thargrav
Well-Known Member
A while ago I started a thread about installing a electric water heater element into a stainless steel brew pot. I got chastised about using a 14 gauge power cord to carry what could easily be 17 amps and several quoted that 14 gauge should carry a maximum of 15 amps.
I finally took the time today to chase down the answer about #14 wire and current carrying capacity. And I am correct - #14 wire is perfectly safe for up to 20 amps! But don't believe me, do your own research starting with table 310.16 in the NEC code book.
It is true that #14 wire is used to carry up to 15 amps in house & commercial wiring and #12 wire is used to carry up to 20 amps, and some believe that this means you can only use #14 wire for up to 15 amps. And everywhere you look on the net you see "experts" claiming that #14 wire is only good for up to 15 amps. But it turns out that all of these "experts" are only quoting partial facts, or maybe they are quoting the local "expert" at LOWE'S? Is this is another example of "if it's on the net it must be true"? I don't know but it sure seems so.
But here is the real deal. The same NEC code that specifies that #14 wire can carry no more than 15 amps states that #14 in a branch circuit is good for up to 20 amps (table 310.16 in NEC clearly states the max of 20 amps)! A branch circuit is a circuit run to a single device and this sure reads like a power cord to me, but not a extension cord. In other words, #14 gauge is perfectly safe for 20 amps, they just don't want you to run a string of 20 Amp outlets across your house with #14 wire. And they are correct with this - they are concened about voltage drop across distances.
I dug further into my Engineering books and discovered that #14 wire is actually good for up to 32 amps in chassis wiring.
Also, don't use this info as an excuse to run sub-standard or under size wiring in any of your projects. You still need to brew safe!
I finally took the time today to chase down the answer about #14 wire and current carrying capacity. And I am correct - #14 wire is perfectly safe for up to 20 amps! But don't believe me, do your own research starting with table 310.16 in the NEC code book.
It is true that #14 wire is used to carry up to 15 amps in house & commercial wiring and #12 wire is used to carry up to 20 amps, and some believe that this means you can only use #14 wire for up to 15 amps. And everywhere you look on the net you see "experts" claiming that #14 wire is only good for up to 15 amps. But it turns out that all of these "experts" are only quoting partial facts, or maybe they are quoting the local "expert" at LOWE'S? Is this is another example of "if it's on the net it must be true"? I don't know but it sure seems so.
But here is the real deal. The same NEC code that specifies that #14 wire can carry no more than 15 amps states that #14 in a branch circuit is good for up to 20 amps (table 310.16 in NEC clearly states the max of 20 amps)! A branch circuit is a circuit run to a single device and this sure reads like a power cord to me, but not a extension cord. In other words, #14 gauge is perfectly safe for 20 amps, they just don't want you to run a string of 20 Amp outlets across your house with #14 wire. And they are correct with this - they are concened about voltage drop across distances.
I dug further into my Engineering books and discovered that #14 wire is actually good for up to 32 amps in chassis wiring.
Also, don't use this info as an excuse to run sub-standard or under size wiring in any of your projects. You still need to brew safe!