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1946 Kohler 1A21

Frank DeWitt

Subscriber
Last Subscription Date
12/17/2019
I appreciate he suggestion, but it turns out I was putting the cart in front of the horse. I assumed that because the battery voltage for the unit is 24 volts that the relay would be 24 volts. This afternoon I measured the voltage on the terminal that energizes the relay and found it to be 60 volts. This voltage comes from the generator as it powers up. Upon looking further in the manual it says that the voltage has to be a minimum of 50 volts to energize the relay. I guess I am back to square one trying to find a compatible relay, or a way to use a 24 volt with some type of resistor to cut the voltage and not burn up a new relay. I don't imagine that a 110 volt relay would energize enough to be usable.
I think you found the purpose of JR. BTW did you check the voltage to the coil when you manually hold the relay in? That is the voltage it will see long term. It may be lower then 60. You would still need a resistor so it doesn’t pull in until 50 volts.
 

Frank DeWitt

Subscriber
Last Subscription Date
12/17/2019
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Is this the diagram everyone is working from? If anyone has a different or better diagram I would like to see it. I am used to schematics that are not as pictorial where the layout is driven more by the circuit function.
 

Vanman

Subscriber
Last Subscription Date
06/10/2020
Yep, that’s it. It’s a simple enough circuit that the layout of the schematic is not too much of a hindrance, just takes a bit longer to trace out each function. Once you’re familiar with it, it’s logic and elegance becomes clear.

Note that the generator relay coil does not receive any power during cranking, as it is locked out by an auxiliary contact on the cranking relay.

The cranking relay will not drop out until the engine fires and gains enough speed to operate the governor switch.

Thus the generator relay cannot pull in until the engine is at least running that fast.

The resistor in series with the generator relay coil ensures that the engine gets closer to running speed before the relay pulls in and the load is connected.

Note that you will be reading full exciter voltage across the generator relay coil while the set is running if that coil has failed open. There will be no voltage drop across that resistor without the load of the generator relay coil across it.

Keith
 

Turbo

Subscriber
Last Subscription Date
06/06/2020
It was 45 degrees in Minnesota today and I had a couple hours to play so I was able to install a new 300 ohm resistor that I found on eBay. It fits perfect and the generator now works correctly. Woo hoo!!;) Thanks for all the help guys!! I will get a video of it in the next couple days. I also rebuilt the fuel pump and mounted a tank underneath.
 

Attachments

Kohlerallen

Registered
I had some free time last night to tinker with my generator. I removed the control box and put it on my bench. I completely disassembled, cleaned and tested the components. I found my problem. In the manual this is called a "fixed resistor". It is 320 ohms and according to the diagram sends power to the generating relay after the crank relay drops out. This resistor is totally shot, I took the resistor out of my parts control panel and it too is bad. I had a 500 ohm resistor laying around and tried it, but it must be too much because it does not work. I can jump it with a test lead and the coil pulls in and the gen puts out 120V. Is there a modern resistor that anyone can recommend? I haven't looked online yet, thought I would start here. Thanks
You mentioned a parts control panel- if you have the center relay in that panel and it may be an extra for you would you be willing to sell it?
 

Turbo

Subscriber
Last Subscription Date
06/06/2020
My parts panel looks like it was pulled from a swamp. Most parts are not usable. The center relay coil is bad. I can see broken copper sticking out. Sorry I can't help on that.
 

Turbo

Subscriber
Last Subscription Date
06/06/2020
Sorry for the long delay. I have been very busy with work lately but today I finally had some time to mess with my own junk. It is almost a finished product! A quick recap of my progress; I built a cart, installed a 1 gallon fuel tank underneath and plumbed up to a rebuilt fuel pump, diagnosed and repaired the electrical problem by installing a new 300 ohm resistor in front of the gen relay, built a mounting platform for the safety switch and receptacles, found a nice old Westinghouse safety switch and Leviton surface mount receptacles to install. Lastly, as I don't intend to lug around batteries because this thing starts very easily with the crank, I added a kill switch to the side of the control box. I removed the wire from the big relay on the LH side and tied it into a momentary switch that goes to frame ground. I am very happy with this project and it will serve my purpose very well as a power source for some antique washing machines at local shows.
 

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Frank DeWitt

Subscriber
Last Subscription Date
12/17/2019
Very well done, but part of the fun at shows is demonstrating the auto start. These generators are such low compression that almost any batteries will start it. I use two lawnmower batteries . I have tried a couple small gel cells and they worked.
 

Frank DeWitt

Subscriber
Last Subscription Date
12/17/2019
I haven’t tried it but I bet a 24 volt lithium drill battery would start the generator. You would need to disable charging either internally or with a external relay.
 

Turbo

Subscriber
Last Subscription Date
06/06/2020
Very well done, but part of the fun at shows is demonstrating the auto start. These generators are such low compression that almost any batteries will start it. I use two lawnmower batteries . I have tried a couple small gel cells and they worked.
You are right Frank, Just flipping the lever and having it start would be pretty cool! :cool: I will play with that at some point but it starts so easy with the crank that I don't really want to mess with batteries. Heck, I don't even like hit and miss engines without magnetos for this same reason!! LOL
 

Kohlerallen

Registered
I finally had a day off today and had some time to play. Here is a short video of this generator running my 1921 Maytag model 41 washing machine. It works very well and will make a very nice display if we have any shows this summer.

What did you take your video with? I tried taking a video of my 1A21 to show progress but the forum would not accept the video as it was mn4 format.
 

Turbo

Subscriber
Last Subscription Date
06/06/2020
I go to YouTube, find my video, copy the address in the bar then paste the link into my thread response. Pretty simple
 

Joec3113

Registered
Nice unit! Probably a dumb question but to get the oil filter out you undo the one center nut then the top cover just spins off? Mine is pretty rusted and I didnt want to muscle it off and break it. Any luck finding a source for replacement oil filter?
 
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