Siemens WM - New Motor - Faulty Spin Behaviour

[kenmg]

Have a siemens washing machine, front load.
(Model - Siwamat Plus 3381 - FD7106) Stopped spinning.

The brushes had worn to the wire. One stiff bearing too.
Replaced brushes. No change (still no spin).

Got reconditioned motor which has 8 pins rather than 6 on original.

6 pin connector from machine fits into centre 6 pins on motor.

New motor also has additional component lying close to armature in body of motor. Looks like additional overload protection module?

Asked about pin mismatch and was told should work.

Pin 1 - connects to both sides of additional module
Pins 2,3 - 2.5ohms
Pins 4,5 - 3.1ohms
Pins 6,7 - 16.1ohms
Pin 7 - ?

(by the way - the old motor readings now (after new brushes) much the same as above except pins 4&5 read ~2000ohms)

Now...When running through program, machine doesn't 'get into' proper spinning action.
Will spin drum about 1 single rotation,and then give up - intermittently, as it moves through cycle.

And when on final spin part of cycle, attempts spin but drum knocks about, and then the attempt stops.

Any experience of this, or any ideas as to what's happening??

 

[zipper]

Post the "E number" on the door sticker...model & FD numbers don't help a great deal.

 

[Leccy758]

The overload protection thermal fuse should be linked across two seperate pins as it complete a circuit that can either go back to the motor control board or be linked through in the motor connection plug 'usually a loop of wire going between two pins).

Not normally advisable to change the type of motor for a different one as some have different properties especially on the tacho so can give duff readings to the control circuit.

 

[kenmg]

E number : WH33810ID/08
Motor ID : 3047583AA1

New motor ID is same as original, may be from earlier or later machine.

New motor has 8 pins, but..The additional thermal fuse(?) is on pin 1 and thus unused when connected in this machine.

Certainly strange that one pin connected to both sides of 'fuse' but maybe it gives some useful data when armature spinning (or not spinning) close by.The other pins (2-7) are wired the same as the original motor.

This motor has a moulded plastic & metal 'cage' for the brushes, and for routing connector contacts to the tacho (ring built into head?) and field coil.Concerning the tacho -

When the machine is being assembled, would the other electronics (controller only?) be 'tuned' to the individual motor (including it's tacho)?

On further investigation - problem with old motor (apart from tight bearing) seems to be with the brushes I fitted. To avoid having to buy full manufacturer brush 'cage', I called into local repair shop and got spurious brushes. Wire would have fouled spring, so they had to be removed.

Person there said contact with 'brush run' may give adequate contact. I didn't check contact quality when I had them fitted. They were giving the almost open reading on pins 4&5 when I tried. At best, they gave about 8ohm. I could refit wire in some way, or buy new 6-contact cage.

Overload fuse on old motor seems OK - presumably the motor literally 'ground' to a halt. possibly messed something else up while it was doing it..
Basically what I may have is -NEW MOTOR - basically nothing wrong with it, 'identical (enough) to original' (but machine not calibrated to it?).

ORIGINAL MOTOR - bearing on way out, brushes as fitted need wire fitted OR buy new cage OR swop in cage from new motor.Can't see how to get good bearing off armature in new motor.
(pulley in way - would pulley be fitted to spindle by cooling? - heat to get off?)

One possibility -USE OLD MOTOR
Swop in brush cage from new motor OR re-fit wires to brushes.
Clean & lubricate bearing, to improve things a bit, to test.

If it works, try new armature (with good bearing) in this old motor, see if still ok.OR swop bearing if possible.

How does that sound?

 

[zipper]

I got a headache reading your last post
But I got the bulk of it (I think). The original motor configuration is 6 pins numbered 2 - 7:
2 & 3 field windings (with thermal overload connected is series).
4 & 5 armature.
6 & 7 tachogenerator.
Approx resistances: 2 & 3= 2.6 ohms - 4 & 5= 3.5 ohms - 6 & 7= 18 ohms. If you got 2k ohms between 4 & 5 on your original motor it was probably only because of bad brush contact. You could swap the brush assy over (if it fits) but that still leaves you with a bearing problem. If the DE bearing is bad then the pulley has to be removed (with a bearing puller) to change it. The NDE bearing is easy to change. I wouldn't go swapping around armatures, tachos, or field windings.

 

[Leccy758]

Just a little question

You posted the wire would have fouled the spring so they had to be cut off ???

If you mean the braided tails then they have to be fitted to make a good contact electrically. I have replaced loads of 'Bosch' motor brushes with pattern brushes 'occasionally having to do some trimming down and or soldering of the tails onto the old connector and reusing the old springs'

The brush holders are prone to clogging with carbon dust as well especially recently changed ones so they should be cleaned out to allow the brushes to move freely.