Servis washer not spinning without a load

[bobokines]

I seem to recall seeing somewhere that some Servis machines will not spin without a load. Does anyone have any knowledge of this? (and why it should happen)

I had a washer dryer today that would not spin after I had replaced the module. Something in the back of my mind told me to put some towels in and off it went!

Bob

[admin]

Re: Servis washer not spinning without a load

Correct Bob,
they have an electronic load detection that monitors the current drawn by the motor on lifting the load. “out of balance”.

The neoprene belts (fawn coloured) do stretch and the replacement multi v is a 1230 j5 size in rubber, part number is on the old belt, you receive a rubber one nowadays.

The modules affected are all DMPU ones along with DMPDC and all fitted to M6135’s.

The common fault is that it just won’t kick into spin, just does the “distribute” cycle. The cure can be module or belt.

Kevin

[bobokines]

Re: Servis washer not spinning without a load

Sorry, should have mentioned that this is an induction motor model with a 22mfd Capacitor. The belt on these is a simple V belt.

I might be missing something here but a well balanced load (or no load) will have a regular motor current and I can’t see the point of not spinning it.

Bob

[Dave_Conway]

Re: Servis washer not spinning without a load

Nor can I Bob to be honest.

I always thought the “out of balance” was detected by the PCB sensing the pulses from the tacho not giving a constant or gradualy increased voltage as the motor picks up speed 😕

An empty load would not produce any fluctuation in the tacho output therefore it should spin….

Mind you, it’s a minor miracle to get a Servis to do anything 😆

Dave.

[admin]

Re: Servis washer not spinning without a load

Sorry, but its the opposite…

It needs to detect “Weight” by measuring current draw, to iniatiate spin, no weight no spin. Put in a single item such as a shirt, won’t spin!

Then factor in the piano wire tension the belt has to be under to transmit the torque to the tacho, no wonder the bearings fail. How many Servis have you been to where the rear bearing falls in and out without being an interference fit????? Think about it?

Kevin

[Dave_Conway]

Re: Servis washer not spinning without a load

You learn something every day :lesson:

Cheers for the explanation Kevin 🙂

Dave.

[robbra]

Re: Servis washer not spinning without a load

Worked for SUK from 1996 when they started their own servicing and now sub via GB Dars.All machines after the 7 tag module should spin without a load as long as the belt is tensioned. The problem arises when a small load drops during distribute and causes the motor to jerk. It will then keep distributing till the load is even but it if it cant even it out it won’t. There are also problems with pressure switches and pressure pots but the test is…If it won’t spin empty and the belt is taught the problem is elsewhere.
Rob

[Penguin45]

Re: Servis washer not spinning without a load

Earth leakage on the heater (no matter how slight) throws the board off as well.

Chris.

[bobokines]

Re: Servis washer not spinning without a load

Thanks Chris. I know that an earth problem on the heater can cause no spin on some Hotpoint machines (this is because it puts an earth return on the pressure switch which the module thinks is a water level) but I didn’t realise is would make a difference on a Servis.

I always megger a machine before starting work anyway but the heater is often double pole switched and cant be tested from the plug top anyway.

By the way, on a Hotpoint it’s always best to meggar the heater from the heavy wire on the pressure switch.

Back to the out of balance detection; in my experience, most machines test out of balance by detecting varying armature current during the distribution phase, not, as most would expect, from the tacho pulses. The only exception to this that I know is the early Hotpoint MicroProfile range (9560 etc) that used an analogue motor with a digital control.

Bob

[Author]

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