1

I have a Samsung WF45K6500AV front load washer that trips the breaker when it is powered on.

To give some background, initially, I had a similar problem to this post here. My washer all of a sudden started tripping the breaker when plugged in. I took the machine apart and did not see any evidence of a ground fault. Like in the linked post, I realized that when I had CN11 disconnected from the main PCB, I was able to plug in the machine without tripping the breaker. However, it was not able to be turned on.

Out of frustration, I ordered a new main PCB and replaced the old one. In doing so, I was able to now plug in my machine without tripping the breaker. I tested with the old PCB and to my surprise, it now was able to be plugged in without tripping the breaker, even when CN11 was connected. However, at this point, attempting to power on the washer would still trip the breaker. After some testing, I discovered that with CN5 disconnected, I could actually power on the washer without tripping the breaker.

Some other notes:

  • Voltage from wall is 120V.
  • Voltage going into noise filter is 120V.
  • Voltage exiting noise filter is 120V.
  • Voltage going into noise filter on PCB is 120V.
  • Voltage exiting noise filter on PCB is 120V.
  • Voltage going into CN11 (PBA Power Supply) is 120V.
  • Voltage going into CN5 (AC Power Source) is 120V.
  • When CN5 is connected, and then if the machine is powered on, the breaker trips.

Here are some diagrams of the PCBs and the connectors on them. CN11 is on the main PCB and CN5 is on the inverter PCB. enter image description here enter image description here enter image description here enter image description here

1
  • Exactly what kind of breaker is being tripped? With a suitably long extension cord plug this machine into different circuits with different types of breakers and see what happens. Could it be that the breaker is faulty? Our Samsung top loader is plugged into a dedicated 20 A circuit wired in 10 AWG aluminum through the original GE standard half-height breaker from 1970. The duplex receptacle is probably a CO/ALR installed in 1978. The "new" requirements of GFCI/AFCI for washing machines seems to be causing some problems. Commented Jul 13, 2023 at 10:15

1 Answer 1

3

Well obviously, you have the hang of troubleshooting at the module level. So carry on.

Anyway, start at the circuit breaker. See if it has a way to indicate whether the trip is due to overload, short circuit, or ground fault. This is to spare you time troubleshooting the wrong fault :)

If it is a ground fault, here's what's happening. The GFCI breaker is observing current on both hots and neutral, and expecting currents to be equal and opposite - that is, every electron that goes up one wire, comes back one of the other two - the other hot if it's a 240V load, or the neutral if it's a 120V load. The problem arises when there's a miscount. That means that current is traveling a fourth path, presumably shocking a human or trying to start a fire. In practice, the fourth path is going to be either the ground terminal on the power plug, metallic water piping, or the water itself.

Normally AC power (hot and neutral) should be isolated from ground. So on any given module, a simple ohmmeter measurement could be done from hot and neutral to anything tied to ground. However, a common DVM uses a very low test voltage (all the better not to damage electronics), and some ground faults behave like a voltage breakover (VBO) device, where they do not flow current until a certain voltage. This means a plain ohmmeter's test cannot validate a component, only condemn it. A megaohmmeter with a high test voltage can be used; however these can damage electronics.

I would stick to the narrowing-down approach you are using. You can also "lift" ground either on a component or on the whole machine to see if that is the fault path. The easy way to lift ground on a whole machine is to obtain a 2-prong/3-prong "cheater" and tape over the ground tab so it cannot contact the cover plate screw. This should only be done for diagnostic testing. Defeating ground on a device as a permanent solution to GFCI tripping reduces safety protection - while the situation is not terrible because of the presence of GFCI, the machine is still faulty.

enter image description here

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.