Adjustable trip breakers or trip plugs

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kjrise

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I have a inspector saying that the wire size needs to match the breaker frame size not adjustable trip setting. Is is also saying this on breakers with removable trip plugs.
Example a 400amp frame breaker with a 250amp trip unit.
Can anyone point me to the right code section to dispute this?
Thanks
 
I have had inspectors require Max fuse size xxx labeled on fusible disconnects if smaller wire and fuses are used, which is a reasonable request. Don't know of anywhere in the code that requires it or prohibits it. It is just a personal opinion of the inspector I believe, make him cite the code section that it violates.
 
hillbilly1 said:
I have had inspectors require Max fuse size xxx labeled on fusible disconnects if smaller wire and fuses are used, which is a reasonable request. Don't know of anywhere in the code that requires it or prohibits it. It is just a personal opinion of the inspector I believe, make him cite the code section that it violates.
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So if a peice of equipment requires a 70a max fuse, he'd require 100a fuses just because it's a 100a disco?:confused:
 
kjrise said:
I have a inspector saying that the wire size needs to match the breaker frame size not adjustable trip setting. Is is also saying this on breakers with removable trip plugs.
Example a 400amp frame breaker with a 250amp trip unit.
Can anyone point me to the right code section to dispute this?
Thanks
Click to expand...


by that logic, 20amp branch circuits should be run with #2 since someone could replace the breaker with a larger one, just as someone could replace a trip plug.... :confused:
 
hillbilly1 said:
No, you could use the 70 amp fuses, you would just have to label the front of the disconnect "70 amp Max fuse" The wire size could remain for the 70 amp size.
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Have you asked for a Code reference to back that up?

Here's one for the inspector: 90.1(C). If the next person can't figure out that the disconnect goes to the equipment and fails to understand the equipments' label, correlate that to the fuses and wire size, then he/she shouldn't be doing electrical.
 
Is this inspector wet behind the ears ? Do you have engineered stamped and approved drawings showing the frame/trip/wire sizes ? ( I am very interested in the outcome of this)
 
480sparky said:
Have you asked for a Code reference to back that up?

Here's one for the inspector: 90.1(C). If the next person can't figure out that the disconnect goes to the equipment and fails to understand the equipments' label, correlate that to the fuses and wire size, then he/she shouldn't be doing electrical.
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It wasn't an unreasonable request, even if he could not prove it. Something minor like that is not worth getting in a ........... tizzy about.
 
hillbilly1 said:
It wasn't an unreasonable request, even if he could not prove it. Something minor like that is not worth getting in a ........... tizzy about.
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True. But a lot of little stuff adds up to big stuff. What else is he allowed to 'get away with'? Are NEMA 3R discos required to have WP/UV-resistant labels then? How much do those cost?

"A million dollars here, a million dollars there, and pretty soon, you're talking about real money"
 
kjrise said:
I have a inspector saying that the wire size needs to match the breaker frame size not adjustable trip setting. Is is also saying this on breakers with removable trip plugs.
Example a 400amp frame breaker with a 250amp trip unit.
Can anyone point me to the right code section to dispute this?
Thanks
Click to expand...
Have you read 240.6(C)?
 
Like jim said:

kjrise said:
(cut)Can anyone point me to the right code section to dispute this?
Thanks
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The inspector is likely looking at (2002) 240.6.B. Although I have never heard of a rating plug being called "adjustable trip".

If this is so, see if you qualify for 240.6.C, "restricted access". It's generally pretty easy to meet one of the three.

cf
 
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Cold Fusion said:
Like jim said:


Although I have never heard of a rating plug being called "adjustable trip".

cf
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I agree. Does this qualify as an adjustable trip CB?

Rob%27s%20Work%20006.JPG
 
infinity said:
(cut) Does this qualify as an adjustable trip CB? (cut)
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I think so. As I recall, GE Micro VersaTrip is programmable to a percentage of the rating plug.

I had translated the OP as saying the CB had a rating plug, but no adjustable trip. As we all know, this is pretty common on molded case CBs.

cf
 
Cold Fusion said:
I think so. As I recall, GE Micro VersaTrip is programmable to a percentage of the rating plug.

I had translated the OP as saying the CB had a rating plug, but no adjustable trip. As we all know, this is pretty common on molded case CBs.

cf
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That is correct, the MVT series trip units can be adjusted for LTPU down to 0.5 (And up to 1.0) of the rating plug. (Also has ST, INST, and GF functions available with different ranges but that has nothing to do with the question so we will skip those).

I agree with your translation of the OP also.
 
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