Amps vs wattage question

[Zibe]

I have a 20amp breaker powering powering 5 outlets in my garage and I want to put a 2000w element in my kettle. I understand a 20amp breaker will run 2000w but possibly only if it is a dedicated outlet? I can make sure nothing else is plugged in the other outlets with the exception of my garage door opener (I don't have a ladder tall enough to unplug it) but I can ensure it's not used but even when not in use it has the low voltage motion sensors and an led on the control panel (normal garage door stuff) is this possible or a bad idea
Thanks for any help hopefully I can understand any answers.


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[heckels]

The low voltage will not draw anything that would put enough load on that circuit to worry about.

Brew away!


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[passedpawn]

If your garage door has sensors, just put a sock over one of them. The door won't go down.

Worst case, you overload the ckt and the breaker trips. The garage door isn't on long enough to cause the wire insulation to overheat and start on fire. At least that would be my logic.

 

[yogensha]

A 20 amp breaker is only good for 20*0.80 = 16 amps continuous load, which is not quite 2000 watts at 120 volts RMS. IOW, the heating element is likely to trip the breaker by itself anyway.

 

[passedpawn]

A 20 amp breaker is only good for 20*0.80 = 16 amps continuous load, which is not quite 2000 watts at 120 volts RMS. IOW, the heating element is likely to trip the breaker by itself anyway.

I think continuous load is stated to be 3 hours. I can't reference NEC so don't ask

 

[yogensha]

I think continuous load is stated to be 3 hours. I can't reference NEC so don't ask

Yeah, but the 2000W element could exceed the continuous load rating at nominal line voltage anyway. It may work fine forever, it may trip every brew day or something in between. It's too close. In my opinion, at least

 

[Bobby_M]

Disagree. 17amps (most likely less because that current is only if you get 120v which is usually more like 115v) used for a couple hours is not going to trip a 20 amp breaker.

https://www.firearson.com/Publicati...rchive/October-2007-Circuit-Breaker-Myths.pdf

Myth: T-M breakers trip upon reaching the rated current.
T-M breakers trip according to a trip curve, which includes
both 135 percent and 200 percent trip times. At 135 percent
of rated current, the breaker must trip in 1 hour or less.
The trip curve is non linear as loads approach the breaker
ratings (FIGURE 1), therefore, at even 5 percent above trip
rating, there is no guarantee that the breaker will ever trip.

 

[Zibe]

I can keep the garage door opener from turning on I was just saying it does use some voltage just being plugged in for the sensors and light.
From what I've read on another forum a 20 amp breaker can power a 2000w element but it might be at the very limit. And that was on a dedicated outlet. Does the number of outlets on a circuit matter if they aren't being used?
So I guess I'll take it from the top:
1) can a 20 amp circuit power a 2000w element?
2) does it matter if the circuit has four other outlets?
3) does it matter if one of those outlets has a garage door opener plugged in (that will not be used while the element is on) (and if so I'll find a way up there to unplug it some how)
4)most important if it will power the thing do I risk heating up the wires and a fire by running the circuit at its upper limits?
I appreciate all the feedback and I put it in those terms for my stupidity with electricity not yours.


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[Bobby_M]

Yes
No, not if they are not being used.
No
Only if someone wired the circuit with smaller wire that can't handle 20 amps, e.g. 14 gauge wire.

So I guess I'll take it from the top:
1) can a 20 amp circuit power a 2000w element?
2) does it matter if the circuit has four other outlets?
3) does it matter if one of those outlets has a garage door opener plugged in (that will not be used while the element is on) (and if so I'll find a way up there to unplug it some how)
4)most important if it will power the thing do I risk heating up the wires and a fire by running the circuit at its upper limits?



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[The10mmKid]

1) Yes
2) No it doesn't
3) Doesn't matter. I am however surprised the opener is not on its own circuit.
4) I have no concern for the wiring. The weakest link will be any connection from the panel to the outlet with the heatstick.

If it eases your mind, use the outlet that is the GFCI. It is usually (actually required) to be the first of the four outlets.

'da Kid

 

[Zibe]

Thank you
Even I can understand yes and no.
But, are you saying 14 gauge is good for 20a or not enough. The house was built in '06 so I'm assuming it's good but I'll check on the wire gauge.


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[Zibe]

'Da Kid
Thank you,
The GFI outlet is closest to the house so I was betting the others were coming from that one. That is NOT the one I was planning on using I was gonna put a GFI outlet at the one I wanted to use or put in a two gang box on my stand that held a gfi outlet and a switch so I could cut power quick if needed this box would plug into the outlet is that possible or necessary or are all the outlets covered by the first gfi outlet? I have one of those little gfi testers somewhere.


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[orangehero]

20A requires 12 AWG wire and is good for a 2000W heating element and two March/Chugger pumps running simultaneously.

 

[Zibe]

Sounds like you are speaking from experience so I guess if it runs all that I'm good with just the element for sure thanks for the input.


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[Minbari]

'Da Kid
Thank you,
The GFI outlet is closest to the house so I was betting the others were coming from that one. That is NOT the one I was planning on using I was gonna put a GFI outlet at the one I wanted to use or put in a two gang box on my stand that held a gfi outlet and a switch so I could cut power quick if needed this box would plug into the outlet is that possible or necessary or are all the outlets covered by the first gfi outlet? I have one of those little gfi testers somewhere.


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if they are all on the same circuit, then they most likely wired all the outlets through the GFCI. that is why it is the first in the chain.

trip it and see of the other outlets turn off.

 

[The10mmKid]

Each connection between the first GFCI and the other receptacles is an opportunity for failure. Just depends on the electricians wiring skills.
I've been witness to numerous 'meets minimal requirements' wiring methods.


From your description, I would do the following.

1) Go with a heavy duty switch & receptacle on your setup/rig. You will find 20A rated devices at the Big Box stores. Use the style that requires a screw to fasten the wire.
2) Get a heavy duty 20A (12ga) extension cord of the length you need to reach that first GFCI. Cut the outlet end off and permanently wire that to the above setup.

No second GFCI. It adds no value to the project.

That 20A extension cord will only fit a 20A receptacle. That will keep you from cheating on a 15A circuit later.

'da Kid

'Da Kid
Thank you,
The GFI outlet is closest to the house so I was betting the others were coming from that one. That is NOT the one I was planning on using I was gonna put a GFI outlet at the one I wanted to use or put in a two gang box on my stand that held a gfi outlet and a switch so I could cut power quick if needed this box would plug into the outlet is that possible or necessary or are all the outlets covered by the first gfi outlet? I have one of those little gfi testers somewhere.


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[orangehero]

I haven't seen any commonly available 120V extension cords rated to 20A. You can get a 12 AWG extension cord, which is perfectly fine to use at 20A, but they are nominally rated to 15A because they don't use 20A plugs.

 

[GilaMinumBeer]

I haven't seen any commonly available 120V extension cords rated to 20A. You can get a 12 AWG extension cord, which is perfectly fine to use at 20A, but they are nominally rated to 15A because they don't use 20A plugs.

Lowes has a 100ft 20A by Utilitech for $137.00

 

[yogensha]

Disagree. 17amps (most likely less because that current is only if you get 120v which is usually more like 115v) used for a couple hours is not going to trip a 20 amp breaker.

https://www.firearson.com/Publicati...rchive/October-2007-Circuit-Breaker-Myths.pdf

Though quite unlikely, it could higher be than 120 volts.

At 135 percent of rated current, the breaker must trip in 1 hour or less.

This is the upper bound at 25C. The lower bound is on the order of a few minutes[1]. Additionally, the breakers are tested in lab conditions, not inside panels with restricted airflow. Additional heat can be generated by nearby breakers and circuits in the panel as well. As I understand it, this is the genesis of the 80% rule.

I agree I overstated when I said it was "likely to trip." It's probably not likely to trip, but I wouldn't be surprised if it did.

[1] http://www.eaton.com/ecm/idcplg?Idc...As=0&Rendition=Primary&dDocName=1063683065156

 

[Zibe]

Ok thanks again for feedback.
I bought a 20a switch and gfi outlet but tested the outlet I want to use and it switches off when I push the test button and when I use the gfi tester that I have on the gfi outlet that it apparently runs off. I will return the gfi outlet and use a regular 20a one since it appears I am covered by that first gfi outlet.
As for the cord.... I only need a couple feet to connect my brewstand to the wall outlet. I looked at the extension cords and they are pricey is there any issue just using the 12/3 awg type stuff like that is coming off my breakers and putting a plug on it? I know it will be stiffer than an extension cord but any issues other than that?
Once again thanks for the help




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[Zibe]

Yogensha
Lost me a little there but if tripping a breaker is all I have to worry about no biggie that's why I'm looking for the cheapest way to do this it's somewhat of an experiment. If I run the risk of burning my house down that's another story. I've read a few posts on other forums where people are running this type setup. I will let you know how it goes once again thanks for your help



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[Owly055]

A 20 amp breaker will drive your 2000 watt load with no problem. Saying a specific gauge of wire is required to handle 20 amps is nonsense. It's an issue of gauge versus distance. The further you are from the source, the heavier gauge is needed. Too light a gauge wire will have a higher resistance and result in a reduced voltage, which will do nothing more than reduce the output of your heating unit. I hear a lot of "rules of thumb" being bantered around here, but not much real knowledge of electricity and wiring.

In other words........ plug the damn thing and see what happens. If the garage door opens while you are plugged in, nothing terrible will happen...... It will simply trip the breaker. It's not going to burn your house down! Codes are designed to prevent that. The wire will not even get significantly warm before the breaker trips. It is not my intention to insult anybody, but I've worked with this stuff for 40+ years. It's NOT a problem!

H.W.

 

[Zibe]

Sweeeet works for me I've got a few months to get this up and running before winter thanks



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[The10mmKid]

While you can certainly use NM wire (Romex), it's tough to handle and get the connections right on a plug.

I'd like to recommend this wire instead:

Southwire 12-3 Black SJOOW Power Cord

$1.20/ft at Lowes.

'da Kid

Ok thanks again for feedback.
I bought a 20a switch and gfi outlet but tested the outlet I want to use and it switches off when I push the test button and when I use the gfi tester that I have on the gfi outlet that it apparently runs off. I will return the gfi outlet and use a regular 20a one since it appears I am covered by that first gfi outlet.
As for the cord.... I only need a couple feet to connect my brewstand to the wall outlet. I looked at the extension cords and they are pricey is there any issue just using the 12/3 awg type stuff like that is coming off my breakers and putting a plug on it? I know it will be stiffer than an extension cord but any issues other than that?
Once again thanks for the help




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[Zibe]

Once again thank you very much $1.20 a foot sounds perfect I went to menards yesterday to get the other stuff and saw an extension cord like that but it was 50' and way too expensive for the 4-5ft I actually need. I'm assuming it's no problem to cannibalize that for the pigtails (hope that's the right term) inside the box to get the switch hooked up.


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[orangehero]

I get my cords with a 25% coupon at Harbor Freight.

 

[Owly055]

Harbor freight is a good suggestion.

 

[The10mmKid]

Pigtail away.
The flexible wire from the SOOJW cord is way easier to work with.
Make sure you ground the metal box for the switch and receptacle. There will be a place for the ground screw.

Did you know that you can split the receptacle into two sections.
One controlled by the switch and the other always on?
(I'm thinking outside the box, like for a fan or something)

'da Kid

Once again thank you very much $1.20 a foot sounds perfect I went to menards yesterday to get the other stuff and saw an extension cord like that but it was 50' and way too expensive for the 4-5ft I actually need. I'm assuming it's no problem to cannibalize that for the pigtails (hope that's the right term) inside the box to get the switch hooked up.


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[Zibe]

This should be such a simple project but....
I bought the switch and outlet



And then noticed the outlets in my garage (to include the gfi) don't have the horizontal post on the left side which I'm assuming means they are technically 15a outlets but the breaker is 20a at the box and the wire is 12 gauge so this doesn't matter right? the outlet won't fail with 20 amps that other outlet configuration would just be so I don't plug a 20a device in an outlet on a 15a circuit.

Which brings me to another question but I'm assuming I can put a 15a plug on the end of my cord as long as the cord is 12 gauge? I mean a plug and an outlet themselves probably don't have a limit they just denote what the wiring and breaker behind them are rated for?

Please excuse the dumb questions I diy everything at my house but electric is the only thing that makes me nervous.


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[Zibe]

And thanks for the pigtail answer and good tip on harbor freight but while I have Home Depot, lowes, and menards within five minutes I don't even know where the closest one is.


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[The10mmKid]

Well Zibe, you did real good with the switch and outlet.

Yes, it is code to install a 15A receptacle on a 20A circuit.

You SHALL ONLY install the proper angled 20A plug on your setup. No exceptions.

Now let's see how well the electricians or whomever wired the garage did.
I would shut off power to that circuit. Pull that 15A outlet and make sure there is 12ga wired to it. If it is indeed 12ga, replace that outlet with the one you purchased. Of course you'll be buying yet another 20A for your setup.

If it's 14ga(15A) on that 20A breaker, you have way more issues than your project.

Don't fret yet. You're darn near brewing electric!!!

'da Kid

 

[Zibe]

I'm fairly certain the wire is in fact 12 gauge although I'll definitely pull the outlet to check. If I swap out that outlet do I also have to upgrade the gfi behind it or is this just to make sure that at some point in the future I don't plug it into a different 15a outlet.

When I was at menards the 20a plugs all had the vertical post on the right side instead of the left like my outlet. I'm assuming those are 20a 240v plugs? Maybe better luck at lowes when I get the cord.


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[Zibe]

And once again thanks although I'm not sure how close I am haven't even gotten to the element yet and if someday I decide to try to a controller I could tie up this forum for weeks.


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[The10mmKid]

the 15a gfci will be fine. The plug is to force you use a 20a circuit.

lowes has them:
Hubbell 20 amp 125-volt black/white 3-wire grounding plug

are you using an outdoor box and rain cover?

'da kid

i'm fairly certain the wire is in fact 12 gauge although i'll definitely pull the outlet to check. If i swap out that outlet do i also have to upgrade the gfi behind it or is this just to make sure that at some point in the future i don't plug it into a different 15a outlet.

When i was at menards the 20a plugs all had the vertical post on the right side instead of the left like my outlet. I'm assuming those are 20a 240v plugs? Maybe better luck at lowes when i get the cord.

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1

 

[The10mmKid]

Easy peasy:

120v 2000 single element single pump single pid estop
https://www.homebrewtalk.com/f170/list-pj-electrical-diagrams-382286/

and once again thanks although i'm not sure how close i am haven't even gotten to the element yet and if someday i decide to try to a controller i could tie up this forum for weeks.



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1

 

[Zibe]

Alright 'da kid check it out I have acquired:
2-20a outlets (1 for stand 1 for wall)
1-20a switch to cut power
Outdoor boxes and covers for each
Conduit to connect
20a plug
12/3 wire
Wire nuts


It will be attached to this to eventually get rid of that burner forever


I have learned that safety is friggin 'spensive as I could have saved considerable money by cutting some corners (that 20a plug was $10 alone)
Ah well I've got about 2.5 tanks of propane in it so it will pay off eventually.

I went with two separate boxes for the switch and outlet so I could get that fancy exterior switch thingy if I want to cut power don't want to have to open a cover to get to it

Thanks again for your help I found a diagram on how to wire this shouldn't be a problem but I'll post the link when I find it


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[Zibe]

Starting to wire this up starting with the plug

Green wire to "u" prong green screw
Black wire to vertical copper prong
White wire to silver horizontal prong



Feel free to correct me if I go wrong I have no intention of plugging in tonight anyway





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[The10mmKid]

Looks perfect. Nice choice of switch cover. :rockin:

If you go to the plumbing dept, they have a 1/2" grey PVC pipe nipple to connect the two boxes. Or you can use a galvanized nipple.

I used my heat stick just last night. It's amazing how much it contributes to a better brewday. Yep, the propane is still in use too.

I use the stick to shorten 'time to boil', and then let the propane maintain the rolling boil. I don't have a PID YET.


'da Kid

Starting to wire this up starting with the plug

Green wire to "u" prong green screw
Black wire to vertical copper prong
White wire to silver horizontal prong

View attachment 219824

Feel free to correct me if I go wrong I have no intention of plugging in tonight anyway





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[passedpawn]

I put a switch on my patio that is very similar to what you're doing there.

 

[Zibe]

Pawn that looks exactly like what I'm doing except I'm sticking with 120v

Just wired up the boxes hope this is correct:
1)White wire I just ran straight down to the outlet and put it on the top silver screw
2)Black goes in top of switch then another black goes from bottom of switch to top copper screw on outlet
3)Green I just wire nutted one going to each green ground screw


I was using this diagram:

Except that shows also running a jumper to the box ground screw-is that necessary? Electric guy at lowes said just wire it to the ground screws on the switch and outlet.

Thanks again for the help.


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