Washing Machine Tripping electrics

[tan159753]

I have a roughly 7 year old Ariston Margerita av838 Washer Dryer. Its a fairly basic model.

The machine washes and rinses the clothes ok but after the spin cycle has finished and the timer moves on to the final setting (door release I think) it trips the RCD of the main electric board.

After using it like this for a few weeks, the motor stopped spinning altogether and replacing the bushes in the motor fixed the motor spin problem. However, the tripping on shutdown still remains.

What is causing this trip? I have had a good look at all the wiring and cant see any shorts/sparking.. I have even removed the wires from the door lock mechanism but it still trips on shutdown. I doubt its the motor because it washes and spins ok.

Any ideas?

 

[tan159753]

Thanks for ALL the replies not

Anyway, after disconnecting various items one at a time, I have found that when I take the wire off the heater element for the dryer, I get no trips.

However when I took apart the machine and extracted the heater, it was fairly warm so I assume it is still working?? The resistance shown across the coil is virtually 0 ohms. Is this normal? I was thinking maybe the coil was shorting with the casing causing the mains to trip. Or maybe the temperature sensor next to it is not working hence the coil just heats and heats till it trips?

Any ideas - I dont want to rush out and buy another heating element to find that the problem is elsewhere.

 

[Leccy758]

Check the insulation resisitance to earth of the heating element when it is hot and cold. Should be more than 2 meg ohms (need an Insulation resisitance tester not a multimeter for this)

Not uncommon for them to go low in value when they heat up and trip an RCD.

The resisitance of a heating element should be around 27 ohms (make sure the meter is on a low setting)

 

[tan159753]

I have changes the dryer heating element and now thankfully it doesn't trip.

BUT

The main motor hardly spins now again just like before I changed the carbon brushes!! After I changed the brushes, the motor started to spin fast in a test run. When I put in a looad of clothes, its back to motor struggling to spin with lots of sparking going on where the brushes meet thee slip rings of the motor.

I have taken the motor out and given it a good blast with air ans have thoroughly but carefully cleaned the slip rings where the carbon brushes meet. Does this mean the motor is knackered or am i missing something?

 

[Leccy758]

Did the motor (wash motor I presume) spin up fast straight away or did it do some slow rotations first.

If it span up right away (try it on a spin cycle if you are not sure) check the tacho on the motor (centre of the motor at the brush end) these can come loose and the wires can get abraded, the motor plug connections could be loose (the circuit board gets feedback from the motor so it can sense the speed the motor is running at)

 

[tan159753]

I took the tacho thing off and the motor spun at full speed. I fitted another tacho from a working machine but its just the same. Spins s l o w l y with the tacho on but when you take the tacho it spins at full speed. I guess this means the speed controller pcb is knackered.

What I dont understand is that when I first changed the bushes, the machine spun normally on a test run.

I'm gonna have to give up on this as the machine is 17 years old. I was really trying to avoid buying a newer one. Reading the reviews most newer machines, especially the ones with fancy displays just don't like working.

 

[tan159753]

I was just wondering. Could the fast slow spin be due to an OUT OF BALANCE sensor thingy (Anti-Balance Controls) ?

The motor starts to spin but just as it gains speed it cuts out but then starts up again just as the motor is slowing but never gets up to speed.

Where are these OOB sensors anyway?

 

[zipper]

There are no separate "sensors" in the physical sense of the word. The electronic module is fed "X" information...if certain parameters are breached the motor may abort full speed spin. This could be because of an unbalanced load (such as washing a single heavy item), a defective motor, too many clothes crammed in the machine (overloading), a pump/blockage issue, or defective pcb. The tacho generator supplies the pcb with a reference voltage which in turn is used to regulate motor speed. Normally when the tacho fails completely the motor would run seriously overspeed (perhaps to the point of destruction). You don't appear to have this condition. Which points to A: a defective drive motor, B: unbalanced load, C: a pump/blockage issue, or D: a defective pcb.
Check that the brushes are fitted correctly. Heavy sparking around the commutator usually signals a defective drive motor