Thanks for the comment. You're right about the Tournapull being cool. R G Letourneau is a hero of mine. You and I are lucky to have a few pieces of his equipment. Even though they're not as mainstream as Cat. He was so influential, I can see his ideas are going to come full circle. Hopefully I can rebuild some of those ideas in this old Tournapull. I can picture you and I thumb wrestling over who would get to push load with your D7, and who would get to drive the Tournapull. let me know when you finish your magic space aged Teleporter machine and we can have a play date in a big sandbox. Lol. Thanks for your support and enthusiasm it helps keep up the momentum.
The ONLY thing I can say is that I have seen MUCH more into one of those thinks than I ever thought I would. I can give you an A-PLUS for going as far as you have and seems like the old Mack motors ran the heater line to the back of the head. You might actually rig up a real heater off that line to keep from freezing to death and the block heater to the oil cooler on the other end is a fine idea. I'll try and give you all the moral support you can stand from an old broke down operator hillbilly. BLESSINGS to Yall!
For measuring high currents, get a clamp meter. You simply clip it over the wire you want to measure. Just make sure you get one that can measure both AC and DC. Uni-T make some decent, reasonably priced meters.
Im your neighbor in Alberta. I have had a pull scraper of Letourneau's for years. But to have one with the electric controls is so lucky. I would love to hear of any leads or knowledge on any thing Letourneau
Your transformer sends AC to the rectifier, which turns it into DC, which is (I guess) used to excite the field of the main motor? Also, best to use crimp terminals on anything with vibration in it like that - soldered joints won’t last. Plus that’s a terrible way to solder!
Thanks for the comments, I never thought about the vibration. I didn't want to use the blue and yellow automotive ones. But perhaps I can get some higher quality crimp ones. I'm all ears on a better way of soldering.
Not knowing what voltages you are dealing with the big wires will be the lower voltage high current and the high voltage will be opposite on the xfrmer You don't happen to know an elevator mechanic? They are well versed on cable machines that are AC/DC driven. Also are the terminals on the rectifier lid insulated?
Good to hear from you. Every time I read through the electrical service guide a few new details seem to make sense. I think your right about the transformers. This project feels a lot like I'm back in school. I study every night, lots of homework and the up coming final exams next spring.
It would not surprise me if the rectifier is dead. Those old selenium rectifiers don't age well. Does your manual specify the voltage and current that the rectifier needs to handle? I'm an electrical engineer and it would be easy enough for me to find a modern equivalent with that information.
Just did a bit of research on selenium rectifiers and the voltage rating is a non-issue. Going by the construction, what you have is unlikely to be rated for more than about 120V, more likely around 60V. Most modern 3 phase rectifiers are rated far higher than that (600V or more). That leaves the current. If your manual does not have a specification for that, my gut feeling would be to go overkill. A 110A rectifier should cost in the region of $80 CAD. Just looking at the wires, you aren't going to be pulling anything close to that current.
Good day. I hope you are well. In the latest video I put a wiring diagram at the end of the episode. Its pretty blury but I can tell you the line numbers. Check it out and let me know what you think.
@@PJTVenturesInc. I missed the schematic when I last watched that video. There are certainly some oddities in that wiring. Are you using 4x 6V batteries or 2x 12V batteries? Looking at the diagram, it appears that the oil pressure gauge runs off 6v, tapped off the first 6V battery in the string. If you are using 12V batteries you could have a problem getting the oil pressure gauge to work. The headlights appear to be wired in series using 12V bulbs. That means that if one bulb goes you lose both headlights! Anyway, getting back to the rectifiers, do you still have the ammeter on the dash? If so, what is the maximum current that it reads? That would give a good idea of the required current rating for the 24V main rectifier. It looks like the main rectifier is single phase. The constant voltage rectifier is a bit more of an unknown. The only thing we really know about it is that it's 3 phase. For this one we will have to just go well over size. Once I know the current for the main rectifier I'll sort out some part numbers for you.
Great to hear from you. No existing lights, and the oil pressure has been replaced with a mechanical one. The DC Volts gauge goes up to 60 volts. If you go to tractorparts.com site, this is where I got the pdf manual for the machine. It describes how the machine electrical system works pages 143 to 160. The PDF you want is www.tractorparts.com/PDFs/WABCO_MODEL_D_TRACTOR_SCRAPER_SERVICE.pdf
Should be worried about PCBs in the old transformer oil, which are extremely cancer causing. Take it seriously and dispose of it properly. You could probably replace that rectifier with a modern more efficient one, just bolted to a chunk of steel.
Thanks for the warning. I did keep the oil, grime and rags all separate and sealed. And I will look into where to dispose of it properly. I have reached out to find a different type of rectifier/system to up grade this one. The electrical side of the scraper is all new to me and I appreciate any help or tips I can get. All of the components are made by Letourneau so it might be a bit of a mixed bag to get it working again.
I’ll just be along for the ride as that electrical system is completely out of my wheelhouse. Best of luck with it but what a cool machine.
Thanks for the comment. You're right about the Tournapull being cool. R G Letourneau is a hero of mine. You and I are lucky to have a few pieces of his equipment. Even though they're not as mainstream as Cat. He was so influential, I can see his ideas are going to come full circle. Hopefully I can rebuild some of those ideas in this old Tournapull. I can picture you and I thumb wrestling over who would get to push load with your D7, and who would get to drive the Tournapull. let me know when you finish your magic space aged Teleporter machine and we can have a play date in a big sandbox. Lol. Thanks for your support and enthusiasm it helps keep up the momentum.
The ONLY thing I can say is that I have seen MUCH more into one of those thinks than I ever thought I would. I can give you an A-PLUS for going as far as you have and seems like the old Mack motors ran the heater line to the back of the head. You might actually rig up a real heater off that line to keep from freezing to death and the block heater to the oil cooler on the other end is a fine idea. I'll try and give you all the moral support you can stand from an old broke down operator hillbilly.
BLESSINGS to Yall!
Merry Christmas to you. Thanks fir the kind thoughtful words
@@PJTVenturesInc. Likewise you and yours!
The tool you require is a "Shunt Resistor". An appropriately sized shunt in combination with your DVM can measure very high currents.
Your hired. Lol. Thanks for the comment. I can only imagine how annoyed the electrical supply store will be with me. After this project is done.
They might be selling you stuff that hasn't moved stock in decades
I bet somewhere there's brand new old stock Letourneau rectifier plates sitting in a dusty old box. At least that's what I keep telling my self lol.
For measuring high currents, get a clamp meter. You simply clip it over the wire you want to measure. Just make sure you get one that can measure both AC and DC. Uni-T make some decent, reasonably priced meters.
Thanks for the tip. I do have a Fluke 323 clamp meter that i think will work.
great work on her. RG was so far ahead of his time. what part of Canada you from as i might know of some parts in Saskatchewan
Im your neighbor in Alberta. I have had a pull scraper of Letourneau's for years. But to have one with the electric controls is so lucky. I would love to hear of any leads or knowledge on any thing Letourneau
Your transformer sends AC to the rectifier, which turns it into DC, which is (I guess) used to excite the field of the main motor?
Also, best to use crimp terminals on anything with vibration in it like that - soldered joints won’t last. Plus that’s a terrible way to solder!
Thanks for the comments, I never thought about the vibration. I didn't want to use the blue and yellow automotive ones. But perhaps I can get some higher quality crimp ones.
I'm all ears on a better way of soldering.
Not knowing what voltages you are dealing with the big wires will be the lower voltage high current and the high voltage will be opposite on the xfrmer
You don't happen to know an elevator mechanic? They are well versed on cable machines that are AC/DC driven.
Also are the terminals on the rectifier lid insulated?
Good to hear from you. Every time I read through the electrical service guide a few new details seem to make sense. I think your right about the transformers. This project feels a lot like I'm back in school. I study every night, lots of homework and the up coming final exams next spring.
It would not surprise me if the rectifier is dead. Those old selenium rectifiers don't age well. Does your manual specify the voltage and current that the rectifier needs to handle? I'm an electrical engineer and it would be easy enough for me to find a modern equivalent with that information.
Just did a bit of research on selenium rectifiers and the voltage rating is a non-issue. Going by the construction, what you have is unlikely to be rated for more than about 120V, more likely around 60V. Most modern 3 phase rectifiers are rated far higher than that (600V or more). That leaves the current. If your manual does not have a specification for that, my gut feeling would be to go overkill. A 110A rectifier should cost in the region of $80 CAD. Just looking at the wires, you aren't going to be pulling anything close to that current.
Good day. I hope you are well. In the latest video I put a wiring diagram at the end of the episode. Its pretty blury but I can tell you the line numbers. Check it out and let me know what you think.
@@PJTVenturesInc. I missed the schematic when I last watched that video. There are certainly some oddities in that wiring. Are you using 4x 6V batteries or 2x 12V batteries? Looking at the diagram, it appears that the oil pressure gauge runs off 6v, tapped off the first 6V battery in the string. If you are using 12V batteries you could have a problem getting the oil pressure gauge to work.
The headlights appear to be wired in series using 12V bulbs. That means that if one bulb goes you lose both headlights!
Anyway, getting back to the rectifiers, do you still have the ammeter on the dash? If so, what is the maximum current that it reads? That would give a good idea of the required current rating for the 24V main rectifier. It looks like the main rectifier is single phase.
The constant voltage rectifier is a bit more of an unknown. The only thing we really know about it is that it's 3 phase. For this one we will have to just go well over size.
Once I know the current for the main rectifier I'll sort out some part numbers for you.
Great to hear from you. No existing lights, and the oil pressure has been replaced with a mechanical one. The DC Volts gauge goes up to 60 volts. If you go to tractorparts.com site, this is where I got the pdf manual for the machine. It describes how the machine electrical system works pages 143 to 160. The PDF you want is www.tractorparts.com/PDFs/WABCO_MODEL_D_TRACTOR_SCRAPER_SERVICE.pdf
Should be worried about PCBs in the old transformer oil, which are extremely cancer causing. Take it seriously and dispose of it properly.
You could probably replace that rectifier with a modern more efficient one, just bolted to a chunk of steel.
Thanks for the warning. I did keep the oil, grime and rags all separate and sealed. And I will look into where to dispose of it properly. I have reached out to find a different type of rectifier/system to up grade this one. The electrical side of the scraper is all new to me and I appreciate any help or tips I can get. All of the components are made by Letourneau so it might be a bit of a mixed bag to get it working again.
@ good luck! I can offer help, fascinated with those old machines.
Thanks man. I think it's such a cool piece of equipment and that it was way ahead of it's time.