I purchased this EE yesterday. Its been sitting outside under a heavy tarp for several years. A small shop purchased it with some other equipment and never took the time to figure out how to convert it from 440 to 220. Thankfully it was covered in grease before it was put outside. I think I can figure out the mechanical side of this thing but the electrical I'm not sure about. Could it be as simple as swapping some wires and cleaning brushes/contacts to get it going? I have 220 from a 15 hp. rpc. Everything looks original except for the newer ac to dc transformer.
Whats the pulley for on the lower motor /generator? 4th image.
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54585[/ATTACH] What are the two pulleys with no belt for in the 3rd image.? Should there be something driving them?
Fortunately, the add-on exciter replacement also has a 230/460 primary.
Very likely, the coil of the main contactor is 460 only. As the source of replacement coils has dried up, a small 230 to 460 transformer can be installed to provide 460 for the "three-wire control station", which includes the coil.
While you're changing the feed rod belt, you should change the two spindle belts as well. They are often A85s, but DO CHECK as slight differences in spindle motor mounting affects the belt length.
[QUOTE=peterh5322;1834857]The machine is designed for 230/460 volts.
Fortunately, the add-on exciter replacement also has a 230/460 primary.
Very likely, the coil of the main contactor is 460 only. As the source of replacement coils has dried up, a small 230 to 460 transformer can be installed to provide 460 for the "three-wire control station", which includes the coil.
Whats the 3 wire control station? Would it be more trouble to run everything from a 220/460 transformer? I will try to get someone more qualified with the electrics to help get this going. Any info or advice is appreciated. Thanks
Does that belt run off the spindle with no pulley on the spindle or should there be a pulley there?
In most cases the flat belt runs directly on the end of the spindle. On machines with a factory collet closer the flat belt ran on a section of the closer body, which slips over the end of the spindle. If you have 3 covers for the headstock end of the machine it probably originally had a factory collet closer.
Peter is suggesting a small transformer just to run the main AC contactor. The AC contactor is located under a cast cover on the back of the gearbox. (The cover has a round hole in the center and is above the orange and green boxes on the back.) Please post a photo of the contactor.
Another problem that you may have is that the overload heater for the AC contactor may be set for 440 operation. If so, the overloads will trip at about 25% power. The only way to change that is to change the heaters and they aren’t available for the original contactor either.
The green box of the back of the base looks like it might be some sort of transformer. What does the plate on it say?
The “3-wire control station” is the plate with start and stop buttons on the front of the machine, at knee level.
I would not suggest trying to run the entire machine using a transformer unless you have commercial 3-phase power. A transformer that can handle the load is huge. A typical 7.5 HP rotary phase converter on a 30 Amp circuit may not be able to even handle to current inrush of transformer alone.
At the tip of the pin it says 220/460/208
Second picture is the green transformer on the back.
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Something's not quite right about the number from the coil. I would expect it to read "220V,60CYC - 208V". In any case it appears to be a 220/240 VAC coil, so that's good. The green transformer was probably used to drop 480VAC to 240 for the contactor. Nothing else on the machine looks to be 220, so that transformer is serious overkill for the job.
You appear to be in good shape for a conversion to 240. Based on the photo of the terminal panel on the motor/generator (MG), the MG is currently wired for 440 operation. It's a simple matter to change that. The big box under the tailstock is a single phase transformer. I suspect that the box mounted on its left side contains a bridge rectifier. Together the transformer and rectifier provide the 115 VDC that the generator and DC control panel need. As you have noted, the transformer can be converted to operate from 240 VAC. I can't really tell, but it looks like it might have some taps on it so that you can set it up to output a higher voltage than 120 VAC. If it just put out 120 VAC, the rectifier will only put out about 90 VDC, so you want maybe 150 VAC going into the rectifier to get 115 VDC out.
You won't need the green transformer on the back; you can power the main AC contactor directly from the incoming 240 VAC. Are you planning to use a rotary phase converter?
Beyond the above, you'll need to change the overload heaters and the probably the main fuses. Again, see my conversion checklist for details.
The overload heaters pose a problem. I'm not aware of a source of heaters for 240 operation; Brazil Electric used to have them but I guess we've exhausted their supply. One possibility is to put a resistor in parallel with each heater; unfortunately I don't know what value to use and it's not possible to measure the resistance of the heater with a garden variety Ohmmeter. On the other hand, a second 480 heater in parallel with each existing heater will do the trick nicely. Lots of guys here have converted their machines from 480 to 240, so it should be a matter of asking to find a pair.
Yes Cal the coil reads "220V,60CYC - 208V". not the other. Things are starting to make a little more sense. I have a 15hp rpc I plan to use. Would a 240 coil from a different machine work? Or would that be more trouble? Thanks
Yes Cal the coil reads "220V,60CYC - 208V". not the other. Things are starting to make a little more sense. I have a 15hp rpc I plan to use. Would a 240 coil from a different machine work? Or would that be more trouble? Thanks
I don't know that there was such a thing. 240 is the new 220 (see Peter's posts on the subject). A 220 coil will work just fine.
Something's not quite right about the number from the coil. I would expect it to read "220V,60CYC - 208V". In any case it appears to be a 220/240 VAC coil, so that's good. The green transformer was probably used to drop 480VAC to 240 for the contactor. Nothing else on the machine looks to be 220, so that transformer is serious overkill for the job.
You appear to be in good shape for a conversion to 240. Based on the photo of the terminal panel on the motor/generator (MG), the MG is currently wired for 440 operation. It's a simple matter to change that. The big box under the tailstock is a single phase transformer. I suspect that the box mounted on its left side contains a bridge rectifier. Together the transformer and rectifier provide the 115 VDC that the generator and DC control panel need. As you have noted, the transformer can be converted to operate from 240 VAC. I can't really tell, but it looks like it might have some taps on it so that you can set it up to output a higher voltage than 120 VAC. If it just put out 120 VAC, the rectifier will only put out about 90 VDC, so you want maybe 150 VAC going into the rectifier to get 115 VDC out.
You won't need the green transformer on the back; you can power the main AC contactor directly from the incoming 240 VAC. Are you planning to use a rotary phase converter?
Beyond the above, you'll need to change the overload heaters and the probably the main fuses. Again, see my conversion checklist for details.
The overload heaters pose a problem. I'm not aware of a source of heaters for 240 operation; Brazil Electric used to have them but I guess we've exhausted their supply. One possibility is to put a resistor in parallel with each heater; unfortunately I don't know what value to use and it's not possible to measure the resistance of the heater with a garden variety Ohmmeter. On the other hand, a second 480 heater in parallel with each existing heater will do the trick nicely. Lots of guys here have converted their machines from 480 to 240, so it should be a matter of asking to find a pair.
Cal
Thanks everyone for the advice. I may try the 480 heaters in parallel. Would anybody have any extras they would part with?
CUTLER HAMMER 9586 H 1374B THERMAL OVERLOAD HEATER COIL 2 PACK NEW IN BOX
Are these the heaters I need? Thanks
AFIK, that's the right number, but I don't have any way to verify it. I've been trying to find a copy of the Cutler-Hammer overload heater table with no success. I'm not sure about the B suffix, but they sound like the right ones. The 9586 part refers to the contactor itself, so that part is right. Go for it.
I don't think I have the taps for the higher voltage. With the help here I think I have the rest figured out. Here are some pictures of the transformer and rectifier. Is the blue thing a rectifier?
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