My Tractor Forum banner

Tripping breaker when running 2 electrical heaters

4901 Views 35 Replies 17 Participants Last post by  Curly69
I had my mancave wired up earlier this yr. The mancave is about 80 ft from the house and the main breaker. He ran 2 alt from the main breaker to the mancave where he put a 150 amp box inside there. It has 5 breakers, one running the lights inside the cave and one running the receptacles. The other 3 are running lights and receptacles in the lean to's and storage sheds.

In the cave there are 6 receptacles and one 8 ft light. I have a tv, direct tv reciever, microwave, refridge, pc, pc spkrs, monitor, and printer plugged up. I was using one small electrical heater to heat right by me when on the pc. Im really only in there to check emails in evenings when get off usually no more than 1-2 total hours in wkdays and on wkends back and forth some maybe checking email. I need a tv since the pic tube is bout gone on my old projection so im not in there watching tv right now.

Anyway, I have another radiant type elec heater that i put in there on Xmas day cause i had a few guys in there watching some of the game.Both heaters were running but in different receptacles. After about 10 minutes, the breaker for the receptacles tripped. I tried it again yesterday and it tripped again. It won't do that with just one heater running. I really dont need the microwave and printer plugged in all the time just when i use them which is rare. I am thinking about maybe getting a AC/heat window unit next yr so hopefully that would be fine in there. Thoughts guys
See less See more
1 - 20 of 36 Posts
What size are the breakers; 15 amp or 20 amp? It sounds to me that the addition of the second heater exceeded the amperage of the breaker causing it to trip.
I think you need to divide the receptacles and add another breaker.
Dave
yeah sounds like you went past the amps on the breaker. the microwave and printer dosnt realy use power when not on. because all 6 plugs are on the same breaker your pushing the limits with the tv and two heaters on. the best thing to do is put another breaker in the best would be 20 amp and use that just to run an eletric heater and then put the other heater in another plug.
See less See more
yeah sounds like you went past the amps on the breaker. the microwave and printer dosnt realy use power when not on. because all 6 plugs are on the same breaker your pushing the limits with the tv and two heaters on. the best thing to do is put another breaker in the best would be 20 amp and use that just to run an eletric heater and then put the other heater in another plug.
thanks guys, wish i knew this while he was doing the work.I think I can handle that myself though. Not sure if the breaker is a 15 or 20. If its just a 15, suppose i just swap it out for a 20?
See less See more
or if not a 20 how big can i go for those 6 receptacles?
NO you can't just swap it for a 20, the breaker protects teh wire and is sized for that. a 20A breaker can allow 14g wire to overheat and catch fire, so unless you are 100% certain that all portions of the circuit are rated for at least 20A you must leave the 15A in there.

even if you did have a 20A circuit, it would trip on 2 heaters. a breaker won't trip at the exact instant you pass 20A, but once it heats up from it it does due to the thermal protection portion of teh breaker. you are likely pulling closer to 25-30A on that circuit and after 15 minutes or so it heats to the point the breaker trips. install 1 or 2 more circuits and put the heaters on them, leaving the original circuits for other things.

BTW, i can't think of a reason any professional electrician would wire all recepts on 1 circuit and lights on another any more. i can see seperating them just so you have light if a breaker trips, but he should have put at least 2 circuits for recepts. heck when i wired my shop i have 6 different 20A recept circuits in a less than 20x20 building, no matter where you stand along a wall you have access to 3 different 20A circuits with no more than a 6' cord. heck, i even put 3 up in the ceiling for "just in case".
See less See more
NO you can't just swap it for a 20, the breaker protects teh wire and is sized for that. a 20A breaker can allow 14g wire to overheat and catch fire, so unless you are 100% certain that all portions of the circuit are rated for at least 20A you must leave the 15A in there.

even if you did have a 20A circuit, it would trip on 2 heaters. a breaker won't trip at the exact instant you pass 20A, but once it heats up from it it does due to the thermal protection portion of teh breaker. you are likely pulling closer to 25-30A on that circuit and after 15 minutes or so it heats to the point the breaker trips. install 1 or 2 more circuits and put the heaters on them, leaving the original circuits for other things.

BTW, i can't think of a reason any professional electrician would wire all recepts on 1 circuit and lights on another any more. i can see seperating them just so you have light if a breaker trips, but he should have put at least 2 circuits for recepts. heck when i wired my shop i have 6 different 20A recept circuits in a less than 20x20 building, no matter where you stand along a wall you have access to 3 different 20A circuits with no more than a 6' cord. heck, i even put 3 up in the ceiling for "just in case".
yeah had i known then what i know now i would have made sure he did that. I will call him to see how he did it. He moved from SC to Georgia about 8 months ago.
See less See more
David G is right; you can't just swap in a bigger breaker. You have to take into account what you are supplying the breaker box with (size of wire, distance traveled, etc.) along with what you intend to do at the new location. Heaters are on the top of the list of current draw devices; and running two of them surely exceeds your circuits limits.

I think you need to make a drawing of what you have now, including the set-up at your house before you added anything. It may be you can't add a man cave safely without a separate drop from the power co.

If you determine you can add the load of the man cave, you need to figure the size of the supply wires to the new box. Having a 150 amp box only means it can safely distribute 150 amps of service if it is safely supplied and divided correctly.

There are formulas for figuring power transfer through specific wire sizes over varied distances. The greater the distance - the larger the wire needed to prevent loss and other problems like overheating and fire.

Once you get power to the cave - you need to divide it properly to prevent problems. Lights and basic outlets are pretty easy. Other items with start up current draw need more consideration. Compressors and other items need larger wire coupled to a larger circuit breaker. Lights are usually run on 15amp circuits with 14g a wire. Outlets are usually run on 20amp circuits with 12g a wire. (the smaller the wire ga size - the larger the wire).

Once you have all that figured out I would add a 50% safety cushion that also covers minor expansion.

It all adds up - that's why knowing what's there beforehand is important.

One way to do it is to start at the man cave and work backwards. Total up the constant current draw from all the items you wish to power. Keep lights and outlets on separate circuits. Then add the start-up current draw from those devices that have a large one. Do one circuit at a time. The total will exceed the supply because you don't usually have all the devices on at once.

Compare those numbers to the circuits you have now. You may be able to adjust some things at the breaker box. If you breaker box is the split type, make sure you keep the load balanced between the two input legs.
See less See more
David G is right; you can't just swap in a bigger breaker. You have to take into account what you are supplying the breaker box with (size of wire, distance traveled, etc.) along with what you intend to do at the new location. Heaters are on the top of the list of current draw devices; and running two of them surely exceeds your circuits limits.

I think you need to make a drawing of what you have now, including the set-up at your house before you added anything. It may be you can't add a man cave safely without a separate drop from the power co.

If you determine you can add the load of the man cave, you need to figure the size of the supply wires to the new box. Having a 150 amp box only means it can safely distribute 150 amps of service if it is supplied and divided correctly.

I suggest you add a breaker in your main service box and not just tap into the main feed.
There are formulas for figuring power transfer through specific wire sizes over varied distances. The greater the distance - the larger the wire needed to prevent loss and other problems like overheating and fire.

Once you get power to the cave - you need to divide it properly to prevent problems. Lights and basic outlets are pretty easy. Other items with start up current draw need more consideration. Compressors and other items need larger wire coupled to a larger circuit breaker. Lights are usually run on 15amp circuits with 14g a wire. Outlets are usually run on 20amp circuits with 12g a wire. (the smaller the wire ga size - the larger the wire).

Once you have all that figured out I would add a 50% safety cushion that also covers minor expansion.

Yeah we put a I forgot what size breaker into the main house box(outside) at the house. We ran 2 alt 80 ft from the main box to the cave. We used either 10 or 12 guage wire i believe to run everything from the receptacles and lights to the breakers.

the cave is only an 18 x21 so the longest distance would be about 20 ft. He daisy chained the receptacles I'm thinking. I'm thinking the 2 receptacles on the other side I can just bypass those from the receptacles and run 2 new wires, one wire to each receptacle and just put in 2 new breakers. One receptacle would be fore the window AC/heater that i will install and the other will be for whatever else and if i wanted to not run the AC sometime and just run an electrical heater i can at that spot.
See less See more
I'm not sure what you mean by 2 alt. My shop is 40 x 60. Supply wires from my main panel are approx 125'. I ran 4ga wires with a 6ga ground. I ran 220 out there so there are 4 wires total. 1 6ga ground, 2 4ga supply voltage wires, and 1 4ga common. They feed a 100amp breaker in the box in the shop.

From there I have separate lighting circuits (14ga 3 wire) feeding 32 florescent 4' 2bulb lights. Then separate 20amp circuits feeding outlets.

The supply wiring to the shop all run through underground conduit. I also ran another pvc conduit for phone and cable, but I don't use it much, and probably wouldn't do it again.

It's not the number of outlets or lights you have; it's the number in use at any one time that matters.

Running even 10g a wire 80' isn't enough in my opinion. I think you really need to find out what you have first. What size supply breaker, what size the wire really is and how long the run is.
See less See more
I'm not sure what you mean by 2 alt. My shop is 40 x 60. Supply wires from my main panel are approx 125'. I ran 4ga wires with a 6ga ground. I ran 220 out there so there are 4 wires total. 1 6ga ground, 2 4ga supply voltage wires, and 1 4ga common. They feed a 100amp breaker in the box in the shop.
So if you have a 100A 220V sub panel in the garage feeding everything you just have a small wiring issue and not a feed issue.

From there I have separate lighting circuits (14ga 3 wire) feeding 32 florescent 4' 2bulb lights. Then separate 20amp circuits feeding outlets. What size wire feeding the Outlets? If it's #14 then the breaker is oversized! You may cause a burnout or fire/short in the circuit!

The supply wiring to the shop all run through underground conduit. I also ran another pvc conduit for phone and cable, but I don't use it much, and probably wouldn't do it again. OK for your shop..

It's not the number of outlets or lights you have; it's the number in use at any one time that matters. 5 outlets max per circuit. Also another wiring mistake by some DIY'ers is to hook both of the main wires through the outlet so any outlets farther down the circuit will feed through the little metal tabs between the outlet's side screws! These little tabs will heat up and cause bad things to happen if a large load is hooked up farther down the circuit. :Stop: Always hook the wires together and run a jumper from the wire to wire connection to the plug in each box. That will ensure proper power transfer to all outlets throughout the circuit with minimal heatup hazards.

Running even 10g a wire 80' isn't enough in my opinion. I think you really need to find out what you have first. What size supply breaker, what size the wire really is and how long the run is.
So to reinforce flyrv9's concern you seem to have a lot of things hooked up and if you are popping breakers you are pulling too much load on the wiring circuit you have installed- what size wire do you have is the important question! As you say there is 2 (ought?) AWG to a 150A supply panel (?) you have a poor supply connection or just have wiring issues within your shop to deal with. Fire back with more information and advice can be given..:trink40:
See less See more
If you've go an 80' run I'd personally go no smaller than 8Ga. Probably more like 6 to be safe. What's 2 alt? 2AWG? If that's what you ran you ought to be real safe with that. Split them receptacles up to different breakers. 14ga wire 15A- 12ga wire 20A
Joe
I'm not sure what you mean by 2 alt. My shop is 40 x 60. Supply wires from my main panel are approx 125'. I ran 4ga wires with a 6ga ground. I ran 220 out there so there are 4 wires total. 1 6ga ground, 2 4ga supply voltage wires, and 1 4ga common. They feed a 100amp breaker in the box in the shop.

From there I have separate lighting circuits (14ga 3 wire) feeding 32 florescent 4' 2bulb lights. Then separate 20amp circuits feeding outlets.

The supply wiring to the shop all run through underground conduit. I also ran another pvc conduit for phone and cable, but I don't use it much, and probably wouldn't do it again.

It's not the number of outlets or lights you have; it's the number in use at any one time that matters.

Running even 10g a wire 80' isn't enough in my opinion. I think you really need to find out what you have first. What size supply breaker, what size the wire really is and how long the run is.
4ga on a 100amp breaker WOW that is crazy
See less See more
Ok might be close if it's copper
Time for a licensed electrician to check the whole problem out before the 'man cave' becomes a 'swimming hole with no roof'. Could be a simple fix, or it could be a disaster just waiting to happen.
You've got too much invested in there to mickey mouse a supposed fix.
I am licensed electrician and you should have those heaters on seperate circuits no matter if is a 20amp or 15amp circuit 2 heaters are too much current draw for either
small electrical heaters are usually 1500w, which means they will pull 12-13 amps each. No way they need to be on same circuit.
Just run a new wire box and breaker just for the heater...
I am licensed electrician and you should have those heaters on seperate circuits no matter if is a 20amp or 15amp circuit 2 heaters are too much current draw for either
for right now though i should be fine right with just one heater cause its not tripping it with just one running, and it doesnt run all that long anyway cause im only in there to check emails and stuff. Have to get another tv before i will be watching tv and stuff but yeah i will just either add 2 more recep and 2 more breakers or just use 2 of the receptacles and run those 2 to separate breakers.
See less See more
Sounds like a plan to me
1 - 20 of 36 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top