1

I have 2 bedrooms in my house that are supplied by a single 15A breaker, but both bedrooms are being used as home offices with (in one case) a significant amount of computer equipment in it.

enter image description here

The problem is that I have had a handful of trips of this particular breaker over the last year, so I am looking for the best solution to my problem. FWIW both bedrooms are immediately above the breaker panel, and there are several spare slots in the panel.

Is the best solution:

  1. Split the bedrooms into their own circuits?
  2. Upgrade the breaker to say 20-30A?
  3. Replace the breaker with one the same size, that might be less "twitchy"? (if that's a thing)

Note that I will be hiring a licensed electrician to do the actual work. I'm just trying to get ideas of what the best approach should be.

2
  • 3
    #1 is the best, but probably most expensive, depending on how the cables go though the walls. #2 is a fire waiting to happen. #3 is iffy if it would help, breaker choice is quite limited, must be listed to go into that panel.
    – crip659
    Jun 29, 2023 at 0:44
  • 1
    Does that breaker give any fault indication for which of several reasons it tripped, when it tripped? Some do, and that can be diagnostic (so if you're running down overcurrent as your question assumes, but it's really tripping for an arc fault, you'd be not solving the actual problem.)
    – Ecnerwal
    Jun 29, 2023 at 1:19

4 Answers 4

6

Never overload!

You've already stated the breaker is tripping because you are overloading it. NEVER do that. If you are doing something to overload a breaker, stop at once and discontinue. Every device has a data nameplate which tells you how much power it requires. You can read that nameplate and add them up.

If you can't power all that equipment in a bedroom maybe move the home office to somewhere with a surplus of power. One person we helped was in a basement home office with only one 15A circuit. In photos we noticed the service panel was in the room and had an "electrician's receptacle" on a dedicated 20A circuit. That was easy: use that!

  1. Replace with a breaker that is less "twitchy"?

No, we already know why it's tripping, you are overloading it. A less twitchy breaker would fail to do its job.

Never over-fuse!

Why stop at 30A? Put a 60A in there and it'll never trip LOL. "Oh noes, I would never do that, it would degrade my fire protection" well, so will putting in a 20A. The 15A is there to avoid overloading the 14 AWG wire.

The largest circuit that can have normal outlets is 20 amps which in turn requires 12 AWG wire. That is generally my advice because you can put more loads onto 20A circuits than 15A. The price isn't that different.

Expand at will

Bedrooms require AFCI breakers. Siemens is the only maker of AFCI tandem breakers.

If you want to add one or two 20A circuits, you can do that just fine. I would do that and then run two additional 20A circuits, placed so each circuit has 1 or 2 outlets in each bedroom. That gives each bedroom access to all 3 circuits. That way you don't have a situation where one 15A circuit and one 20A circuit is not enough and you really need a third, but sadly it's on the other side of the bedroom wall.

1
  • I had a licensed electrician look at my project today. He actually hinted that replacing the AFCI with a standard breaker could be a solution to sensitive tripping. I will not be using this guy.
    – Peter M
    Jul 10, 2023 at 22:07
3

Put the computers on a UPS (Uninterruptible Power Supply) and the direness of nuisance trips (or actual power outages) goes way down.

You can't "upgrade to 30A" unless you are running a dedicated circuit on new 10 AWG wire to a TT-30 or L5-30 outlet (the latter of which some of the beefier and pricier UPSes plug into.) You can't plug your 15/20A devices into that outlet, but you could plug them into a UPS that plugged into that outlet.

You can't (as already mentioned) upgrade from 15 to 20A unless you have 12 AWG wire everywhere on the circuit, or replace all the wire on the circuit to be 12 AWG, first.

Your electrician will likely have to run some new wire anyway to even split them to their own 15A circuits, at which point you might as well run a pair of 20A circuits to new outlets and call it done well, or a single new 20A to some new outlets which will likely be adequate. Leave the original circuits and outlets in place and add to them.

2

You can only upgrade the breaker if you are 100% certain that all wires in that circuit are of at least the appropriate gauge (12 or thicker for 20A). You cannot put a 20A outlet on a 30A circuit.

Splitting the bedroom circuit is probably the easiest solution if the wire run isn't horrible.

And/or you can run a new circuit dedicated to that computer equipment and keep the other outlets as is. 20A will be plenty unless you are running actual server hardware.

2

Splitting the bedrooms to separate circuits is the best choice, because that give each room maximum current draw capability. This idea requires breaking one of the rooms from the other and running a separate independent cable to the circuit panel, which may require cutting holes in walls. The new circuit will probably require the same kind of CAFCI breaker you have now to meet code.

Increasing the existing breaker to 20 amps is possible only if all the wire to and in the bedrooms is 12 gauge copper or bigger (check on the required gauge if the wire is aluminum).

A 30 Amp breaker upgrade is dangerous, against code, and not good.

You can tell if the breaker is "twitchy" by testing why it trips. If the total current draw approaches or goes over 15 amps, then it's probably overcurrent protection kicking in. If the current is lower than 12 amps all the time and the breaker still trips, it could be the AFCI protection, meaning there's a loose connection in the wires to the rooms, and a fire may be imminent. Or it's slightly possibly a bad breaker. If you switch the breaker and it keeps tripping on less than 12 amps, it's a loose connection. If the breaker stops tripping on less than 12 amps, it's the breaker.

If you have another 15 Amp CAFCI breaker in the panel that is behaving normally, and you are careful and know what you're doing or can get instruction or help, you can swap the wires going to the two breakers, and see if the tripping also swaps.

1
  • 12 AWG aluminum for 15A, 10 AWG Aluminum for 20A, should they be so unfortunate.
    – Ecnerwal
    Jun 29, 2023 at 1:10

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.