Calling Stevet calling stevet KDP-20 acting up!

[jetcone]

Hey Stevet: almost done restoring my KDP-20 but I have found a problem with the bimetal motor on the pre-wash door. It doesn't open. I have removed the doors cleaned the shafts and installed new o-rings. The wash door SNAPS open. I notice the pre-wash door is wired through the rinse aid dispenser and the wash door is not.
How do these bimetal things work, I tried removing it and applying power directly to the bimetal and it shorted the circuit breaker.
signed-
Confused in Boston.

jon

 

[tomturbomatic]

Calling Dr. Bombay. Calling Dr. Bombay. Please come in. We need you right away.

 

[jetcone]

Bump

bump

 

[jetcone]

double bump

bump bump

 

[appnut]

Calling Dr. Bombay. Calling Dr. Bombay. Please come in. We n

Maybe Dr. Bombay isn't tuned in to listen for your page since this is a KA dishwasher and all Samantha had were Frigidaire and Maytag dishwashers.

 

[jetcone]

LOL!

Well it seems to be working now and since its almost a Solid State part I will declare the DW done and ready for service. In it goes next week! It sure uses a LOT of water--YAY!

I bet the timer just needed to be run a few times after sitting an Age.

So Hmmph! to Dr. Bombay!!

jet

 

[fnelson487]

Jet

Let have pictures!

 

Fred

 

[jetcone]

Will do Fred

It goes into service this week!

 

[stevet]

Close but no cigar!

Jon,

The bi-metal springs on the detergent dispenser are usually trouble free unless they get rusty or the wires corrode off of them.

They do not work by energizing them with 120 volts as you saw.You tripped the breaker because you created a dead short circuit.

They work by passing a current THROUGH them and the heat that created through the bi-metal causes it to bend and then it releases the detergent cup clip and the door swings open.

The rinse agent dispenser works the same way on your machine only it opens the plunger on the dispenser and lets the rinse agent drip out when the bi metal spring heats up.

The bi metals are wired into the circuit by switching the pump motor current thru the bi metal for the specific cup either DC1 or DC2 The prewash cup should be DC1 and the main wash cup should be DC2.This occurs for only a short period of time during the cycle and then the timer switches the motor back to a direct connection and the bi-metals are allowed to cool and return to their normal shape and positions.

You will see this on your wiring diagram. On the later series, they used the motor current for one door and the sump heater current to open the second door. The rinse aid still used the motor current.

Just look at it carefully and you will see how it works.

Hope this helps.
Steve

 

[jetcone]

Ahh so

the bimetals are switched into series? with the motor windings or parallel? with the windings?

Alas all I have is the visual schematic on the door, no actual wiring diagrams. It shows the wiring going to the components but not the actual diagram.

But it did work yesterday.

 

[jetcone]

bump

bump

 

[stevet]

Series...

Yes in series, Jon. So that the current flowing thru them will bend the bimetal to unlock the door. Doesnt last too long..maybe one timer increment. The cycle chart may tell more but it doesn't reflect how it is wired. The Door schematic will show the connections but won't say when it happens either.

 

[bajaespuma]

Possible "Blond" question:

What's the significance of "bump"?

 

 

 

[tomturbomatic]

Adding a posting moves (bumps) the thread back up to the top of the pile so it is more easily seen.

 

[jetcone]

Thanks Stevet

It seems to be working great now. Just needed a few runs I suppose. The metal strip is still very shiny.