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i've got a sears table saw with a 1 3/4 hp motor

it can be wired 110 or 220

right now i have it for 110 if i switch it to 220 will that make it stronger for cutting??

what are the advantages of 220
 

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Cabinetmaker
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Yes it will. Runs better by far. Also half the amps ( a tad cheaper )
A motor that is 110/220 capable that takes 15A at 110 takes 7.5 amps at 220V and techinically gets a tad more power :}:}:}:} .
My Delta is rated at 1.5 hp @ 110 and 2.0 at 220
JackM
 

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110V vs. 220V

You probably don't want to hear this, but:

First, the internal windings of "small" electric motors run on 110V even when 220V is supplied to the motor's wiring plate.

Also, it's a common misconception that a motor running on 220V use less current and will generate more power than the same motor running on 110V. It won't.

While it's true that the motor will draw 15A at 110V and 7.5A at 220V, that 7.5A is per leg, and there are two legs (two hot wires), therefore it still uses the same 15A. At 110V there is only one leg (one hot wire), hence the 15A.

As to power, Power = Volts x Amps. So at 110V and 15A, the power is 1,650 Watts, or roughly 2 HP. Given that the houose voltage is probably not a constant 110 volts, and in fact can did as low as 90-odd volts, the voltage supplied to the sub-panel will also be less than 110V. Couple that with any small IR drop in the wire, outlet, cord, etc., you can see how the voltage could be significantly less than 110V, and so the "power in" would be lower also (and the output power cannot be more than the input power).

For 220V Power still = Volts x Amps. Double the Voltage and halve the Amperage and you still have the same P = Volts x Amps, or 1,650 Watts, and the same roughly 2 horesepower. You can't increase a motor's power by rewiring it to run on 220V.

To sum it all up:

1. The motor's power will be the same whether wired for 110V or 220V.

2. Using 220V allows the use of a smaller wire (not a significant cost saving).

3. 220V can be wired from a single douoble pole breaker. Note that I said double pole, not two pole. There is a difference.

4. There may be a tiny reduction in total circuit amperage, which will give a tiny reduction in Watts as recorded by the electric meter on your house, but it not even be measurable or noticeable on your bill.
 

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110/220 comps

One thing you will notice is that the blade comes to speed immediately which will reduce the start up energy draw but like Peter said, the energy costs are not reduced and the horsepower is not increased. 1½ HO is the same regardless of the power supply except in relation to voltage drops that will reduce your available horsepower. So, think of HP as the maximum developed when all incoming power conditions are as expected.

Ed
 

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I had always heard that running at 220 didn't generate as much heat so your motor life would last longer and that it didn't get "bogged" down by a lack of draw from the power source. Beats - I figure there's a reason why you have the option though.
 

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Motor Heat

That's another misconception. If the power stays the same (and it absolutely does) the heat generated will be the same. Again, it's voltage times current.

~ Peter
 

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I was thinking a 220 motor had more startup torque and was going to tout this as a response but before I made a fool of myself I asked my dad who shot that down in flames.

PB is right there is no real power advantage of 220 over 110 even in the startup it is a myth to which I have fallen prey for many years.

I would rather be publicly enlighted than to remain silently ignorant thanks Peter.
 

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State of confusion

so is there any real reason to use 220 over 110?
I'm new here and in the confusing stages of looking at table saws and am very interested in this question. Furthermore, is there a saw out there that will run in the US (110/60hz) and in Europe (230/50hz)? That would be very interesting to me as I am in the military and bounce between Europe and the US as much as possible.
 

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Generally speaking a motor of 1 to about 2 or 3 hp can be switched from 110V to 220V, but motors are designed to run at either 50 hz or 60 Hz only.

I would check with some saw manufacturers that you're interested in.

~ peter
 

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The advantages from using 220V rather than 110V are:

1. the double pole breaker can occupy a single space in the service panel and still cut out both 240V hot wires; and

2. Because the power is split between the two hot wires a smaller gauge wire can be used.

3. It is possible to get two 110V feeds from a 220V line in a work box.

Peter
 

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Question

having usedtable saws for yrs I have ripped 2x4s on t.s.'s with both 220 and 110 on the same saw by switching the wiring the saww didn't bog down with the 220 but did with the 110 why?
 

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tablesaw motor

The reason the breaker doesn't trip as easily on 220volt as on 110 volts is something called voltage drop. Voltage drop happens when the wire between your breaker panel and the motor heats up under increased load and the current increases to make up for the lower voltage. Since the current on each leg of 220 is half what it was on 110 you are not anywhere close to the maximum current rating of the breaker. Thus it doesn't trip.
 

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I did some basement rewiring about a month ago and changed both my Ridgid 3660 table saw and Craftsman RAS over to 220 (actually 240). I was hoping for a little extra power and for the saws to spin up to speed quicker.

The result was no change at all that I can notice. This might be because both saws were wired with 12 gauge wire to start with so voltage drop was probably not a problem even on 110.

Bill
 

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While it's true that the motor will draw 15A at 110V and 7.5A at 220V, that 7.5A is per leg, and there are two legs (two hot wires), therefore it still uses the same 15A. At 110V there is only one leg (one hot wire), hence the 15A.


Peter,
You are running a TS on 110V and it is pulling 15 amps using 12 ga. wire. (one hot leg)

You are running the same TS on 220V pulling the same 15amps on 12 ga. wire (two hot legs 7.5amps per leg)

Would the line loss be less by only pulling 7.5 amps per leg under load (220V)versus pulling 15 amps per leg under load (110V), thus you would have more power available because of the decreased line loss with the 220?

Wouldn't the ampacity of the wire and length of the wire run have to be part of this calculation also?

Peter don't take what i posted as disagreeing with you it's just a question.
 

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Very interesting reading. I have not wired my shop yet. Is there any equipoment that I should buy in the future that I should buy 220V?

I realize that heat and a/c would require 220V, I have no plans to run either in the shop.

Questiojn is, since I'm not going to run heat and air to the shop, would I ever need 220V? Is there a piece of equipment that I may purchase in the future that is simply best suited for 220V?

I've been useing the shop for the past year with 2 drop cords running from the house to get buy. :laughing:

Any suggestions, thoughts would be appreciated.

RLH :thumbsup:
 

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Air compressor, welder, and a Cabinet saw 3hp+, most 2hp dust collectors, jointers etc will all require 220v. If you haven't run the electrical yet it would be foolish not to run a few 220V lines for future use. I would also add, I think it was my Cabinet saw that required a 4 prong 220v line which is why I was glad to have thought ahead and ran 10-3 w/ground for my table saw and compressor. Nothing like having to fix/rewire after the walls are closed up because you didn't think ahead.

If a 110v 15 amp motor is bogging down down because you are overloading the circuit then that same motor on 220v will run better and last longer because the the amps are split over to lines. 110v lines usually have multiple outlets where as 220v lines are generally dedicated lines. It's the overloaded circuit versus a dedicated circuit that I think makes most people think 220v gives more power the 110v.
 
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