Simple question, wires in parallel. How much current gain? If any?
Simple question, wires in parallel. How much current gain? If any?
(OP)
In theory, and in practice.
I am running 110 AC current through some number 12 wire. Number twelve is not adequate.
I can easily double up on the wires. Run two number 12 wires in parallel. Same gauge, same length.
Question, what does this gain me?
Does this double my load carrying capacity? Or no?
How does the math work?
Jon
I am running 110 AC current through some number 12 wire. Number twelve is not adequate.
I can easily double up on the wires. Run two number 12 wires in parallel. Same gauge, same length.
Question, what does this gain me?
Does this double my load carrying capacity? Or no?
How does the math work?
Jon






RE: Simple question, wires in parallel. How much current gain? If any?
Number 12 wire, as used in houses and such, can safely carry 20 amperes at 110 volts AC. Number 12 wire can also 20 amperes at 12 to 14 volts DC, as in a car.
But the same wire is not suitable for both. House wire is normally solid, i.e. a single conductor. It bends, and stays bent.
Car wire is normally stranded, i.e., made of 7 or 19 or more smaller conductors, all twisted together, because it's more flexible, and resistant to vibration.
All of that is tangential, really. After you read up a little on basic electricity, your next step is to find out what your actual load is, by measuring (or looking up) the current required in amperes, or the power required in watts.
Back to not actually answering your questions...
How do you know that "Number twelve is not adequate."? Is the load not working right? Is the wire getting hot?
Mike Halloran
Pembroke Pines, FL, USA
RE: Simple question, wires in parallel. How much current gain? If any?
Wire is getting warmer than I like. Not hot, but warm enough to worry me.
Just not sure if doubling the wire doubles the capacity. As I would think, at face value.
Is there any black magic at work here?
RE: Simple question, wires in parallel. How much current gain? If any?
A general answer is that you can double the current carrying capacitiy by doubling the number of wires. Depending on code (NEC, EU etcetera) you have to consider different fusing arrangements. So you cannot just double the number of wires. There's usually more to it.
But, as Mike says, is it the voltage or the current that is a problem? You cannot get an answer without telling us what the problem is.
Gunnar Englund
www.gke.org
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Half full - Half empty? I don't mind. It's what in it that counts.
RE: Simple question, wires in parallel. How much current gain? If any?
Hire an expert.
Bill
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"Why not the best?"
Jimmy Carter
RE: Simple question, wires in parallel. How much current gain? If any?
The fan runs okay, just worried about the wire running a bit warm.
Not too concerned with the codes here in Moose Snort, just trying to understand the theory.
If doubling the wire does indeed double the capacity, I have my answer.
What say the gallery?
Thanks,
Jon
RE: Simple question, wires in parallel. How much current gain? If any?
In the NEC applies, you have to just use a larger wire size until you get to 2/0 or beyond. Then you can begin to parallel wires.
RE: Simple question, wires in parallel. How much current gain? If any?
Warm is what I am dealing with. Not more than 120f or so.
I do not wish to get much past ambient.
Does anyone understand the math? What (if anything) do I gain by doubling up and running parallel?
Is there any "path of least resistance" to factor in? Or similar principals?
Jon
RE: Simple question, wires in parallel. How much current gain? If any?
In this particular case, the math even has a name: Ohm's Law.
Then, there's another piece of math named Thevenin's theorem.
Want more math? What about Kirchoff's laws?
Look them up on the net and apply them. Or, you could talk to your 'principals'
Gunnar Englund
www.gke.org
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Half full - Half empty? I don't mind. It's what in it that counts.
RE: Simple question, wires in parallel. How much current gain? If any?
With the fan ON you or your electrician should measure the voltage at the FAN. If it's less than about 108VAC the motor is suffering.
Since it's against the regs we work by around here we're not going to tell you to parallel some #12s up.
Keith Cress
kcress - http://www.flaminsystems.com
RE: Simple question, wires in parallel. How much current gain? If any?
RE: Simple question, wires in parallel. How much current gain? If any?
Ampacity is determined by how much current will cause the conductor to heat (by I²R losses) to the limiting temperature of the insulation. Mutual heating of the wires will reduce the ampacity.