15a+15a = 30a?

So can I build a single 30A heatstick (4500w) using two plugs going to two separate 15A breakers?

Or I could do two 15A heatsticks, just trying to simplify...

rasherb said:

So can I build a single 30A heatstick (4500w) using two plugs going to two separate 15A breakers?

Or I could do two 15A heatsticks, just trying to simplify...

Click to expand...

You have to use 2 heating elements at 15A each, as long as they are plugged into separate breakers. You could physically attach them to the same "handle" for lack of a better word, but they must be electrically isolated.

Never parallel breakers/circuits to one common load!

That'd be no x 3.

First, I don't know where you took your 30A from. A 4500W element consumes 37.5A at 120V, or 18.75A at 240V.

Second, like it's been said before, it's not a good idea to parallel breakers. If you're lucky enough that the breakers are on the same phase, you will most likely have Eddy currents between them, and if they're on different phases, you got pretty much the perfect recipe for an instant fire.

Third, you can't (or, at least, shouldn't) put a 15A load on a 15A breaker. You need a safety margin. Depending on the safety margin you choose to use, you're gonna need, minimum, a 20A breaker (for the "80% rule" commonly used in the US) or a 25A one (for the 70.7%, DIN rule).

Eddy currents? uhhh....no.
Current imbalance? yes.

Bjornbrewer said:

Eddy currents? uhhh....no.
Current imbalance? yes.

Click to expand...

No such thing as a current imbalance.
I wouldn't be surprised if "eddy current" is not the right term, as English is not my native language. What I meant is "spurious currents, due to a voltage imbalance".

Inodoro_Pereyra said:

as English is not my native language.

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For all the electrical debates you find yourself in, I think I would take an English lesson or two.


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wildwest450 said:

For all the electrical debates you find yourself in, I think I would take an English lesson or two.


_

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I probably should. Not an English lesson, but an electronics certification. But, as of now, I have 3 problems: money, time, and age.
Who knows? maybe in the future...

Inodoro_Pereyra said:

Third, you can't (or, at least, shouldn't) put a 15A load on a 15A breaker. You need a safety margin. Depending on the safety margin you choose to use, you're gonna need, minimum, a 20A breaker (for the "80% rule" commonly used in the US) or a 25A one (for the 70.7%, DIN rule).

Click to expand...

The "80% rule" is for design consideration at construction. It does not apply to the consumer. A 15A circuit is expected to carry a 15A load from the consumer's perspective. I don't know too many consumers that run around with ammeters to make sure they aren't exceeding 80% on any branch.

jkarp said:

The "80% rule" is for design consideration at construction. It does not apply to the consumer. A 15A circuit is expected to carry a 15A load from the consumer's perspective. I don't know too many consumers that run around with ammeters to make sure they aren't exceeding 80% on any branch.

Click to expand...

You're right, but you didn't pay attention to the OP's questions.
He didn't ask if he could put a 15A load on a 15A "circuit". He asked if he could put it on a 15A "breaker".
A 15A circuit must be designed with a 20A breaker. If he has a 15A breaker, the circuit is 10A, or 12A by the "80% rule".

jkarp said:

The "80% rule" is for design consideration at construction. It does not apply to the consumer. A 15A circuit is expected to carry a 15A load from the consumer's perspective. I don't know too many consumers that run around with ammeters to make sure they aren't exceeding 80% on any branch.

Click to expand...

Yes and no. If you put 15A on a 15A breaker, it will trip in 3 hours if it is in an enclosure (which obviously is pretty much all the time). The maximum continuous current a breaker is expected to deliver without tripping is 80% of it's rating. There are breakers that are designed to deliver 100% without tripping but they are special, not standard.

Inodoro_Pereyra said:

No such thing as a current imbalance.
I wouldn't be surprised if "eddy current" is not the right term, as English is not my native language. What I meant is "spurious currents, due to a voltage imbalance".

Click to expand...

If you parallel two feeds of different length (hence, different impedances) the one with lower impedence will carry more of the current demanded by the load......hence, current imbalance. Think of two branches in parallel with different resistences, they have differenet currents. Taking into consideration, connections, circuit lengths (though a house), etc, etc. they current imbalance can be such that even though the load is not drawing more than the two feeders can supply (30A = 15A + 15A), one feeder may be overloaded (30A = 12A + 18A).

Bjornbrewer said:

If you parallel two feeds of different length (hence, different impedances) the one with lower impedence will carry more of the current demanded by the load......hence, current imbalance. Think of two branches in parallel with different resistences, they have differenet currents. Taking into consideration, connections, circuit lengths (though a house), etc, etc. they current imbalance can be such that even though the load is not drawing more than the two feeders can supply (30A = 15A + 15A), one feeder may be overloaded (30A = 12A + 18A).

Click to expand...

Yeah, got you now.
I don't know WTH I was thinking, reasoning there would be a spurious current between 2 points at the same potential. Looks like I'm getting rusty...

Inodoro_Pereyra said:

You're right, but you didn't pay attention to the OP's questions.
He didn't ask if he could put a 15A load on a 15A "circuit". He asked if he could put it on a 15A "breaker".
A 15A circuit must be designed with a 20A breaker. If he has a 15A breaker, the circuit is 10A, or 12A by the "80% rule".

Click to expand...

The OP did not give enough information for you to make that determination. Additionally, the 80% rule does not apply to non-continuous loads. Because nobody does a 3 hour boil, brewing is a non-continuous load.

jkarp said:

The OP did not give enough information for you to make that determination. Additionally, the 80% rule does not apply to non-continuous loads. Because nobody does a 3 hour boil, brewing is a non-continuous load.

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Try it.
I can guarantee you the breaker will trip in less than 20 minutes.

Try what? OP said 15A heat stick, which doesn't readily exist. I've never seen 1800W 120V elements, anyway. Closest with easy consumer access is 1650W. If he builds two of those and runs them on separate circuits with no other draws, he'll be a happy brewer. No trips.

Sorry, I forgot this:

jkarp said:

The OP did not give enough information for you to make that determination.

Click to expand...

What part of:

rasherb said:

So can I build a single 30A heatstick (4500w) using two plugs going to two separate 15A breakers?

Or I could do two 15A heatsticks, just trying to simplify...

Click to expand...

Do you find insufficient?

What part of:

rasherb said:

So can I build a single 30A heatstick (4500w) using two plugs going to two separate 15A breakers?

Or I could do two 15A heatsticks, just trying to simplify...

Click to expand...

Was already clearly defined as a BAD and UNSAFE idea in this thread?

Your troll is weak.

jkarp said:

Try what? OP said 15A heat stick, which doesn't readily exist. I've never seen 1800W 120V elements, anyway. Closest with easy consumer access is 1650W. If he builds two of those and runs them on separate circuits with no other draws, he'll be a happy brewer. No trips.

Click to expand...

Not the point. Now you're just trying to twist everything, just to "win" an argument.
The OP talked about a 15A heat stick. For all we know, he may have made, or be planning to make, a 15A heatstick. You don't know if he's planning to use 1, 2 or more heating elements in a single heatstick.
But even if he used a 1650W HE, that'd still put him at 91% of the breaker's rated current. whether you like it or not, IT'S UNSAFE. Period.

jkarp said:

What part of:

Originally Posted by rasherb
So can I build a single 30A heatstick (4500w) using two plugs going to two separate 15A breakers?

Or I could do two 15A heatsticks, just trying to simplify...

Click to expand...

Was already clearly defined as a BAD and UNSAFE idea in this thread?

Your troll is weak.

Click to expand...

So you think what you quoted is NOT UNSAFE?

And you're calling ME a troll?

Running 15amps on a 15amp breaker is safe... period.

2 things to concider. first, A breaker is there to protect the wires and the plug. Not the load plugged into it. And B, as mentioned, the 80% rule is in the design phase. That means the wire in the wall to the receptical is rated at 80% max. So the 14ga wire and receptical in a 15amp circuit will not burn up with 20amps.

rasherb said:

So can I build a single 30A heatstick (4500w) using two plugs going to two separate 15A breakers?

Or I could do two 15A heatsticks, just trying to simplify...

Click to expand...

I have to completely agree with bjornbrewer, Charlie in TX, and jkarp (even though he brews sucky beer).

I suggest making two heatsticks... with each heatstick using a 1500W or 1650W, whichever you can find for cheaper, and with each heatstick using it's own dedicated 15A breaker. However, always make sure you plug the heatstick into a GFCI outlet. That way you'll make sure to stay a happy brewer.

I currently use a heatstick with a 2000W element and with it's own 20A breaker, and it's always plugged into a GFCI outlet.

Hey sorry I've been absent here. I have this huge box of 9v batteries I've been working through licking each one to see if it still holds a charge.
I essentially was trying to make a 30 amp outlet out of 2 15 amp breakered outlets.
sounds like that won't work because of the whole impedance imbalance thing.
thanks for the help! ...back to the box of batteries

rasherb said:

Hey sorry I've been absent here. I have this huge box of 9v batteries I've been working through licking each one to see if it still holds a charge.
I essentially was trying to make a 30 amp outlet out of 2 15 amp breakered outlets.
sounds like that won't work because of the whole impedance imbalance thing.
thanks for the help! ...back to the box of batteries

Click to expand...

Buy a multimeter. Much easier. Save your tongue for the windows