I want to replace a 200A breaker with a 100A breaker in a 200A Milbank meter main and use it as service equipment for a 100A service. The meter main is a combo overhead and underground. The utility wants 200A rated service equipment for underground. My question is can I change this breaker without voiding the UL rating? Opinions please.
UL listing question
- Thread starter elecmen
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petersonra
Senior Member
- Location
- Northern illinois
- Occupation
- Semi-retired engineer
Are these things even listed?
Was told by my supply house rep that talked to someone at Milbank when I tried to order the 200A metermain with a 100A breaker that he couldn't custom order it with a 100A breaker because of the UL listing.
What did the mianufactture, milbaankk, say. Aren't they the onen that ,UL listed it? I would like to think that they would give you a straight answer..
mgookin
Senior Member
- Location
- Fort Myers, FL
- Occupation
- Retired inspector, plans examiner & building official
Sounds like they got their listing with the 200A breaker as part of the assembly. If they had not included the breaker, the listing could have included a provision "... OCPD not to exceed 200A".
Can you find one you can buy with no OCPD and then buy that separate?
In addition have you considered NEC art 110-2 where the AHJ blesses it?
Where is the service point?
Around here, most in-city laterals are under the control of the POCO, as the service point is the line side terminals of the meter (or meter-main). If the POCO demands 200A equipment, that means you are getting a 200A-rated service per POCO design standards, regardless of what you or the HO requested.
Around here, most in-city laterals are under the control of the POCO, as the service point is the line side terminals of the meter (or meter-main). If the POCO demands 200A equipment, that means you are getting a 200A-rated service per POCO design standards, regardless of what you or the HO requested.
kwired
Electron manager
- Location
- NE Nebraska
- Occupation
- EC
I don't know enough about what Milbank all offers, only about two units that are commonly used around here - both with 200 amp main breakers.
If they make a 100 amp breaker in same frame size - it probably is listed to take it.
It may also cost less to just get the unit that has the 200 amp main plus spaces for branch breakers and put a 100 amp breaker in one of those positions.
If they make a 100 amp breaker in same frame size - it probably is listed to take it.
It may also cost less to just get the unit that has the 200 amp main plus spaces for branch breakers and put a 100 amp breaker in one of those positions.
What it appears as though you are suggesting is to use a 100at breaker as. Main to feed the panel which is a good option but don't forget that hold-down kit. I believe that it will pass.
What it appears as though you are suggesting is to use a 100at breaker as. Main to feed the panel which is a good option but don't forget that hold-down kit. I believe that it will pass.
But you may not be able to use the space across from it but that probably won't be an issue anyway.
I know with SQAURE-D meter main combo service panels, I can take a 200A rated main panel that comes with a preinstalled 200A main breaker and replace the breaker with a lower one (100A or 125A). I have done this many times without any issue from POCO or AHJ.
kwired
Electron manager
- Location
- NE Nebraska
- Occupation
- EC
With situation I described there is still 200 amp main in the meter/main but it also has 8 poles for branch breakers - I was suggesting to plug a 100 amp breaker onto two of these spaces. Nothing is being "back-fed" so no hold down kit is necessary.
AHJ approval is all that is required regardless of the finer points of Code compliance.
However, to be Code compliant, service equipment is required to be listed [230.66]. For a listed meter-main to retain its listing when its parts are changed in the field, those parts must be included in the documentation as optional equipment.
That amounts to having a 200A service (or thereabouts as Code permits). Service conductors ahead of the meter-main, under NEC purview, must have an ampacity greater than both the calculated load and the next lower standard OCPD rating [175A]... or qualify under 310.15(B)(7).
Under this scenario, we are back to my earlier post about location of the service point. If it is ahead of the meter-main line-side terminals, then the above applies to the supply conductors.
Then, what is the purpose of the 100a breaker, a feeder for something? I thought that the 200a breaker was too large and the goal was to replace it with a 100a.
kwired
Electron manager
- Location
- NE Nebraska
- Occupation
- EC
OP apparently only wants 100 amp feed into the place for whatever reason, but POCO only supplies them with 200 amp conductor. Somehow he needs a meter socket that will accept a 200 amp conductor but also needs 100 amp overcurrent protection for whatever he is feeding.
When I run into this situation I usually have a stand alone 200 amp meter socket and then a separate 100 amp main - but don't know what restrictions OP may have on what can and can't be used (some POCO's only allow certain specific metering equipment).
mgookin
Senior Member
- Location
- Fort Myers, FL
- Occupation
- Retired inspector, plans examiner & building official
I like the previous suggestion of building the 200A service and then go to a panel with a 100A branch. Use that branch to do whatever he needs to do even if it means feeding another panel.
Good solution.
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