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Mike, Been following this post for a while and my thoughts were also that a diode, both, or the cap had shorted. Since it had been charging for a while before turning on the disconnect, I'm betting the cap had heated up enough to short and when you finally closed the disconnect, a surge of current caused the diode/s to short. If you're going to buy an assembly from Jim, make sure you also buy a capacitor. I have been using solid state rectifiers to replace the diodes for a while now. They are much cheaper, don't have to remove the old diodes or heat sink, and have lasted MUCH longer. I haven't had a failure yet in the last 3 or 4 years. I have caps and rectifiers available, if you want to go that route. With it being a holiday weekend, might not be able to ship until tuesday. Say $25 plus shipping? All that is required to install the rectifier is a 1/4" hole (usually i drill between the two diodes and a bit higher), a bit of heat sink compound underneath it, and I'll send a #10 screw with it. I cut the transformer wires right at the diodes, crimp on a 1/4" female stab, and make a pigtail for the positive with a butt connector to tie to the tractor wire #30. The rectifiers are 10x quieter, also. Chad ------ Original message------ From: Briggs, Mi
chael Date: Fri, May 26, 2017 6:29 AM To: elec-trak cosmos phy tufts edu;noaddress drmm net; Cc: Subject:Re: (ET) Aaargghh!!!! On 25 May 2017 at 22:20, jlantonucci comcast net wrote:>> The charger is hard wired to the battery pack like Jim said. Turning off>> the power disconnect does not disconnect it>>David Roden wrote:>>Interesting. My HSM shows the E15 charger going through the main>disconnect. Dunno if my own E15 is wired that way thoug h.>>Also, Michael didn't get his fireworks until he engaged the disco.Exactly what I was thinking David. I'm 99% positive the main disconnect disconnects the positive side of the battery from the charger (on mine). The tractor won't charge with that disconnect open, and if it was permanently connected, there's no reason closing the disconnect should have caused the fireworks - since it shouldn't have changed anything. >The symptoms described suggest at least one shorted diode in the charger,>though since it apparently sent out smoke signals, it might be open now.Ok, new diodes it is then. I haven't touched the charger in over 10 years - where exactly are those diodes? I don't suppose anyone has some pictures or a video showing there they are. Most of my tractor is clean and shiny and looks practically new - but I can't say that about the charger. It looks every bit of its 40+ year age. >Looks like you'll have to remove the heatsink, press or hammer the old> diodes out, press in the new ones, and put it back. Jim mentions that the>aluminum may stretch so that the new diodes fit loosely, don't dissipate>heat well, and fail. He has a point.>>Jim conveniently offers a complete heatsink and diode assembly which is no>doubt the easy way to go. It is of course quite a bit more expensive.>>I tend to take such challenges as inspiration to my hacker side (the "make>it work" kind, not the "wreck someone's computer" kind). The nice thing>about this route is that if you can find diodes locally, you're back up and>running that much sooner.The hacker side of me also generally likes the challenge - but in this situation I just want to get it working again without too much time and frustration, since my plate is more than full (the whole reason for switching to a robotic mower - no time to mow, no time to fix tractor, etc.). So I like the quick and easy route - so I'll order the w hole heatsink assembly. I should probably also clean up the charger while I"m in there - it's kind of nasty. Thanks everyone!Mike_______________________________________________Elec-trak mailing listElec-trak cosmos phy.tufts.eduhttps://cosmos.phy.tufts.edu/mailman/listinfo/elec-trak |