Potscrubber III?

[Chetlaham]

@marky_mark: spot on! That would be my theory as well.

I'd take the current draw during or right after the main wash fill has ended to take the motor into account, then the reading several minutes into the main-wash to get both of the motor and heater running together. Subtract the motor from that number and you'll get the heater wattage. Watts setting (not VA) can also get the job done.

 

[panthera]

Darlings, we're overthinking this

Run the damn thing on main wash 10 minutes. Unplug or trip circuit breaker.
Measure resistance at heating element. Plug into Ohm's law calculator, assume 120 volts.
Done.
It's a purely resistive load for goodness sake, no power factor to correct for, VA for an AC resistive load is Watts.
Goodness!

 

[Chetlaham]

Resistance varies with temperature. A heating element being cooled by water will have a lower resistance than one in open air.

 

[panthera]

Yes, resistance varies by temperature.

This is why I said to run the dratted thing for ten minutes, turn off the power (circuit breaker/ pull plug) and then measure the resistance at the heating element.

Realistically, it will be about as high as it's going to go, producing the lowest Watt rating.

I do think we sometimes get carried away by details which are of no consequence whatsoever.

I also think it's possible that the thermal delay on this dishwasher may not be working or only working intermittently.

Possible, not necessarily so.

 

 

[panthera]

Float Switches, Flooding, Failed Timers

Failed float switches are, indeed rare. Failed timers, however, even this improved version, are not. Especially not on an appliance coming up on 40 years old. Considering that that float switch is the only thing between a flooded house and a timer stuck on fill, I would err on the side of replace the silly little thing with the fill valve.

 

[eronie]

A clamp on watt meter will give an instant answer!

 

[combo52]

GE Pots-Scrubber 3

Resistance does vary temperature a tiny bit but I do not believe these DWs had the newer variable resistance heating elements like WP has been using for the past decade or so where they go from 400-800 watts depending whether being wet or dry [ WP has a very high failure rate with these new heating elements ] Heating elements almost never failed in DWs now it is a really common repair.

 

I don't believe that these GE DWs had any thermal hold, it was pretty much done on a time bassists, this has always been one of the things I do not like about GE DWs they either don't add the heat needed or if someone has really hot water they add heat anyway and destroy the dishes and DW.

 

I would never replace the original timer or float switch on an older DW if it showed no sign of failure, replacement parts like FSs and timers are no longer being made for these DWs and the quality of replacement parts are not as good as the original parts that were used to build the DW.

 

John L.

 

[cam2s]

Amperage draw

Running a full cycle now...power scrub selected again. On initial start up with motor it drew 1.8 amps, kicked up to 1.9 amps when the fill solonoid energized, pushed to about 2 amps as the motor picked up load and then settled at about 1.9 amps at full load with the fill solenoid off. The drain cycle showed about 2.5 amps. Heater did not not turn until the main wash segment, it’s settled in on about 5.25 amps.

The next load of dishes I’m going to get the reverse rack portable out and test it. The GE shaded pole motor has been accused of being inefficient but draws less than what the RR is rated and the new psc motor draws way less.

I’m having far to much fun here being geeky!

 

[panthera]

shaded pole motor

This motor is a single phase, induction motor.

It's advantage is, of course, that, as long as the bearings last, the motor will run forever with no other service ever required.

The shaded pole runs at roughly 20% efficiency (dear anal retentives, we all know you're just itching to put in 19.0000000000000000000000000000000000000000000000000000000000000000000000000000000000009%. Restrain yourselves, do, please.)

PSC motors run at 45% efficiency (dear anal retentives, give it a rest. It's close enough.)

 

So, no, efficiency is not a shaded pole motor's strength. On the other hand, unlimited life span, total reliability and super-simple, super-cheap manufacture are variables which GE probably valued highly.

 

Personally, I like to think the extra heat contributes to the cleaning. That is, after all what the other 80% of the power going into the motor which is not operative force comes to be.