electrofelon
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Does anyone know where I can find them? Or perhaps they dont have any? Only was able to pull up their two tier ratings on the web.
Siemens three tier series ratings
- Thread starter electrofelon
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electrofelon
Senior Member
- Location
- Cherry Valley NY, Seattle, WA
I dont believe that is allowed. I think people (incorrectly) do it all the time though. See the last bullet on page three of this:
http://web.eaton.com/ecm/idcplg?IdcService=GET_FILE&dID=4796305
I don't know why, but I was thinking about selective coordination combinations when I posted that. Not series ratings.
They do list table 13 which includes triple ratings - but that looks like a pretty short table.
I'd also note the (3) bullets above the one you mentioned. Those seem to give you some chances to combine series ratings, or use a 3rd fully rated breaker anywhere in the combination.
But to be honest, my head is spinning after reading those bullets.
They do list table 13 which includes triple ratings - but that looks like a pretty short table.
I'd also note the (3) bullets above the one you mentioned. Those seem to give you some chances to combine series ratings, or use a 3rd fully rated breaker anywhere in the combination.
But to be honest, my head is spinning after reading those bullets.
electrofelon
Senior Member
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- Cherry Valley NY, Seattle, WA
Yes it is a bit confusing and requires some cogitating. That Eaton manual seems to have the best instructions for applying series ratings that I have found. The ones form other manufacturers seem to just list the series ratings without describing how to use them and apply to things like combinations.
Just to be very specific, this is the kind of thing that people seem to incorrectly do all the time, and I admit I thought was ok in the past:
Devices A,B, C from utility to branch. Say actual AFC is 65k. Say AFC at C is not significantly lower to allow its use without a series rating. AIC of A is 65k, B is 22K, C is 10k (full, not series ratings). Say a series rating exists for A and B, and also for B and C. Many will apply both to use these three devices together. The problem is, the AFC at B is not actually 22k so you cant use the B-C series rating. The only way to use these three together is if they have a tested three tier rating.
Square D seems to have a decent number of three tier ratings, Eaton as a few, but if I am reading that correctly, the first device has to be a fuse in all cases. Siemens I cant find any.
Just to be very specific, this is the kind of thing that people seem to incorrectly do all the time, and I admit I thought was ok in the past:
Devices A,B, C from utility to branch. Say actual AFC is 65k. Say AFC at C is not significantly lower to allow its use without a series rating. AIC of A is 65k, B is 22K, C is 10k (full, not series ratings). Say a series rating exists for A and B, and also for B and C. Many will apply both to use these three devices together. The problem is, the AFC at B is not actually 22k so you cant use the B-C series rating. The only way to use these three together is if they have a tested three tier rating.
Square D seems to have a decent number of three tier ratings, Eaton as a few, but if I am reading that correctly, the first device has to be a fuse in all cases. Siemens I cant find any.
That makes sense.
Now I realize that table 13 only has fuses in the first column. Making 2 of the breakers fully rated is the only option I see.
Now I realize that table 13 only has fuses in the first column. Making 2 of the breakers fully rated is the only option I see.
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