circuit breaker sizing

[gniehues]

one of the questions on a code test stated. What size circuit breaker is required if you have 3 current carrying conductors in a 5 foot piece of 1inch PVC conduit. Any suggestionson how to figure this?

 

[bphgravity]

Re: circuit breaker sizing

The question does not provide enough information.

 

[charlie b]

Re: circuit breaker sizing

As a minimum, you would need to know the current drawn by the load and the type of load (i.e., motors, transformers, and lights have different rules). There could also be a trick to the question, if for example the conductors were too large to fit into that size and type of conduit. What kind of test was this?

 

[tshea]

Re: circuit breaker sizing

For grins & giggles--was there any options, like a multiple guess test? Or was this an open answer test?
My choice would be "I dunno"

Definately not enough info.

 

[physis]

Re: circuit breaker sizing

I've never seen the "I dunno" choise.

 

[George Stolz]

Re: circuit breaker sizing

42.

 

[pierre]

Re: circuit breaker sizing

3-pole

[ March 15, 2005, 10:05 PM: Message edited by: pierre ]

 

[George Stolz]

Re: circuit breaker sizing

Oh, I thought the question was "the secret of life, the universe, and everything."

No Hitchhiker's fans here?

 

[hurk27]

Re: circuit breaker sizing

By tshea: Or was this an open answer test?

Is that the test they give those DYS's that they feel sory for? :roll:

 

[charlie b]

Re: circuit breaker sizing

Originally posted by georgestolz: Oh, I thought the question was "the secret of life, the universe, and everything."

No Hitchhiker's fans here?

We're too busy trying to find out what happened to the dolphins.

 

[hurk27]

Re: circuit breaker sizing

They swam out to sea.

 

[tshea]

Re: circuit breaker sizing

6 X 7

 

[celtic]

Re: circuit breaker sizing

ummm, sorry...we were looking for "miter saw".
Miter saw.

 

[charlie b]

Re: circuit breaker sizing

Originally posted by tshea: 6 X 7

No. The question was eventually determined to be "What do you get when you multiply nine by seven?" And if anyone tries to use a calculator to prove that this does not work out to "42," then I would say that you do not understand the question. For more information, do a google search for Douglas Adams.

 

[kturner]

Re: circuit breaker sizing

The size of a 3 pole breaker would be 3 inches.

 

[bigjohn67]

Re: circuit breaker sizing

Sure the question was not " what is allowed"
The 5ft of conduit will result in no derating.

So look at the chart and see what is the largest conductor allowed to be in 1' conduit in the amount of 3. Then look at the code for the max over current protection with no derating.
So many people over think these questions.

Atleast if you get it wrong you can argue your point with them.

[ March 22, 2005, 09:59 PM: Message edited by: bigjohn67 ]

 

[hurk27]

Re: circuit breaker sizing

6x9=42 base 13