Reversing Rotation of 115V Table Saw Motor

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sandiegoman
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Reversing Rotation of 115V Table Saw Motor

Post by sandiegoman » Wed Aug 04, 2004 8:15 am

The last motor I had on my table saw went bad and the industrial parts liquidators by my house only had 1 that rotates the opposite direction for what I need. It would be a major hassle to remount the motor, so I am trying to find out if I can rewire it to change the rotation from CCW to CW.<p>It is a Chicago Electric Power Tools motor SKU S 30188 - Type-CP PH-1 ENC-DP 2HP Volt 115/230<p>There was some information about the wire color for the low voltage, but I really don't understand it. <p>Yellow/Blk - 1 Line 1
Red - 4
Orange/Brown - 5
White/Yellow - 6 Line 2<p>Any help would be greatly appreciated.<p>Bryan

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Edd
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Re: Reversing Rotation of 115V Table Saw Motor

Post by Edd » Wed Aug 04, 2004 11:59 am

Bryan :
MMMMmmmm …2 Horsepowders !!!! that would really make my 10in table saw spin…especially if it was at 3450rpm!
There is some bit of info still needed on the motor for a more involved analysis, but lets go with what you supplied. The relevant reference to low voltage naturally is the positioning of the connector wire/tabs to the appropriate mates to shift operation of the motor between 115/220VAC operation. Typically if there was a start phase shift connection to be used in directional control it also would have been noted on the motors side info plate. What I might suggest is also the simplest if it proves to be the manner of your AC motors mechanical construction. Examine the motor to see if there are two metal end plates on each end of the motor with each of them flange recessed slightly into the whole motors center cylindrical housing which contains your motors stator windings along with its stator pole piece laminations. The motors center rotor spins down within the center of this assembly, with one end of the rotor shaft coming out for your use. Now inspect the motor end plates and verify that they are secured by 4 long bolts running internally between the two end plates. If so make some reference tics/scratches/marks on each end plate plus the frame for ease of realignment of the plates and motor body later on . Pull the end plates and slip out the rotor , watching and taking note of location(s) of any spacers, washers, compression springs…that might slide from the rotors shaft if you are clumsy and tilt it away from its hoz position. Take note of the rotor shaft and take note that the laminations gaps are arranged in a peripheral spiral slope. This in reference to the companion stator pole lam pieces determines the rotational direction. So basically what you want to do is just rotate the whole rotor and its end plates 180 degrees in respect to the way that it initially was, and naturally the end plates will fall into place…since only one had the shaft passing thru it. Reassemble the unit that way and the motor shaft should now magically be rotating in the opposite direction …all with no floobydust being involved.<p>73's de Edd
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Mike
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Re: Reversing Rotation of 115V Table Saw Motor

Post by Mike » Thu Aug 05, 2004 4:15 am

if its that complicated, how do they make ceiling fans that can go either way? They run off AC.

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Chris Smith
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Re: Reversing Rotation of 115V Table Saw Motor

Post by Chris Smith » Thu Aug 05, 2004 1:17 pm

Some types of motors go both ways, its in the wiring. They will mark them on the plate as such.<p>For your possible cure,....Simply mount the motor the other way around, place it backwards and on the other side of the belt line. <p>If it has two shafts on the motor, use the other side shaft.

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Re: Reversing Rotation of 115V Table Saw Motor

Post by dyarker » Thu Aug 05, 2004 1:20 pm

Different kind of AC motor. Some easier to change direction than others.
Dale Y

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jollyrgr
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Re: Reversing Rotation of 115V Table Saw Motor

Post by jollyrgr » Thu Aug 05, 2004 3:58 pm

It depends mainly on the motor style as to how you go about reversing its direction. In some cases it is not easily done. <p>I did some searching and found that Harbor Freight Tools carry "Chicago Electric Power Tools" line of products. I even found a 1.5 HP motor with a similar SKU to what you posted. Go to:<p>http://www.harborfreight.com<p>In the SEARCH BY ITEM NUMBER on the left hand side of the page put in 30188. There you will find the motor I believe you have. The rest of my comments will be based on the assumption that I have indeed found the motor you are referring to.<p>According to the Harbor Freight web site this motor is NOT reversible and runs only CCW. Read the description carefully and you will see that this is most likely the motor you referred to as it was rated by some compressor manufacturers as being a 2 HP motor. It sells for $79.99.<p>While I would assume that the "not reversible" is not really true and is more likely "not easily reversible" it might not be worth the effort. One trick I used to use on motors was to pull the end caps off and flip their sides. In other words the front housing became the rear and vise versa. Of course the shaft got flipped around as well. This worked fine on low horse power motors like those found in desk fans etc. <p>Harbor Freight is also selling item number 3068. This is a "56 frame" with 5/8" shaft motor that has 5 HP and sells for the same price. This motor IS reversible. They also sell item number 3067 which is a 3 HP version of the motor I believe you have and this one is reversible as well. It is $10 cheaper than the price of the 30188 motor.<p>If you got the motor you listed at a killer price I'd say it might be worth the effort. If you have not bought the motor I'd hold off on attempting to buy it and track down a motor that is reversible. You could end up being able to reverse the motor you have been investigating but at the expense of voiding any warranty it might have since it is listed as "not reversible". <p>Note that Harbor Freight claims to be the "exclusive distributer" of this item. They also have manuals for many of the items right on the web site. When looking at the page for the motor scroll down and look for the green "DOWNLOAD PRODUCT MANUAL" button/link below the ADD TO BASKET link in order to see the manual. The wiring setup information is near the end of the manual.
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High4Volts
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Re: Reversing Rotation of 115V Table Saw Motor

Post by High4Volts » Fri Aug 06, 2004 1:01 am

You would do better by replacing that Chicago Electric motor with something like Dayton. You'll pay a little more now for it but it will last 10X longer. I swear they have small horses in china .
:D
I'm wondering, did the old motor by chance have a start capacitor on it that just went bad?

Mike
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Re: Reversing Rotation of 115V Table Saw Motor

Post by Mike » Fri Aug 06, 2004 3:30 am

Jolly Roger, I hate to say your long post may have been a waste, but he said he needs to make a CCW motor spin CW. The motor you talk about is CCW only and not reversable.

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Re: Reversing Rotation of 115V Table Saw Motor

Post by Dean Huster » Fri Aug 06, 2004 5:39 am

Edd, a 10", 1hp table saw is underpowered. When I'm working with oak or am ripping a lot of big stock, my 1hp drags 'way too much. I have a 2hp 3450 rpm motor that I'd like to use but am in a similar quandry as Bryan ... I just haven't opened the motor up yet. This kind of stuff makes you wish for readily available 3-phase power. By the way, 3450 rpm is the usual motor speed needed on table saws, shapers and jointers. The low-speed motors are for the drill press and lathe. If you're running a low-speed motor on your saw, you're killing yourself, especially if you have a big pulley on the motor and a little one on the saw arbor to get the speed up (and the torque 'way down!).<p>Dean
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Re: Reversing Rotation of 115V Table Saw Motor

Post by perfectbite » Fri Aug 06, 2004 8:36 am

Mike, As you have probably realized by now there are 2 types of motor wirings. One internal to the motor and basically hard-wired, and one to make the power connections which, depending on the motor's application, (110/240. CW/CCW) are user accessible 'soft 'wired. One of the reasons Dean wrote:
"This kind of stuff makes you wish for readily available 3-phase power." is that by simply reversing any 2 leads of the 3 leads powering a 3 phase motor the motor's direction of rotation is changed. (I've read of one horror story where a very large 3 phase exhaust fan on the roof of an office building had been working in reverse and the building owner had spent $10s of thousands before an on the ball air balancing contractor discovered the ultra-simple solution to the owner's 'sick' building syndrome.) Another reason is that 3 phase power is very smooth power. Not worth transforming to get though normally.<p>On a related subject, (I think it may be related, please correct me if I am wrong), quite a few years ago I saw a couple of DIY plans for a power saw, basically a weighted reciprocating hacksaw. I find myself in need of one now. Has anyone had any experience with these? and could they recommend a design/cheap kit?
(I can't use a metal chop saw, chiefly because of the sparks but also because they are noisy.)

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jollyrgr
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Re: Reversing Rotation of 115V Table Saw Motor

Post by jollyrgr » Fri Aug 06, 2004 2:30 pm

<blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr>Originally posted by Mike:
Jolly Roger, I hate to say your long post may have been a waste, but he said he needs to make a CCW motor spin CW. The motor you talk about is CCW only and not reversable.<hr></blockquote><p>If you re-read my post I state that myself. In fact I go on to suggest two other motors that Sandiegoman should use instead of the motor he suggested. Both of those say they are reversible and have manuals that explain how to do so. I also point out where the manuals to the motors can be downloaded. Unless he already owns the CCW motor I suggested that it is not worth the effort. Hope this clears up any confusion I may have left by posting a long post.
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Re: Reversing Rotation of 115V Table Saw Motor

Post by rshayes » Sat Aug 07, 2004 12:10 am

The motor appears to be a single phase capacitor start induction motor.<p>A single phase stator does not generate a rotating magnetic field. That takes two, three, or more phases. A motor can run with a single phase stator if it is started and brought up to speed by some other method. This is usually a starting winding, whose phase is shifted by a series capacitor. The motor is started as a two phase motor, but runs as a single phase motor. The starting winding and capacitor are switched out by a centrifigal switch after the motor starts. The capacitor is usually an electrolytic capacitor that is unsuitable for continuous operation.<p>There are two mechanical reasons why the motor might not operate properly in the reverse direction:<p>If the motor has an interior cooling fan, the air flow may be insufficient if the motor is running backwards.<p>Some designs of centrifigal switch may not operate properly in the reverse direction.<p>Otherwise, the direction of rotation is determined by the phase of the starting winding.<p>The Harbor Freight Tools manual on the 3067 motor is a little clearer. It shows six winding connections brought out. The running winding is split into two 110 VAC sections, from 1 to 2 and from 3 to 4. On 110 V these sections are wired in parallel, 1 is connected to 3 (line 1) and 2 is connected to 4 (line 2). On 220 V, these are connected in series by connecting 2 to 3 (pigtail). Terminal 1 (line 1) and terminal 4 (line 2) remain the power connections.<p>The starting winding is a single 110 V winding in series with a capacitor. This would be connected from terminal 5 to 6. On 110 V, the starting winding and capacitor are connected across the AC line. The connections are interchanged to change the direction of rotation.<p>When operating on 220 V, the two running windings are connected in series. The "pigtail" is the intermediate connection between them, and will have a voltage of 110 volts with respect to either line connection. In effect, the two running windings become an autotransformer. The starting winding is connected from the center tap (pigtail) to one side of the AC line, so that it is still operating on 110 VAC. Again, the direction of rotation is changed by reversing the starting winding leads.<p>The same windings are probably present on the 30188 motor, but not all of the leads are brought out. The starting winding may be connected inside the motor. If the starting winding leads could be located and reversed, the motor rotation should also reverse. This would probably void the warrenty on the motor, since it was not a use recommended by the manufacturer.<p>[ August 07, 2004: Message edited by: stephen ]<p>[ August 07, 2004: Message edited by: stephen ]</p>

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MrAl
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Re: Reversing Rotation of 115V Table Saw Motor

Post by MrAl » Sat Aug 07, 2004 3:13 am

Hi Bryan,<p>The first thing i would do is try to contact
the manufacturer to ask if they have any info
on reversing the motor and if it is even
possible and if it's possible if it's a good
idea.
Probably call first, email second, write third.<p>If that didnt work, i'd probably look for a motor
that does what i want it too rather then take
apart the motor to modify it unless there was
some definite procedure that would make sure
it was going to work both electrically AND
mechanically.<p>Take care and good luck,
Al
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sandiegoman
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Re: Reversing Rotation of 115V Table Saw Motor

Post by sandiegoman » Sat Aug 07, 2004 12:02 pm

Thanks everyone for all the input. The old motor actually states that it is reversible on the plate by reversing the wires. But on this second motor, it does not state the same information. They are both from the same company, same HP, etc... <p>The old motor appears to be in better condition, but it does not operate under load. It was supposedly rebuilt about a year ago... But since I was in a bind and short on cash, I opted to get the CCW motor and run the wood through the opposite direction.<p>Anyways, I am going to contact Chicago Electric about this and see if they have any ideas, otherwise I will be remounting the existing motor with a handy-dandy new mounting plate. <p>Thanks for all the input!<p>Bryan

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Re: Reversing Rotation of 115V Table Saw Motor

Post by toejam » Sat Aug 07, 2004 4:54 pm

you can turn the blade around and use the other side of the saw but you have to double nut the blade.

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