# Table Saw Motors



## libra123 (Sep 25, 2011)

Hi Here I am again seeking information from the pros. I recently purchased a 9" Old Rockwell Beaver table saw with a worn out 1 H.P. motor. I have a 1 3/4 H.P. motor and enquire if this is safe on this type of saw.
Also does any one know where I can find information on hooking up the motor to the power switch.
I am new to this type of thing and enjoy repairing and working with older equipement.

Any help here will be appreciated .

Thanks

Arne
Libra 123


----------



## DaninVan (Jan 1, 2012)

Arne; I'm guessing that you've checked out the attached plate with the motor specs on it(?). Assuming it's either 120V or dual 120/240V, and the rpm is the same, yes. It'll likely be a significant improvement. A good time to maybe switch to a link belt as well.
You may also want to consider upgrading the saw's supply cct to 20A, if it's 120V.
It'll just eliminate annoying cct. breaker pops while you're putting a load on the saw motor. My compressor does that intermittently, if I use a 12/3 extension cord ...p..i..t..a!
(Breaker _and_ wiring upgrade.)


----------



## Cherryville Chuck (Sep 28, 2010)

Dan may be right about the 20 amp circuit. The motor should run at no load on a standard circuit but might draw too much under load. Your motor plate will tell you. 3 other things to consider. Are the mounting plates the same? Does the new motor spin in the same direction? And, are the rpms the same (close i.e.)?
Most motors will run better on 220 v than 110. If you can run it this way I recommend it. The motor connection cover plate will show you how it is done. You can still use the same switch. Only one wire on 220 needs to be switched. The other can remain live all the time. 
Every motor is different for connections. Some can be reversed, some can be wired for single or dual voltage. Step motors can be wired for different rpms. If you don't know how, you need to find someone that can.


----------



## bclarknc (Feb 28, 2012)

A main point I think you're asking is what's a good size motor for a table saw. All the old Craftsman one's I've gotten recently are only 1 HP or maybe 3/4. I did get another one cheap that was 1.5 hp. I am also interested in what you guys know about what are the best size motors to use. Obviously, bigger is better, but more interested in what smaller ones will work fine. I also need to ask this in another section about jointers, bench sanders, etc. I've found a lot lately that range from 1/6 to 1/5 hp and I'm wondering what I can use those sizes for.


----------



## PRDarnell (Mar 21, 2012)

*Old Woodworking Machines*

Arne,

I don't want to discourage you or anyone from asking good questions like this. However, everyone should know about another forum to which I've belonged for quite a few years -- the Old Woodworking Machines forum at owwm (dot) org moderated by Keith Bohn. 

I'm not active right now but there is a wealth of information as well as many knowledgeable folks. Your question is similar to ones others have asked. If you go over there to ask your question, don't be surprised if you don't get anything done for several hours. 

Tell them I said, "Hi!"

Paul Darnell
Syracuse, NY



libra123 said:


> Hi Here I am again seeking information from the pros. I recently purchased a 9" Old Rockwell Beaver table saw with a worn out 1 H.P. motor. I have a 1 3/4 H.P. motor and enquire if this is safe on this type of saw.
> Also does any one know where I can find information on hooking up the motor to the power switch.
> I am new to this type of thing and enjoy repairing and working with older equipement.
> 
> ...


----------



## Dmeadows (Jun 28, 2011)

Cherryville Chuck said:


> Dan may be right about the 20 amp circuit. The motor should run at no load on a standard circuit but might draw too much under load. Your motor plate will tell you. 3 other things to consider. Are the mounting plates the same? Does the new motor spin in the same direction? And, are the rpms the same (close i.e.)?
> Most motors will run better on 220 v than 110. If you can run it this way I recommend it. The motor connection cover plate will show you how it is done. You can still use the same switch. Only one wire on 220 needs to be switched. The other can remain live all the time.
> Every motor is different for connections. Some can be reversed, some can be wired for single or dual voltage. Step motors can be wired for different rpms. If you don't know how, you need to find someone that can.


 I would highly recommend switching both sides of 240. Yes, switching one will stop the motor, but as you said, the motor windings will still be live. Not the best idea from a safety standpoint!


----------



## Flint54 (Sep 26, 2011)

I agree, switch both sides of the 220/240. I am in the process of building a new backyard shop. It will be 12 X 32 when completed. I am wiring it also and will have several 220 outlets along with 110. The 220 outlets will be for the heavier duty items such as my table saw, band saw etc. More efficient for these motors.


----------



## MikeMa (Jul 27, 2006)

The most important thing here is making sure the RPMs are the same. This should be 3450rpms Also you may need a new switch that is rated from the increased amperage or if going from 110v - 220v


----------



## RJM (Apr 11, 2010)

NiceG316 said:


> The most important thing here is making sure the RPMs are the same. This should be 3450rpms Also you may need a new switch that is rated from the increased amperage or if going from 110v - 220v


It should be the same rpm as as the one that's already in there. I'd bet that it's 1725 (which usually costs more -4 poles vs 2).

Also, it should be a closed frame motor (i.e. TEFC - totally enclosed fan cooled).

Assuming a motor can be wired for 120 or 240, it will run fine on either. With 240, it will just use 1/2 the current.

Definately use a proper switch for 240. Don't mickey mouse it by switching only one line. I don't even think that's legal.

I asume the replacement moter is an induction motor, not a universal motor (like on a router).


----------



## Cherryville Chuck (Sep 28, 2010)

I have to disagree with all on the switch issue. The proper safety procedure is to lock out the motor by turning the breaker off before working on it whether it be a single pole switch and motor or a double pole. There is no possiblity of a shock or accidentally energizing the motor that way.


----------



## DaninVan (Jan 1, 2012)

...or just unplug it.


----------



## libra123 (Sep 25, 2011)

Thanks for your help.
Libra 123
Arne


----------

