JDBrown
Senior Member
- Location
- California
- Occupation
- Electrical Engineer
This is one of those things that I feel like I ought to know, but I don't. I've heard of 80% rated breakers and 100% rated breakers in passing, but I'm not really clear on what those terms mean, or on how common one or the other is in the wild. So, can somebody explain to me what an 80% rated breaker is vs. a 100% rated breaker?
I'm guessing that maybe a 100% rated 30 amp breaker could supply a continuous load of up to 30 amps, while an 80% rated 30 amp breaker could only supply a continuous load of 24 amps (80% of 30 amps) -- but that's only a guess. Can someone please confirm, or explain to me what this really means?
Also, how common are 100% and 80% rated breakers? One of the guys I work with claims that they stopped making 80% rated breakers years ago, and all new breakers are 100% rated. Another guy I work with claims that most breakers are 80% rated, and 100% rated breakers are special-order items that you have to specifically request if you need them. But the reality of the situation is that none of us are actually out in the field, working with and handling breakers on a daily basis--so I seek knowledge from those of you who do.
I'm guessing that maybe a 100% rated 30 amp breaker could supply a continuous load of up to 30 amps, while an 80% rated 30 amp breaker could only supply a continuous load of 24 amps (80% of 30 amps) -- but that's only a guess. Can someone please confirm, or explain to me what this really means?
Also, how common are 100% and 80% rated breakers? One of the guys I work with claims that they stopped making 80% rated breakers years ago, and all new breakers are 100% rated. Another guy I work with claims that most breakers are 80% rated, and 100% rated breakers are special-order items that you have to specifically request if you need them. But the reality of the situation is that none of us are actually out in the field, working with and handling breakers on a daily basis--so I seek knowledge from those of you who do.