Does a breaker have a minimum operating current?

Question

For context: The breaker for my mom's dishwasher keeps tripping. Apparently many people in the neighborhood are having the same issue. An electrician that lives there said those breakers are "super sensitive" (hearing this third-hand). We've replaced the breaker a few times, and it will work fine for 5-6 months until it trips and won't stay closed.

It's a 20A breaker, and I think I'd like to try increasing it to 25A. However, when discussing this with a friend, he said, "Normal dishwashers aren't strong enough to be able to use a 25A breaker," and that it might not draw enough current.

My question is this: does a breaker have a minimum current that it can output? Setting aside the risk of not tripping for a damaging current level, would a 50A breaker be capable of powering a circuit that only draws 10mA?

Edit: The breaker we replaced it with last time is an Eaton CHFCAF120PN. I don't see anything about it having GFCI on the spec sheet, but it does have a "test" button on it.

Edit 2: Just got to my mom’s house and verified some info. Apparently it’s been a different breaker we’ve replaced every time. First the den outlets, then the microwave, and now the dishwasher circuit is acting up. So the current breaker on the dishwasher is the original one (and does have the AFCI). Also, the current breaker is not tripping, the dishwasher just doesn’t have power sometimes when she goes to start it. This is independent of when a wash cycle is actually run. She gets it to work again by pressing “test” to trip the AFCI and then turning the breaker back on. When it has power, the dishwasher runs complete cycles. I’ll continue to troubleshoot with it and figure out what’s going on. The main point of this post was to get educated about the “wetting current” to activate the breaker, but figured I’ve give some context in case someone already knew a solution to my problem.

Answer 1

This doesn't technically answer the question that was asked, but it does answer the question that probably should have been asked in this scenario:

The breaker you've mentioned has an AFCI built in. It's likely the AFCI is what's tripping, especially considering you say your neighbors have replaced the breaker (likely with a cheaper non-AFCI model) to get rid of the problem.

You should never bypass an AFCI that is nuisance tripping. Arc faults are among the most likely causes of electrical fires, and you really don't want them to go unnoticed. What you need to do is figure out why there is an arc fault on that circuit; it could be a problem with the dishwasher, or it could be a problem with shoddy wiring in your walls. You should have a qualified electrician look at it and see if they can identify the cause. If your home is new enough that it's still under the builder's warranty, see if you can make a claim on that. You might want to talk to the builder--or the electrician who installed that circuit if it's not original--regardless.

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And now, to answer the question actually asked, though I think the answer won't be useful:

Switches in general do have a minimum operating current, called the wetting current; this is the current that is guaranteed (in conjunction with a minimum wetting voltage) to break through any oxides or other dirt or corrosion that may build up on the switch contacts. Below this current, which is typically on the order of a handful of mA, or a handful of μA for special low-level switches, they are not guaranteed to close correctly. The exact current and voltage required depends on the materials the switch is made out of as well as the mechanical design of how the switch contacts actuate. Once the wetting current has flowed through the closed switch for a bit, though, lower-level signals will typically continue to pass just fine until the switch is opened and closed again.

Typically, wetting current is not a concern for mains circuit breakers; at least, I've never seen a case where it was. I wouldn't be surprised if the parasitic capacitive load presented by the wiring in your walls is sufficient to overcome any wetting current issues.

Answer 2

It's a 20A breaker, and I think I'd like to try increasing it to 25A

Circuit breakers in your main electrical box are meant to protect the wiring in your house from overheating and starting fires. (Some circuit breakers are also GFCI devices, i.e. ground fault current interrupters meant to protect you from shock in the case of ground faults). The electrician who installed the circuit breakers should have done so knowing the rated ampacity of the wires in your dwelling. Therefore, you should NOT replace the existing circuit breakers with ones with a higher rating unless you know for a fact (usually per a licensed electrician) that the wires have a larger ampacity than the existing breakers. If you do replace the breakers with ones that are rated for a higher ampacity than your wires, you

• risk a fire in your house
• risk that your insurance company will not pay for any damages to your house

Answer 3

No, breakers don't have a minimum current.

The ones powering your mains sockets may be fully without no load plugged in, or you might have a 0.1W night light, or 10A heater.

Since it is a AFCI with a test button, it means that either the washer is faulty and trips the AFCI with too much leakage current, or the wiring between AFCI and washer is faulty, including the sockets between them.

Or if your local building code allows, don't use a AFCI then.