Wiring 15kw heat stips

[William1978]

im sure that it won't run for 3 hours or more, but who knows...im sure im supposed to consider this a continuous load

Doesn't the name plate already have 125% figured in?

 

[Buck Parrish]

yes, this unit has a 30 and a 60 on it already...it has a bonding strap if you choose to run one feeder or you can remove it to use two wires

Then it is fine.
Because the controll wiring must be wired to both strips.
So when the sensors click off. One strip and or the other will go off.

 

[NolaTigaBait]

Doesn't the name plate already have 125% figured in?

im sure it does....it has a 60 and a 30 amp breaker in it...i guess they are telling you all you need to know right there...i was just curious how others would choose to wire this heater

 

[Jim W in Tampa]

Doesn't the name plate already have 125% figured in?

No 10 kw is just that ,not 8 kw.Exspect full 10 kw

 

[augie47]

There is nothing wrong with this instalation. You can put #6 romex on a 60a and #10 on a 30a breaker all day long. I would do it this way if I already had the wire.

put #6 Romex on a 60 amp breaker with a load over 55 amps and you will get a red tag in this area.

 

[Jim W in Tampa]

put #6 romex on a 60 amp breaker with a load over 55 amps and you will get a red tag in this area.

why ?????????????????

 

[C3PO]

put #6 Romex on a 60 amp breaker with a load over 55 amps and you will get a red tag in this area.

And it should get a red tag :smile:

 

[augie47]

because of it's 55 amp ampacity

 

[William1978]

put #6 Romex on a 60 amp breaker with a load over 55 amps and you will get a red tag in this area.

And it should get a red tag :smile:

Why should this fail??????????????

 

[William1978]

because of it's 55 amp ampacity

They don't make a 55a breaker check 240.6

 

[William1978]

because of it's 55 amp ampacity

You can go to the next standard size.

 

[Jim W in Tampa]

Got a code number ? Or this just what the boys want there ?

 

[roger]

They don't make a 55a breaker check 240.6

Read Augie's post again in it's entirety.

Roger

 

[C3PO]

You can go to the next standard size.

Got a code number ? Or this just what the boys want there ?

You can not use 240.4 to bump up to a 60A breaker if the calculated load exceeds the 55A that the wire is good for. This comment is from NEC Plus website commentary to 240.4:

" For circuits rated 600 volts and under, the allowable ampacity of branch circuit, feeder, or service conductors always has to be capable of supplying the calculated load in accordance with the requirements of 210.19(A)(1), 215.2(A)(1), and 230.42(A).

 

[NolaTigaBait]

it says you CAN go up to the next size breaker ..

 

[NolaTigaBait]

You can not use 240.4 to bump up to a 60A breaker if the calculated load exceeds the 55A that the wire is good for. This comment is from NEC Plus website commentary to 240.4:

" For circuits rated 600 volts and under, the allowable ampacity of branch circuit, feeder, or service conductors always has to be capable of supplying the calculated load in accordance with the requirements of 210.19(A)(1), 215.2(A)(1), and 230.42(A).

well, its a 10 kw load, so i dont htink theres a problem

 

[William1978]

Read Augie's post again in it's entirety.

Roger

We are talking about 10KW heat strips right? and not any other loads.

 

[NolaTigaBait]

We are talking about 10KW heat strips right? and not any other loads.

right, and a little more for the motor...but still

 

[Jim W in Tampa]

#6 thhn is good for what at 75 degrees ????????????? i best buy a new book.

 

[augie47]

They don't make a 55a breaker check 240.6

true, but 310 lsits the ampaciy of the conductor.
240.6 allows you to go to the next standard OCP device, but does not permit you to exceed the conductor's ampacity.