double pole breaker trips all the time

First of all, I have a dumb question: does this white double pole breaker offer 20A or 40A (20A+20A as labeled) in total?

This double pole breaker controls both pool pump and washer (washing machine).

It trips all the time, and one time, the outlet for the washer was even burned out. Sometimes pool pump would suddenly stopped and lost power.

For the pool pump, it uses 10 Amps max, and for the washer, it uses 20 Amps max. Also, the pool pump was recently replaced and has some air inside sometimes.

Anyone know what might be the issue here?

• washer is a washing machine or this is something for your pool too? – Fresh Codemonger Apr 1 at 20:05
• @FreshCodemonger its a washing machine. i also updated the description above – Dude from SF Apr 1 at 20:11
• 20A on each of two circuits. It may feed a MWBC: two separate 120V circuits, fed from different incoming power legs, with a common neutral. It's a GFCI (TEST button and fine print on the label.), so I'd start hunting on the pool side for something wet that ought to be dry. – HABO Apr 1 at 20:17
• @HABO thanks for answering. you just mentioned its 20A on each of the two circuits. But the answer provided below by Ecnerwal said its 20A for all? – Dude from SF Apr 1 at 20:21
• We're saying the same thing, but perhaps not making it clear to you. Have a look at this (tiny, sorry) diagram. If you squint you can see that the two incoming legs (red & black) go through the breaker to the red and black branch wires. The trick is that L1 and L2 are 120V to neutral, but out-of-phase so that L1 to L2 is 240V. Each pole of the breaker will only pass up to 20A. You can draw up to 20A @ 240V L1 to L2 OR 20A @ 120V on L1 and L2. Or combine them: 15A @ 240V leaves 5A @ 120V times two. Any better? – HABO Apr 1 at 23:20

This is a 240V (2-pole) breaker. Given the 20A size, it is perfectly legal for it to feed both 120V and 240V loads, and I suspect the pool pump is a 240V load.

A 20A 240V/2-pole breaker has two poles (legs) of 20A each.

A 120V load can draw off one leg and neutral, and it will draw the amps it says.

A 240V load will draw off both legs at once and will draw the amps it says.

So for instance, your pool pump draws 10A from L1 and 10A from L2.

• L1: 10A pool pump. 20A washer. Total 30A
• L2: 10A pool pump. Total 10A.

30A is more than 20A. Whoops!

Or, it could be a ground fault problem

That particular breaker is a GFCI (Ground Fault Circuit Interruptor) breaker. It is looking out for ground faults, which is leakage from the places power is supposed to be, to places power is not supposed to be.

Such leakage is exceedingly common with electrical machines that handle water.

It can also happen in wiring, particularly outdoor wiring.

If you are getting trips when the washing machine is not running, this is likely the problem.

You would need to eliminate one appliance at a time by unhooking all of its wires (hot(s) AND neutral) from the system. You must unhook neutral or the test will be invalid. You don't need to unhook safety ground. If you unhook an appliance and the problem goes away, that appliance is faulty.

"I have a question: does this white double pole breaker offer 20A or 40A (20A+20A as labeled) in total?"

20A - At 240V.

If your washer draws 20A and your pool pump draws 10A, hardly surprising it would blow, since that would be 30A draw. So it would be reasonable to expect it to blow any time both are on at once, or at least any point in the wash cycle where your washer is drawing full load and the pool pump is on.

This is also a moderately blatant code issue, since the power for the washer and dryer is not supposed to share with any other room/function.

• the washer is plugged to 120V regular outlet. How come it becomes a 240V in the panel? @Ecnerwal – Dude from SF Apr 1 at 20:22
• It could be a single pole 20 amp but the code requirement for the laundry is somewhat newer. But if a single pole I would agree. The double wide GFCI’s that were single pole are 20+ years old. As is the original requirement for a laundry circuit. 99? – Ed Beal Apr 1 at 20:28
• Multi-wire branch circuit. 2 hots, 1 neutral, hot to neutral is 120V, hot to hot is 240V. If the washer outlet was burned out, I have to wonder if there's a dubious connection on the neutral line, which could expose it to higher voltage. Neutrals on MWBCs are supposed to be pigtailed to reduce the odds of a problem of that sort, but sloppy work happens. What voltage is the pool pump? – Ecnerwal Apr 1 at 20:29

First that is a 20 amp circuit it could be 240v but sounds like 2 each 20 amp 120v circuits that are both protected by a 20 amp breaker (not the same as 40 amp).

That is a GFCI breaker (I can just barely read ground fault on the tag) . Having multiple loads like the washer and pool pump suggest it is a multiwire branch circuit.

Multi-wire branch circuits have become less popular because because of GFCI requirements and false tripping.

The receptacle that failed probably back stabs were used (although 20 amp should not have back stabs I have found this and loose connections to melt a device). because of the small contact area the connection was not a good one that overheated to the point of melting down. But either circuit drawing +20 amps will cause this to trip.

Or a ground fault with a 5ma value can cause this to trip.

1 problem with GFCI’s on motor circuits is they measure the current on the line and the neutral if there is an imbalance of greater than 5ma or 0.005 amps they trip.

Motors create an imbalance in the voltage and current and by themselves and can sometimes cause false trips by themselves, but having motor loads on both sides can make the problem worse.

Today’s code requires the washing machine to be on its own circuit, I have had problems with gfci’s and my state allows me to change that dedicated circuit to a standard breaker. I would check your state rules and if the washer is close to the panel I might convert to separate circuits. The pool will still need GFCI protection but being on a separate single pole breaker with a weather resistant GFCI outside where it can be reset is what I would do and there will be less tripping.

If your state still requires a GFCI device and you don’t want to replace wiring. I have found in this type of case a separate GFCI device in each place(1 at washer and 1 for the pool) with and a standard double pole breaker to have less trips, however having a common neutral they still may trip.