KitchenAid K5-A Retrofit Using WPW10325124 Control Board

[bouxboux]

Hi all - n00b here - my apologies in advance for any formatting/policy gaffs.

I'm attempting to convert a standard KitchenAid K5-A to a Solid State using a WPW10325124 phase control board (see link below).

https://www.partselect.ca/PS11752886-Whirlpool-WPW10325124-Phase-Control-Board.htm

I'm here because I found this thread:

Help identifying suitable replacement resistor. Kitchenaid K45 Stand Mixer
https://www.eevblog.com/forum/repair/help-identifying-suitable-replacement-resistor-kitchenaid-k45-stand-mixer/

... specifically, the last post states:

"You can retro fit a phase board to the old K45 mixers without needing to change anything else in the mixer. This video (https://youtu.be /j6Y3QpW1TAY) suggests you need to change the speed control plate, back bearing housing and speed control linkage, this is incorrect)."

Does anyone know how to match the wire colors on the phase board to the existing mixer wires? I'd play with it, but don't want to damage the new phase board*. I've searched on this nine ways to Sunday and can't find any completed docs/pics on how this is done, or the color codes of the PCB wires. Any help is appreciated.

* I'm thinking the R/W goes to the Black on the mixer, the Red to Red, the Blue to Yellow and Black to Ground?

[floobydust]

Welcome n00b 

I did find a Kitchenaid mixer service manual with schematic.
It seems to have a "control plate" with mechanical govenor switches to give speed regulation and multiple speed options. I am speculating based on the wiring diagram.

So mechanical speed-feedback comes from the control plate/switch, which toggles the two speed-input wires of the phase control board, giving at least four different speeds:
1. nothing connected to blue and white/red for lowest speed.
2. Or Short white/red to red for speed A
3. Or short white/red to blue for speed B
4. Or short red to blue for highest speed.

Red still always goes to the (motor load) field winding.

You can try run it on a workbench using a lightbulb in place of the motor.
Again, I am speculating without details of the mysterious control plate's switches.

Whirlpool W10325124 Control
Red - connects to Control Plate, then thru to field winding (red)
Black - connects to Control Plate, then thru to Neutral (white)

White/red stripe - connects to Control Plate, speed select A.
Blue - connects to Control Plate, speed select B.

[bouxboux]

Thank you for your thoughtful post and schematic. I was able to run the mixer with the PCB for about 15 minutes yesterday before it crapped out. The mixer now runs at full speed only, indicative of a bad PCB.

At first I combined the Blue/Black/Yellow/White wires all together (like the original wiring of the resistor/capacitor - otherwise, I combined Red/Red and R/W with the Black wire in the middle of the speed control board), but the contacts on the speed control board were still sparking. So I separated into Blue/Yellow and Black/White ... the sparking stopped but the mixer was running choppy at slow/mid speed. I applied my finger to the planetary gear to create about the same resistance of a stiff pizza dough and it smoothed out the choppiness, but then crapped out after a few 10 seconds. I was able to 'jump' it a few times by combining all 4 wires again and then separating them once the mixer started, but then the PCB just quit and mixer just went into full speed.

I don't know if my initial wiring caused the damage and the PCB limped along until I created resistance - or - if the mixer needs a new speed control board (SCB) to match the PCB? I also don't know how much time and resources I want to throw at this. I was hoping this would be a relatively cheap and easy fix for this old workhorse. 

[floobydust]

The tough part here is keeping speed regulation.
The centrifugal switches - the old mixer just has the switches in series with the motor, so lots of sparks and high current getting switched to maintain speed?

Sparks across the contacts would make voltage spikes that beat up the triac, it sounds like it failed and is shorted.
You can replace it, not too difficult, and try again

The new mixers, the centrifugal switches are supposed to toggle between different speed settings on the phase-control board.

I'd have to see good pictures to understand the (yellow?) wiring and switch plate.

Otherwise, a $6 eBay "4000W speed controller" which just acts like a big light dimmer would only give variable speed but no speed regulation wuth load. I don't think it would be any fun mixing thick dough.