- Location
- Lockport, IL
- Occupation
- Retired Electrical Engineer
What does that mean? It?s a matter of some debate in my office. Here is an example:
Question 1: Since the connected load exceeds 80% of the 225 amp main breaker rating, would I need to call for a 100% rated breaker?
Question 2 (assumes the answer to Question 1 is ?no?): Since the demand load exceeds 80% of the 225 amp main breaker rating, would I need to call for a 100% rated breaker?
Question 3: Does the notion of ?80% rated breaker? mean,
- A dwelling unit has a main service panel rated for 225 amps.
- It has a main breaker rated for 225 amps, but it is an 80% rated breaker.
- 80% of 225 is 180 amps.
- Suppose the total connected load is 200 amps. But after applying the appropriate demand factors (e.g., 125% for continuous loads, 35% for lighting over 3KVA, 80% for 4 kitchen appliances, or whatever else might apply), the ?demand load? is 185 amps.
Question 1: Since the connected load exceeds 80% of the 225 amp main breaker rating, would I need to call for a 100% rated breaker?
Question 2 (assumes the answer to Question 1 is ?no?): Since the demand load exceeds 80% of the 225 amp main breaker rating, would I need to call for a 100% rated breaker?
Question 3: Does the notion of ?80% rated breaker? mean,
- The total connected load cannot exceed 80% of the breaker?s current rating,
- or
- The breaker can handle a load of 80%, all of it being continuous, so that the calculated load works out to be the same as the breaker?s current rating,
- or
- The breaker can handle a load of 100% of its current rating, as long as none of the load is continuous,
- or
- Both B and C above,
- or
- None of the above?