F&P 703, grinding sounds and electrical burnt smell

[admin]

Hi all, first post…
I have a F&P 703 that is making loud grinding sounds when agitating or spinning, and produces a burnt electrics smell. I have already done the following:

Complete strip and full clean of inner and outer bowls, agitator, coupling cog under agitator, pump, water collection area etc.
Replace bearings, making sure they are seated correctly and square.
Checked pump function, all fine.
Checked no contact by rotor on stator, and rotor inner clean and debris free.
Checked water pressure/level tube is clear.
Checked for correct function of solenoids, all fine.
No water damage to module or touch controller.
No water damage to pump.
No water damage to rotor or stator.
No apparent damage to RPS.
No damage to wiring or OOB switch.

The weird thing is that the drive shaft spins fairly freely in the bearings right up until I attach the rotor, whereupon the grinding starts of very lightly quietly and hard to feel, but it increases in sound and feel as I tighten up the rotor nut. With the rotor fully installed there is a very obvious “toothed” feel to the rotation, but I cannot see any wear marks etc on rotor or stator.

I have some spare parts including a spare rotor and stator, but from memory if I change the rotor and stator I need to “tell” the module that it’s driving a new motor. I can’t remember the button sequence, can someone help with this please?

Any assistance or ideas would be greatly appreciated.

Thanks, Will (Melb, Aust)

[DaveP68]

Re: F&P 703, grinding sounds and electrical burnt smell

Hi

The 2 electrical parts that generally cause a burnt smell are the pump coil or the stator windings.

You need to check the resistance of each. For the pump it should be no less than 33 ohms at the terminals (pump cold). The stator requires 2 separate measurements. 1st is resistance between phases and should be no less than 12.2 ohms (measure directly on stator terminals). 2nd requires the removal of the star connection point and insulation resistance measurement of >5 Meg ohms between phases.

Question for you is had the bearing failed before you replaced it? Reason I ask is there is a lip half way down the shaft that can wear if the bearing fails. Another factor that can cause problems is the floating clutch splines. The driven spline has a metal washer to allow a fine clearance. If worn or missing the inner bowl will rub against the bottom of the outer bowl.

If you are going to change the stator and/or rotor on the same machine there is no need to carry out a resize on the motor controller. Motor is universal unit used on all 3 size machines made by F&P. The resize setting is only required if you put a replacement motor controller from a different size machine into your 7kg (703) machine.

Hope the above has been of some help to you.

[admin]

Thanks for the reply Dave. I replaced the stator and rotor last night with a spare that I had, and the machine is working fine. The thing that was worrying me was the notchiness of the rotor when turned directly by hand. However, I decided to give it a go and it’s all working well. I believe that the electrical smell was the stator or RPS, as when I pulled the RPS off, there was some burning on the plastic pin that goes through the stator windings.

Re the bearings, yes they were definitely badly worn, but had not failed completely. The metal washer on the clutch drive gear is partly worn but appears to have plenty of wear left.

So now I have a spare motor, might have to see if I can convert it into a generator…

Thanks a lot for the reply.

[Author]

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