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Hey, registered here a year or so ago, and I finally bought my bandsaw. I ended up picking up an old rockwell on craigslist the other day. I guess my main question is, its currently wired for 230, but can be set for 115. Is there any benefit to keeping it at 230. I ask because the 230 plug isnt the most convenient to get to. Will the motor still run 1 hp on 115 or will it only put out full power on 230. I am planing to resaw a piece of maple thats 7 in tall once I get it set up, so if the 230 will help I will just get a longer cord.

thanks
 

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When it's wired for 220,I think the amperage is split onto 2 110 legs so it won't tax the breakers so much. The plate of the motor should have amp ratings for 110 and 220 (115-230). The 220 is usually half of the 110.

"http://74.125.113.132/search?q=cache:O3bAFi8iAd0J:sawdustmaking.com/ELECTRIC%2520MOTORS/electricmotors.html+1+hp+motor+ratings+amperage&cd=1&hl=en&ct=clnk&gl=us"
 

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Probably more flexability in where you can position it in your shop at 110. Not sure there would be any real benefit of running at 220.
 

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The bandsaw would start up faster if it's on 220, but probably no more than seconds. Note that if you wire it to 220v you can afford to use a lighter gauge extension cord, or a longer cord, compared to 115v. And it's possible that serious resawing your motor will draw more amps (cast iron wheels are better though) and pop a 115v 15amp breaker. Worse if you run a DC on the same circuit while you're sawing
 

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If its more convenient to run it at 120 v, then I would say do that. With 240v the motor will start easier as stated before but it won't be cheaper to run it, because watts(hp) stay the same regardless of the voltage.
 

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If you go the 110 route make sure you change out the existing receptacle with a 20 amp rated receptacle. Most of the receptacles sold today are rated at 15 amps. This small detail does make a difference.

However, 220 volts would be best if you can swing it.
 

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1 HP = 746 watts. Figure 60% efficiency for an induction motor. So it takes roughly 1250 watts to produce the max 1hp power. Watts=Volts*Amps. So, figuring for some voltage drop in the line, we get 1250/110 = 11.4 amps at 110v and 5.7 amps at 220v. Even at 11.4, you are still well within the safe range of your average household 15amp breakers.

Where 240v becomes more important is in motors in the 1.75+ HP (20amp) range. At that point, you are not getting full power to your motor because you cannot supply it with enough current.

You are billed for power by the watt (actually kilowatt/hour). The voltage doesn't matter.
 

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I wish you guys would forget you ever heard 746 watts = 1 hp. It is nearly twice that for single phase motors. 1 hp motor nameplate will be close to 16 amps on 120 volts and 8 amps on 240 volts. Code requirements for 1 hp motor are #12 wire and 30 amp breaker for 120 vlts and #14 wire and 15 amp breaker for 240 volts.
 
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