I have a friend who has a 46 or 47 d model scraper with electric over cable controls. it seems to lose all electric power to everything after alittle bit of time working like after its good and warm. is there anyone out there that knows about these machines or a web cite I could contact. thanks for your time. ( god bless cushion hitches)
It's been years since I've heard of anyone trying to run one of those. The two things I remember was that the rectifiers would burn the paint off of fins indicating they were probably going bad. As I recall they changed AC to DC for the field excitation in the generator and going out to the motors. The other issue was the insulation going bad in the generator and not putting out much power when they got hot. I had a warehouse full of parts so when the one we had left had a problem we just swapped out generators and rectifiers. There are few people here that have more experience with them and maybe they can tell how to check things out.
thanks I haven't got close enough to the machine yet its on a big ranch they do a lot of pond work with the scraper and a 17a d7 im going to help them this spring when things dry out a bit. he said it runs great till it warms up then nothing. I welcome any help I can get as most of the mechanics are long gone
Wow, Tournapull questions!!!! The only one I remember was the switches on the dsh panel for steering and when one went bad or stuck, it was an "E" ticket ride for the operator. That and it seemed like they always broke down in a mud hole.
So does it lose power suddenly? or gradually? Its been 30 years since I've worked on an all electric machine. This might jog my 2 brain cells a bit. Plus I'll do some digging... may still have a manual for them.
well here's the deal iv been a operator since 76 this machines on a ranch in Idaho the owner is a friend who's good at punching cows so I haven't got close to the machine yet but I think he said it loses power suddenly. in my case Ive never done anything else but run equipment my whole life im still a kid when I see some. but its the first time around electric switches on a machine that old. he has some manuals. so as soon as it drys out a bit ill check it out(hes has a lot of ponds to bulid yet the push cat is a 17a d7
A sudden loss off electrical power is usually a generator rotor issue. Best way to check is with a voltmeter and ammeter on the field leads. If the field voltage drops and the amps don't go up, Its usually a rectifier. if the amps spike when the power drops its more than likely a rotor with a centrifugal short. I mostly work with Wabco scrapers here and there anymore and they are a bunch simpler to diagnose then the old all electric machines.
this machine will run great,everthing works steering,can controls then as soon as warms up nothing
One other thing to check would be the rectifier cooling system. I believe a machine of that age used oil cooled rectifiers and if the oil is low they will heat up and resistance will increase. Should be a small "tank" on the left side in front of the cab mount with a bunch of wires connected to it. The old manuals said to use "transformer oil". I never had to procure any, so I have no idea where to get it.
iv been emailing my friend he said he replaced the rectifiers with diodes and they are a oil bath type
All the rectifiers we had were air cooled. I had heard of the change to diodes but never saw how that was done. Good information that I hope to never have to use