Nice restore
Ive never used a pot scrubber , does that are nutate as well as rotate?
Ive never used a pot scrubber , does that are nutate as well as rotate?
Potscrubber III?
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Yes Jon, it nutates and rotates. It's what is why it's called multi-orbit wash arm.
Uncle Owl Face would be proud of you
I'm not an engineer and high-school geometry was a very long time ago, but, yes, I believe the wash arm's patterns are nutations of an orbit. Euler's second law? Way too long ago.
Anyway, there were three wash arms from the post PotscrubberII era. This one, on the higher-end machines caused Consumer Reports to dethrone KA and announce (with tremendous reluctance, they were bought and sold to KA) that this dishwasher was better at cleaning. Much better.
A simple mechanism (looks like a cam to me, but I'm not an engineer) throws the arm out and then draws it back in during it's rotation. It isn't truly random, but it does make sure that even the further most corners of the top rack get thorough coverage.
A second variation also uses whirligigs on top of a regular arm (Frigidaire does that on some, still, today) and they were absolutely the most horrible, terrible, clog-prone, stupid, worthless trash GE ever put on the market, doing great harm to my opinion of them.
The third variation, the one still in use on the last of the Potscrubbers (the ones you get from Home Depot for 250-350$), doesn't nutate, it just rotates and sprays water through big holes. Does a pretty good job, given enough water, to be honest.
One must never upset the KA folks (we've had several ourselves and yes, they're wonderful, the very best, truly the holy grail, blah, blah, blah), but this design really would have made the 18" dishwashers clean well in the corners and it runs rings around everything else when you're dealing with truly dirty dishes.
I'm not an engineer and high-school geometry was a very long time ago, but, yes, I believe the wash arm's patterns are nutations of an orbit. Euler's second law? Way too long ago.
Anyway, there were three wash arms from the post PotscrubberII era. This one, on the higher-end machines caused Consumer Reports to dethrone KA and announce (with tremendous reluctance, they were bought and sold to KA) that this dishwasher was better at cleaning. Much better.
A simple mechanism (looks like a cam to me, but I'm not an engineer) throws the arm out and then draws it back in during it's rotation. It isn't truly random, but it does make sure that even the further most corners of the top rack get thorough coverage.
A second variation also uses whirligigs on top of a regular arm (Frigidaire does that on some, still, today) and they were absolutely the most horrible, terrible, clog-prone, stupid, worthless trash GE ever put on the market, doing great harm to my opinion of them.
The third variation, the one still in use on the last of the Potscrubbers (the ones you get from Home Depot for 250-350$), doesn't nutate, it just rotates and sprays water through big holes. Does a pretty good job, given enough water, to be honest.
One must never upset the KA folks (we've had several ourselves and yes, they're wonderful, the very best, truly the holy grail, blah, blah, blah), but this design really would have made the 18" dishwashers clean well in the corners and it runs rings around everything else when you're dealing with truly dirty dishes.
The multi orbit works kinda like a kitchen aid stand mixer, it rotated off center so it makes two circles as it goes around. Every picture below is one full turn, hopefully you can see how it’s in a different place everyone. Also you can see the track and pinion gear that the eccentric orbit runs on.
Yup,
Nothing cleans remotely as well. Good illustration.
Nothing cleans remotely as well. Good illustration.
What a great job you're doing on this nice machine, Cameron! I've been following this thread with interest as I have a GSD1250 that I intend to fix up myself. This thread has been really interesting and useful!
One thing I don't get is the power of the heater. When I read reply #13 (photo #14) a few weeks ago, I was surprised to see the heater listed as 115V 3A. That would make it just 345 W. I remember thinking that this would have to be the lowest-power heater I have ever seen in a dishwasher. But in reply #37 panthera mentions that you have the 900 W heater. So how can we tell? Does this mean the heater has been replaced at some point, or the label isn't original to this machine? I did think the heater was pretty big -- I don't think mine has a heater that big.
Great thread of an an excellent restoration.
Mark
One thing I don't get is the power of the heater. When I read reply #13 (photo #14) a few weeks ago, I was surprised to see the heater listed as 115V 3A. That would make it just 345 W. I remember thinking that this would have to be the lowest-power heater I have ever seen in a dishwasher. But in reply #37 panthera mentions that you have the 900 W heater. So how can we tell? Does this mean the heater has been replaced at some point, or the label isn't original to this machine? I did think the heater was pretty big -- I don't think mine has a heater that big.
Great thread of an an excellent restoration.
Mark
I decided to do a little experiment to see how much the Calrod can raise the temperature of the wash water. The incoming hot water at the tap was measured at 115 degrees. I used the power scrub cycle with the extended main wash. The sequence leading up the main wash is pre wash, pre rinse, pre rinse, main wash. The temperature at the beginning of the main wash was measured at 109 degrees, the temperature at the end of the main wash was measured at 120 degrees. The main wash is not quite 30 minutes long.
It does call for 140 water, I was hoping to see the water get a little warmer by the end of the wash but it is what it is. I usually used the power scrub cycle in my Bosch which provided a 165 Degree wash. I’m learning to use the super racks, the upper rack is very spacious.
It does call for 140 water, I was hoping to see the water get a little warmer by the end of the wash but it is what it is. I usually used the power scrub cycle in my Bosch which provided a 165 Degree wash. I’m learning to use the super racks, the upper rack is very spacious.
Temp
The GE manuals that I've read from the 80s mention that every time the door is opened the water temperature is lowered.
The GE manuals that I've read from the 80s mention that every time the door is opened the water temperature is lowered.
Cameron, was this temperature test using Normal Wash or Power Scrub that had the main wash at only 30 minutes?
That's interesting. I don't know for how much of that main wash cycle it will have been heating the water, but that small temperature rise does seem to me to be consistent with a 3-Amp heater if it was heating for almost 30 minutes.
Without the extender I'm counting a 9 minute main wash. Assuming the extender prolongs the wash time by a factor of 3 that would be 27 minutes of main wash. 5 1/2 minute final rinse, with the extender about 16 1/2 minutes.
Considering your fills are over 2 gallons (more water to heat) I'd raise the temp on your water heater.
Considering your fills are over 2 gallons (more water to heat) I'd raise the temp on your water heater.
Pots-Scrubber 3 DW
The heating element in these DWs is only 400-500 watts, GE was very cautious because the plastic tub was still a fairly new concept in DWs
John L.
The heating element in these DWs is only 400-500 watts, GE was very cautious because the plastic tub was still a fairly new concept in DWs
John L.
Several potscrubber heating elements I have tested
Came in pretty close to 500 watts. I remember reading in an appliance for him sometime in the late 1980s that general electric had decided to de-rate the elements down to prevent damage to the plastic liner.
Given that this is a purely resistive load I think ohm's law will work quite well enough for it even though it is an AC measurement.
I'm getting pretty consistently 29.x-31.x Ohm's and at our 124VAC (that's pretty steady) we're around 500W.
Came in pretty close to 500 watts. I remember reading in an appliance for him sometime in the late 1980s that general electric had decided to de-rate the elements down to prevent damage to the plastic liner.
Given that this is a purely resistive load I think ohm's law will work quite well enough for it even though it is an AC measurement.
I'm getting pretty consistently 29.x-31.x Ohm's and at our 124VAC (that's pretty steady) we're around 500W.
GE Pots-Scrubber 3
Hi Mark, Reply #45, I had not noticed that 3 Amp draw on the name tag, We have almost the identical DW in our wall of DWs at the museum and ours lists the heater draw at 6 Amps, total draw at 9 Amps with the motor Amps being listed at 5 Amps, it does not add up, and on this DW the heater is listed at 3 Amps and the motor at 5 Amps yet again GE says this adds up to 7 Amps even though for nearly 1/2 the cycle both the motor and heater are both running together.
I think WE need to do some real testing.
Someone said something about inlet valves and float switches failing on US DWs.
Inlet valves will wear out-fail on almost all DWs if they last long enough otherwise between 5 and 20 + years.
Float Switches will NEVER fail in over 99% of DWs even if the DW lasts more than 30+ years, a FS is a safety overfill device on US DWs and even though it can cycle thousands of times without wear the great majority of DWs will never have the FS cycle even once in the operating life of the machine.
The only thing I have ever seen make a FS fail is if water leaks on it or into it long enough for it to corrode and fail.
John L.
Hi Mark, Reply #45, I had not noticed that 3 Amp draw on the name tag, We have almost the identical DW in our wall of DWs at the museum and ours lists the heater draw at 6 Amps, total draw at 9 Amps with the motor Amps being listed at 5 Amps, it does not add up, and on this DW the heater is listed at 3 Amps and the motor at 5 Amps yet again GE says this adds up to 7 Amps even though for nearly 1/2 the cycle both the motor and heater are both running together.
I think WE need to do some real testing.
Someone said something about inlet valves and float switches failing on US DWs.
Inlet valves will wear out-fail on almost all DWs if they last long enough otherwise between 5 and 20 + years.
Float Switches will NEVER fail in over 99% of DWs even if the DW lasts more than 30+ years, a FS is a safety overfill device on US DWs and even though it can cycle thousands of times without wear the great majority of DWs will never have the FS cycle even once in the operating life of the machine.
The only thing I have ever seen make a FS fail is if water leaks on it or into it long enough for it to corrode and fail.
John L.
Right, though Maytag cycled their float switches.
More testing...
Dropped down to Menards and purchased a Kill a Watt meter. Dropped the timer into the dry cycle with heated dry engaged and looked at the measurements...3.42 amps and 409 watts. Will have to take measurements next time I run it through a full cycle. In my opinion, since this was designed for 140 degree water the heater is more to maintain the temperature and not raise it.
Dropped down to Menards and purchased a Kill a Watt meter. Dropped the timer into the dry cycle with heated dry engaged and looked at the measurements...3.42 amps and 409 watts. Will have to take measurements next time I run it through a full cycle. In my opinion, since this was designed for 140 degree water the heater is more to maintain the temperature and not raise it.
Heater Power
Well that certainly clears that one up, Cameron! Very useful gadget indeed.
Once the dry cycle starts, I imagine the heater's power draw will begin to drop as it heats up and its resistance increases. Whereas when it's heating the water it should continue to keep drawing the higher amount.
Well that certainly clears that one up, Cameron! Very useful gadget indeed.
Once the dry cycle starts, I imagine the heater's power draw will begin to drop as it heats up and its resistance increases. Whereas when it's heating the water it should continue to keep drawing the higher amount.
@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.
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.
