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#1
10-03-2000, 02:12 PM
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Have a table saw powered by a three phase, 7hp, 24 amp motor. Problem is my local electric company does not offer three phase in my neighborhood. They would deliver service to my shop/garage for about $3,000. One alternative is a phase converter. Remanufactured delivered to my shop will run about $950 +/-; new about$1,350. Any cheaper thoughts? Can such a motor be rewired for traditional single phase, 220? Any other thoughts.
[This message has been edited by Jim Budde (edited 10-03-2000).] 
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#2
10-03-2000, 02:12 PM
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Have a table saw powered by a three phase, 7hp, 24 amp motor. Problem is my local electric company does not offer three phase in my neighborhood. They would deliver service to my shop/garage for about $3,000. One alternative is a phase converter. Remanufactured delivered to my shop will run about $950 +/-; new about$1,350. Any cheaper thoughts? Can such a motor be rewired for traditional single phase, 220? Any other thoughts.
[This message has been edited by Jim Budde (edited 10-03-2000).]
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#3
10-03-2000, 02:12 PM
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Have a table saw powered by a three phase, 7hp, 24 amp motor. Problem is my local electric company does not offer three phase in my neighborhood. They would deliver service to my shop/garage for about $3,000. One alternative is a phase converter. Remanufactured delivered to my shop will run about $950 +/-; new about$1,350. Any cheaper thoughts? Can such a motor be rewired for traditional single phase, 220? Any other thoughts.
[This message has been edited by Jim Budde (edited 10-03-2000).]
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#4
10-03-2000, 02:40 PM
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A new motor (7.5 HP, 1800 RPM, 230V, single phase, 215T frame, 36 Full Load Amps, Capacitor start) would be about $500, perhaps a lttle cheaper if you don't need TEFC. Try Grainger. A 3-phase motor in that size would be about $250, which is why they put it on in the first place. That's awfully big for single phase.
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#5
10-03-2000, 02:40 PM
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A new motor (7.5 HP, 1800 RPM, 230V, single phase, 215T frame, 36 Full Load Amps, Capacitor start) would be about $500, perhaps a lttle cheaper if you don't need TEFC. Try Grainger. A 3-phase motor in that size would be about $250, which is why they put it on in the first place. That's awfully big for single phase.
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#6
10-03-2000, 02:40 PM
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A new motor (7.5 HP, 1800 RPM, 230V, single phase, 215T frame, 36 Full Load Amps, Capacitor start) would be about $500, perhaps a lttle cheaper if you don't need TEFC. Try Grainger. A 3-phase motor in that size would be about $250, which is why they put it on in the first place. That's awfully big for single phase.
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#7
10-03-2000, 06:24 PM
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Jim,
You didn't say why you need so much HP (60" blade? re-sawing 12" hickory?). Most table saws do quite well with 2-3 HP motors. It should be easy to find a smaller HP motor that will handle all the heaviest normal shop activity. The 220V(single phase) models deliver more bang for the bucks that the 110V ones so. I would suspect that re-wiring it would be cost prohibitive in today's labor market. Hope it all turns out well for you. John
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#8
10-03-2000, 06:24 PM
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Jim,
You didn't say why you need so much HP (60" blade? re-sawing 12" hickory?). Most table saws do quite well with 2-3 HP motors. It should be easy to find a smaller HP motor that will handle all the heaviest normal shop activity. The 220V(single phase) models deliver more bang for the bucks that the 110V ones so. I would suspect that re-wiring it would be cost prohibitive in today's labor market. Hope it all turns out well for you. John
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#9
10-03-2000, 06:24 PM
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Jim,
You didn't say why you need so much HP (60" blade? re-sawing 12" hickory?). Most table saws do quite well with 2-3 HP motors. It should be easy to find a smaller HP motor that will handle all the heaviest normal shop activity. The 220V(single phase) models deliver more bang for the bucks that the 110V ones so. I would suspect that re-wiring it would be cost prohibitive in today's labor market. Hope it all turns out well for you. John
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#13
10-04-2000, 01:57 AM
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It is fairly simple to make a phase converter from an old electric motor. I have seen details in Home Shop Machineist. The converter will have to be a motor that is larger than the biggest you intend to run, and it will NOT be electricly efficent. You will loose some horsepower and it will cost more to run. Better not to fool around, buy a new motor.
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#14
10-04-2000, 01:57 AM
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It is fairly simple to make a phase converter from an old electric motor. I have seen details in Home Shop Machineist. The converter will have to be a motor that is larger than the biggest you intend to run, and it will NOT be electricly efficent. You will loose some horsepower and it will cost more to run. Better not to fool around, buy a new motor.
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#15
10-04-2000, 01:57 AM
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It is fairly simple to make a phase converter from an old electric motor. I have seen details in Home Shop Machineist. The converter will have to be a motor that is larger than the biggest you intend to run, and it will NOT be electricly efficent. You will loose some horsepower and it will cost more to run. Better not to fool around, buy a new motor.
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#16
10-04-2000, 08:45 AM
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While a single phase 7 1/2hp motor will be cheaper than converting to three phase power in your shop, it will be bigger than the three phase equivalent and will probably not fit on your saw. Like the others, I can't imagine why you need this much power. Try looking at a lower power single phase motor with a frame that will fit or can be fitted to your saw. The start-up current for a 7 1/2hp single phase motor will probably fry your wiring anyway unless you make special provisions for the saw.
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#17
10-04-2000, 08:45 AM
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While a single phase 7 1/2hp motor will be cheaper than converting to three phase power in your shop, it will be bigger than the three phase equivalent and will probably not fit on your saw. Like the others, I can't imagine why you need this much power. Try looking at a lower power single phase motor with a frame that will fit or can be fitted to your saw. The start-up current for a 7 1/2hp single phase motor will probably fry your wiring anyway unless you make special provisions for the saw.
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#18
10-04-2000, 08:45 AM
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While a single phase 7 1/2hp motor will be cheaper than converting to three phase power in your shop, it will be bigger than the three phase equivalent and will probably not fit on your saw. Like the others, I can't imagine why you need this much power. Try looking at a lower power single phase motor with a frame that will fit or can be fitted to your saw. The start-up current for a 7 1/2hp single phase motor will probably fry your wiring anyway unless you make special provisions for the saw.
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#19
10-04-2000, 09:23 AM
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Why 7 hp? That's what came with the saw. It is an old, very big and heavy commercial Rockwell from a local mill. I like the idea of just buying a 2 - 3 hp 220 single phase .... thanks for all the help.
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#20
10-04-2000, 09:23 AM
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Why 7 hp? That's what came with the saw. It is an old, very big and heavy commercial Rockwell from a local mill. I like the idea of just buying a 2 - 3 hp 220 single phase .... thanks for all the help.
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#21
10-04-2000, 09:23 AM
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Why 7 hp? That's what came with the saw. It is an old, very big and heavy commercial Rockwell from a local mill. I like the idea of just buying a 2 - 3 hp 220 single phase .... thanks for all the help.
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#22
10-04-2000, 08:50 PM
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Help is what we give and receive here Jim. I figure we all gain much knowledge from each others inquiries. I made a minor screw-up in my earlier post about choosing a 220V single phase over a 110V as most single-phase motors can be wired either way. Sounds like you're on the right track with a 2 or 3hp. One consideration you might watch for is matching the RPM of the motor to the saw blade diameter. I used to have a book about such and I'm sure the info is available from the net or at the library. Of course you can do the same with different pulley diameters. Sounds like you got one great saw set-up. I'm still making do with a benchtop 8" Shopmaster made sometime during Roosevelt's administration (his 1st or 2nd terms as WWII precluded such luxuries on the home front).
oops!..I almost forgot..put the 3-Phase monster up for sale on eBay and pay for the new motor and an evening out on the town  [This message has been edited by John058 (edited 10-04-2000).]
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#23
10-04-2000, 08:50 PM
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Help is what we give and receive here Jim. I figure we all gain much knowledge from each others inquiries. I made a minor screw-up in my earlier post about choosing a 220V single phase over a 110V as most single-phase motors can be wired either way. Sounds like you're on the right track with a 2 or 3hp. One consideration you might watch for is matching the RPM of the motor to the saw blade diameter. I used to have a book about such and I'm sure the info is available from the net or at the library. Of course you can do the same with different pulley diameters. Sounds like you got one great saw set-up. I'm still making do with a benchtop 8" Shopmaster made sometime during Roosevelt's administration (his 1st or 2nd terms as WWII precluded such luxuries on the home front).
oops!..I almost forgot..put the 3-Phase monster up for sale on eBay and pay for the new motor and an evening out on the town [This message has been edited by John058 (edited 10-04-2000).]
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#24
10-04-2000, 08:50 PM
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Help is what we give and receive here Jim. I figure we all gain much knowledge from each others inquiries. I made a minor screw-up in my earlier post about choosing a 220V single phase over a 110V as most single-phase motors can be wired either way. Sounds like you're on the right track with a 2 or 3hp. One consideration you might watch for is matching the RPM of the motor to the saw blade diameter. I used to have a book about such and I'm sure the info is available from the net or at the library. Of course you can do the same with different pulley diameters. Sounds like you got one great saw set-up. I'm still making do with a benchtop 8" Shopmaster made sometime during Roosevelt's administration (his 1st or 2nd terms as WWII precluded such luxuries on the home front).
oops!..I almost forgot..put the 3-Phase monster up for sale on eBay and pay for the new motor and an evening out on the town [This message has been edited by John058 (edited 10-04-2000).]
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