamp cord for years.

if you need more amps, just add another peice of cord, or (three or ten) twist the ends together, and PRESTO!

you have one larger wire,


if any of you have a problem with this post, then you probably have ALOT better reason to be on this website than I do.



all in good fun
(or whatever i call it)

 

[TOOL_5150]

I don't use single conductors when I install NM, either.

depending on the code cycle - nm is 60 degree though.

~Matt

 

[Dennis Alwon]

we have some 2/4 SER cable thats marked XHHW insulation on the outer covering. is this used as a 60 degree cable or 75?

If used as a feeder SER must be rated 60C in the 2008 if it is installed indoors. If you are using the 2005 or earlier code than 75C is what you use.

 

[480sparky]

depending on the code cycle - nm is 60 degree though.

~Matt

That's my point.... NM is not a single conductor, but the conductors withing at least have some construction specs.

 

[augie47]

Unfortunately, In TN it now depends on what area you are doing the install. Some areas are on '05, thus 75?, some on '08, thus 60?, and even in the '08 areas some inspectors are enforcing it one way, some another.

 

[electricalperson]

thank you guys. im using the 2008 code cycle. i didnt have my code book handy i left it in the van.

 

[gndrod]

-2

-2

we have some 2/4 SER cable thats marked XHHW insulation on the outer covering. is this used as a 60 degree cable or 75?

Check to see if the conductors are -2 type that allows 90C rate for both WET or Dry.

 

[iwire]

Check to see if the conductors are -2 type that allows 90C rate for both WET or Dry.

There are almost no instances where we can use the 90 C rating of SE regardless of it being XHHW-2 or not.

With the changes in the 2008 NEC SE used as indoor feeder or branch circuit conductors is limited to the 60 C rating.

Used as service entrance conductors we are limited to 75 C rating due to the rating of the devices it will connect to.

 

[gndrod]

SE vs. XHHW-2

SE vs. XHHW-2

There are almost no instances where we can use the 90 C rating of SE regardless of it being XHHW-2 or not.

With the changes in the 2008 NEC SE used as indoor feeder or branch circuit conductors is limited to the 60 C rating.

Used as service entrance conductors we are limited to 75 C rating due to the rating of the devices it will connect to.

Thanks Bob, I was using an earlier Southwire cutsheet based on SE cable 90C ambient operating base wet or dry (above ground) and not the conductor allowed ampacity 75C rate for XHHW-2 conductors in the SE cable.

 

[eljefetaco]

you keep referencing nm does the 60 degree also apply to rx when ampacity is involved?

 

[Dennis Alwon]

you keep referencing nm does the 60 degree also apply to rx when ampacity is involved?

Yes read 334.80

 

[electricalperson]

you guys are great

 

[LarryFine]

you guys are great

Flattery'll get you everywhere. :grin: