You are using an out of date browser. It may not display this or other websites correctly.
You should upgrade or use an alternative browser.
You should upgrade or use an alternative browser.
Wire and breaker sizing
- Thread starter hochwire
- Start date
- Status
- Not open for further replies.
inspector 102
Senior Member
- Location
- Northern Indiana
Re: Wire and breaker sizing
I think Article 240.4 of the NEC addresses this issue for the overcurrent device protecting the branch circuit serving this vacuum. I believe there are provision for the internal wiring to be reduced based on temp. rating but not the OCP.
I think Article 240.4 of the NEC addresses this issue for the overcurrent device protecting the branch circuit serving this vacuum. I believe there are provision for the internal wiring to be reduced based on temp. rating but not the OCP.
bonding jumper
Senior Member
Re: Wire and breaker sizing
I have a feeling this vaccum is to be hardwired not chord and plug? Hardwired, would permit use of a 30A circuit breaker with #10 wire. But if its chord and plug, and the plug is a standard 120v 20a configuration, you have to use 20A circuit breaker. You are not allowed by code to protect a 20a chord with a higher rated circuit breaker.
I have a feeling this vaccum is to be hardwired not chord and plug? Hardwired, would permit use of a 30A circuit breaker with #10 wire. But if its chord and plug, and the plug is a standard 120v 20a configuration, you have to use 20A circuit breaker. You are not allowed by code to protect a 20a chord with a higher rated circuit breaker.
bonding jumper
Senior Member
Re: Wire and breaker sizing
Then I would go with the 30A #10 wire configuration. I would imagine the car wash vacume would be working hard and almost constant, if not, its still a motor load so I would increase the nameplate rating to 125% above, or 25A and protect it with a 30A just incase the thing gets clogged, is working hard and draws a little extra power to prevent neuance tripping.
Then I would go with the 30A #10 wire configuration. I would imagine the car wash vacume would be working hard and almost constant, if not, its still a motor load so I would increase the nameplate rating to 125% above, or 25A and protect it with a 30A just incase the thing gets clogged, is working hard and draws a little extra power to prevent neuance tripping.
bphgravity
Senior Member
- Location
- Florida
Re: Wire and breaker sizing
I would first determine the FLC rating from Table 430.148 using the nameplate horsepower rating of the motor. I would then increase FLC by 125%. The ground-fault and short-circuit device could be sized at 250% of the FLC.
(See 430.6, 430.22, 430.52)
I would first determine the FLC rating from Table 430.148 using the nameplate horsepower rating of the motor. I would then increase FLC by 125%. The ground-fault and short-circuit device could be sized at 250% of the FLC.
(See 430.6, 430.22, 430.52)
allenwayne
Senior Member
Re: Wire and breaker sizing
Does the data plate have a max breaker size listed ?
Does the data plate have a max breaker size listed ?
- Status
- Not open for further replies.