I was looking at my load center breaker panel to see where to put a couple of breakers dedicated to space heaters. I have a spare slot where I intend to put a tandem 15A breaker. I'm going to move a 15A load from the other side of the panel (it's 50A) to this new breaker so I'll have only one heater on each hot leg - better for when I'm running my generator.Anyway, my question is: is there any performance / safety difference between a full sized breaker and a tandem? Both my air conditioners are on full-size 20A breakers but there are also a couple of 15A/20A tandems.

No Difference from a performance or safety perspective. You can also install a sub panel but that would be overkill.

Both my house and my RV use tandem breakers with no problems.

No difference. Might as well spend a few might as well spendca few minutes phsses to neuteal voltage ensuring your loads are, in reality, balanced.

I have a tandem and it has worked flawlessly. However when I bought it hte (retired) electrician at Lowes said they were prone to nuissance tripping.

If you're running "one heater on each leg", you should use two single breakers rather than a tandem. You can easily make sure each breaker is on a different leg. If you're using a tandem breaker with two potentially unbalanced 110v loads, you can cause problems.

Full size breakers vs. tandem (double) breakers?

39 Replies

westend
Explorer
Sep 28, 2016
DavidP wrote:
Stefonius wrote:
If you're running "one heater on each leg", you should use two single breakers rather than a tandem. You can easily make sure each breaker is on a different leg. If you're using a tandem breaker with two potentially unbalanced 110v loads, you can cause problems.

Taking the single out and adding a tandem will put each heater on its own leg. He will not need two single breaker since the tandem will give him two legs/circuits. Balance will be no different than having two single breakers.
Are you sure about this? Most tandem breakers I've handled only attach to one load center bus.
Edit: This may not be true of a 50 amp RV load center. I use a residential load center in my trailer so don't have a specific RV load center.

And, there is no reason not to balance the amount of potential draw between the two legs of the service. Why would you want to pull everything off one leg?
ScottG
Nomad
Sep 28, 2016
There is no need to "balance loads" on a 240V panel unless your Xfmr is tased (not likely) or your using an incerter or gen.
You can literally have everything on one side and nothing on the other and it will still work fine assuming appropriate sized conductorsand aren't exceeding any specs.
DavidP
Explorer
Sep 28, 2016
Stefonius wrote:
If you're running "one heater on each leg", you should use two single breakers rather than a tandem. You can easily make sure each breaker is on a different leg. If you're using a tandem breaker with two potentially unbalanced 110v loads, you can cause problems.

Taking the single out and adding a tandem will put each heater on its own leg. He will not need two single breaker since the tandem will give him two legs/circuits. Balance will be no different than having two single breakers.
joebedford
Nomad II
Sep 28, 2016
Stefonius wrote:
If you're running "one heater on each leg", you should use two single breakers rather than a tandem. You can easily make sure each breaker is on a different leg.
I only have one slot available so I can't add two breakers.
If you're using a tandem breaker with two potentially unbalanced 110v loads, you can cause problems.
I don't understand this - please explain.
Stefonius
Explorer
Sep 28, 2016
If you're running "one heater on each leg", you should use two single breakers rather than a tandem. You can easily make sure each breaker is on a different leg. If you're using a tandem breaker with two potentially unbalanced 110v loads, you can cause problems.
greenrvgreen
Explorer
Sep 28, 2016
I have a tandem and it has worked flawlessly. However when I bought it hte (retired) electrician at Lowes said they were prone to nuissance tripping.
MEXICOWANDERER
Explorer
Sep 28, 2016
No difference. Might as well spend a few might as well spendca few minutes phsses to neuteal voltage ensuring your loads are, in reality, balanced.
tenbear
Explorer
Sep 28, 2016
Both my house and my RV use tandem breakers with no problems.
DavidP
Explorer
Sep 28, 2016
No Difference from a performance or safety perspective. You can also install a sub panel but that would be overkill.

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Full size breakers vs. tandem (double) breakers?

39 Replies

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