Cold Fusion
Senior Member
- Location
- way north
Philly -
Just to keep from jumping around, my discusson is limited to Non-strange stuff motors and instantaneous trip CB used in listed combination starters.
And, I don't know where this 2.5X FLC comes from. If one were picking an Inverse Time Breaker from T430.52, then 2.5X FLC is where you would start. But we are not.
So the guiding principle for the breaker rating is 43.110. And it says .... (this is a test, you get to fill this in)
Practically: I'd tell AB what the motor hp was, and use their standard bucket configuration. And they might tell me to choose between the energy efficient or not energy effecient.
However, for an example, I'll pick 230V, 1.5hp, 6.0FLC. The rating of the CB has to be at least 1.15X or 6.9A. So a 7A rating is fine - a 15A is also fine. Now look at the instantaneous settings. Since I don't know if the motor will be an energy efficient or not, and I get to use the engineering evaluation section of 430.52.C.3, I'll pick the smallest one with settings that can get up to 17X (102A)
cf
Just to keep from jumping around, my discusson is limited to Non-strange stuff motors and instantaneous trip CB used in listed combination starters.
No, I'm refering to the breaker. The breaker is the disconnect. 430.110 is refering to the rating of the disconnect.I'm assuming here, you are referring to the ratings of the contactors and not the breakers correct? ...
The motor FLA doesn't matter. It's the motor FLC, from T430.150.... So as an example lets say I had a motor with a FLA of 7A. If I was going to select a circuit breaker would I start with 2.5* this value and select maybe a 15A breaker. ...
And, I don't know where this 2.5X FLC comes from. If one were picking an Inverse Time Breaker from T430.52, then 2.5X FLC is where you would start. But we are not.
So the guiding principle for the breaker rating is 43.110. And it says .... (this is a test, you get to fill this in)
Technically: 7A doesn't ever show up in T430.150, so I don't know... Could you technically select a 7A breaker which would be adjustable between 21A and 70A thus allowing you to get to 800%. Or should you use a breaker that allows you to get to 1300% at least?
Practically: I'd tell AB what the motor hp was, and use their standard bucket configuration. And they might tell me to choose between the energy efficient or not energy effecient.
However, for an example, I'll pick 230V, 1.5hp, 6.0FLC. The rating of the CB has to be at least 1.15X or 6.9A. So a 7A rating is fine - a 15A is also fine. Now look at the instantaneous settings. Since I don't know if the motor will be an energy efficient or not, and I get to use the engineering evaluation section of 430.52.C.3, I'll pick the smallest one with settings that can get up to 17X (102A)
cf