12gauge extension cord rated at only 15Amps

I have a 12gauge extension cord that I currently use for my 2000w/20A heat stick. I have noticed in the past the these extension cords are only rated for 15 amps regardless of the 12 gauge wires. Is this because the plug is not rated for 20A? Other than this I can't see why it would not be rated for 20Amps. Is there some other difference between this and a regular 12/3 cord? I have never felt the cord get hot after extended use.

The cord probably does not have a 20 Amp receptacle on it.

How long is the cord?

Sawdustguy said:

The cord probably does not have a 20 Amp receptacle on it.

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Gremlyn1 said:

How long is the cord?

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It does not but I'm planning to cut it in half to use to supply my HLT element. It is currently 25' or 50' long and I will be cutting in half to share with both my heatstick and HLT. When I cut it I will be putting on a 20A rated plug.

Length matters (that's what she said) but I'd only de-rate it to 15amps if it was left as 50 feet or more. There's no problem running 20amps over a 25 foot length of 12/3 SJ.

Bobby_M said:

Length matters (that's what she said) but I'd only de-rate it to 15amps if it was left as 50 feet or more. There's no problem running 20amps over a 25 foot length of 12/3 SJ.

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Exactly what I was driving at.

12 gauge is fine for 20 amps - It's the standard plug and receptacle that are rated for 15.

If it bothers you, you can cut them off and use proper 20 amp fittings.

Even the short 12 gauge extension cords were only rated for 15amps. I figured the limiting factor was the plug. If they throw a 20amp plug on there it would limit the outlets you could use it on. Just wanted to be certain I wasn't missing something in regards to the rating for the actual wire.

Length can be a factor since resistance goes up. I think it does have to do with it having 20amp ends on it.

So I stopped at HD again tonight. Both the Husky brand and Rigid brand 12gauge extension cords are rated for 15A only. In my eyes 12 gauge wire is 12 gauge wire. BUT the 15amp ends, as already mentioned, would limit the rating of the plug. I can't see how this would make much difference for our uses. I'm not worried about the rating of the plug so much as the wire. Luckily if the house catches fire I can run out the brewing garage rather quickly.

Scut_Monkey said:

So I stopped at HD again tonight. Both the Husky brand and Rigid brand 12gauge extension cords are rated for 15A only. In my eyes 12 gauge wire is 12 gauge wire. BUT the 15amp ends, as already mentioned, would limit the rating of the plug. I can't see how this would make much difference for our uses. I'm not worried about the rating of the plug so much as the wire. Luckily if the house catches fire I can run out the brewing garage rather quickly.

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I think that the possibility of a consumer using the cord all coiled up contributes to the manufacturer lowering the limit. A long extension cord coiled up will become quite warm after a while, especially if you are drawing 15A through it.

Quaffer said:

I think that the possibility of a consumer using the cord all coiled up contributes to the manufacturer lowering the limit. A long extension cord coiled up will become quite warm after a while, especially if you are drawing 15A through it.

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I see your point. I have run my heat stick at 2000W (16.6amps) for 1-2 hours at a time and I have never felt anything above room temperature on the cord. Granted it's laying on a concrete garage floor. Perhaps it's just labeled for 15amp usage with the 15amp ends installed to give a bigger safety margin.

The thing that is irritating is why even sell a 12 gauge extension cord if both the 12 gauge and 14 gauge versions are rated for 15amps. I think it's safe and I'm very cautious when dealing with electricity and gas.

Yeah, my 12ga cords are only rated 15A.

I do the "Touch Test". When the sticks have been running a while, I touch all the (insulated) connections to see how warm they are getting.

Even back in the summer, when it was HOT, they never got more than "really warm".

Sooner or later, I will be going to 220v elements with PID/Brewtroller/SSR control, but the 20A 120V stuff works fine for now.

Cpt_Kirks said:

Yeah, my 12ga cords are only rated 15A.

I do the "Touch Test". When the sticks have been running a while, I touch all the (insulated) connections to see how warm they are getting.

Even back in the summer, when it was HOT, they never got more than "really warm".

Sooner or later, I will be going to 220v elements with PID/Brewtroller/SSR control, but the 20A 120V stuff works fine for now.

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When you consider that 12 AWG stranded has a resistance of: 1.65 Ohms / 1000 feet (606.06 feet per Ohm) and you are drawing the full load of 15 amps the power dissipated by the cord is (P=I^2R) 18.56 watts=15^2 x .0825. I would say that 18 watts is a considerable amount of power to be dissapated by the cable. I would shorten up the cable.

Reviving an old thread...
If the 12/3 extension cords are rated for 15 amps due to the plugs. Does this mean if I plug the male end into a 20 amp receptacle it will only draw 15 amps? Will I have to replace the male end with a 20 amp plug?
(I'm putting a female 20 amp iec connection on the female side)

Twang, The plugs (or outlets) do not limit the amount of current. The breaker (or over current device) limits the amount of current. You can run more than 15 amps through a 15 amp outlet, but not for too long... 15 amps is the max the device will safely handle according to industry standards.

Just to clear some things up ... There are several factors that determine the rating on a cord. Yes the physical plug is a determination as far as what it is rated for. Edisons style are typically 15A though can be found with 20A ratings. What additionally comes into the mix is how the actual cable is constructed. You will notice that a single 18ga wire in free air is rated for 14 amps - much smaller then 12ga commented on in previous posts. The determining factor is the insulation and the ability of the conductor to dissipate heat under load - this is of special concern with multi-conductor cables. Remember your "standard" orange extension cord is rated to deal with ambient temperatures from freezing to well over 100 deg. Hope this helps clear some things up.

So if I am buying a replacement male plug to put on an extension cord I have cut, does it have to say it's rated for 20amps? Or will a 15 amp male plug still draw 20 amps fine from a 20 amp receptacle?

Could I use something like this to connect my 2000w 120v heating element to my 20amp receptacle?

To start I am no electrical guru and this is just MY experience. From what I noticed the 15amp/12 gauge extension cord I had worked ok for my 2000watt heat stick when plugged into a 20 amp gfci outlet wired to a 20amp breaker.

However, there was nothing scientific about reaching this conclusion except the fact that I didn't start a fire. I have used the heatstick a total of about 12 times and I find the concept of heatsticks to be less safe than the idea of using a 12 gauge/15 amp extension cord to power it. Although less flexible for our needs, the safer setup is to mount the element within the brewpot.

Just my novice opinion.

Twang said:

Could I use something like this to connect my 2000w 120v heating element to my 20amp receptacle?

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In my experience, that will work. I believe others use that syle as well. Using a 20 amp plug would be compliant and have advantages. Boiling ten gallons is inherently dangerous using gas or electric.

wilserbrewer said:

In my experience, that will work. I believe others use that syle as well. Using a 20 amp plug would be compliant and have advantages. Boiling ten gallons is inherently dangerous using gas or electric.

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I would say that it should NOT be used. The specs say it's a 15A/125V plug, not 20A.

As someone mentioned above, the plugs or wires do not "draw" current. They carry the current. How much current is drawn is set by the device connected to the end, in this case a 2000W element. The 2000W element will draw 2000 watts. You need to use plugs/wires/etc that allow for 2000W, including making sure the amps and voltages used are allowed.

Technically speaking circuit breaker in the wall does NOT limit the current through the wire. The circuit breaker will simply cut the power if the current gets too high in order to protect the wire.

You need to use wire rated to 20 amps / 125V. You need to use plugs and receptacles also rated to 20 amps / 125V. The circuit breaker should be set small enough to protect the wire.

Kal

Twang said:

So if I am buying a replacement male plug to put on an extension cord I have cut, does it have to say it's rated for 20amps? Or will a 15 amp male plug still draw 20 amps fine from a 20 amp receptacle?

Could I use something like this to connect my 2000w 120v heating element to my 20amp receptacle?

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The 12gauge extension cords already come with a 15amp rated plug so I'm not sure why you would replace it with another 15amp rated piece. To replace it with a 20amp plug is what you should consider. Again, I had no problems using a 12gauge extension cord that came with a 15amp plug. However, it is not rated for that use and the only reason I never changed it to a 20amp plug was the fact that I got away from heatsticks all together.

Scut_Monkey said:

The 12gauge extension cords already come with a 15amp rated plug so I'm not sure why you would replace it with another 15amp rated piece. To replace it with a 20amp plug is what you should consider. Again, I had no problems using a 12gauge extension cord that came with a 15amp plug. However, it is not rated for that use and the only reason I never changed it to a 20amp plug was the fact that I got away from heatsticks all together.

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I am cutting it to use for power from 20amp wall receptacle to control panel, and the other piece from the heating element to receptacle in control panel box.

I can't find any 20 amp rewireable plugs with the typical holes for a 15amp outlet.

The receptacle I'm planning on using in the control box to attach the heating element to says "Class A GFCI 20A 2P 125V 60HZ" but also says "Spec Grade ShackSentry 15A Receptacle" on it, any logic to this?

Do I need a new receptacle and rewireable plugs with the one prong/hole that is perpendicular to the other?

I appreciate the help from you guys that are knowledgable on this topic. As you can tell, I am not too electrical savvy but want to do this as simple, safe and proper as possible.

Is it a regular rectangular GFCI? If it is, you can go to Menards and get a 20 amp rated one with the perpendicular prong for about $8.00

I would be skeptical of anything rated for 20 amps when the prongs are parallel. Simply producing them would seem like a code violation.

In the end, straight blades should work fine. The wire is rated for 20 amps, and mechanically, the 15 amp and 20 amp plugs are the same.

OTOH, if your place burns down and the inspector finds that things aren't kosher, it's just one more thing for the insurance company to use against paying out...