Replies

1. 
   James2007 | Jul 02, 2009 07:53pm | #1

   I'm sure someone will correct me if I'm wrong, but generally speaking line voltage is within +/- 10%, or in this case +/- 24 volts. I've worked mostly with 3 phase motors, but my experience is that you need a significant voltage change to cause problems.

   James

2. 
   JerryPacMan | Jul 02, 2009 09:15pm | #2

   Motors like up to 10% higher voltage, you are good to about 264 volts.

    

   Life is what happens to you when you're making other plans.

   When your ship comes in... make sure you are not at the airport.

3. 
   northhouguy | Jul 03, 2009 01:52am | #3

   Okahun,

   You're OK.

   These days, as the load on the electric utility's distribution system changes, you'll see system voltages vary somewhat.  If you measure the voltage at the peak use time of day you'll probably see it closer to "nominal", (in this case 240 V).

   As stated previously, motors, although nameplated with a nominal voltage, are required to be built to operate over a range of voltage.  Motors don't mind higher voltages, to a point.  But lower voltages?  Now that's a different story.

   Use your tools, enjoy them and post some pictures of your results.

   Regards,

   Fred

    

   PS My spelling is so bad even the spel cheKkerer can't find my mistakes.  Sorry for the edits.

   ---

   Edited 7/2/2009 6:52 pm ET by northhouguy

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   Edited 7/2/2009 6:53 pm ET by northhouguy

   
   

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   Edited 7/2/2009 6:54 pm ET by northhouguy

4. 
   okahun | Jul 03, 2009 05:18pm | #4

   To everyone that replied THANKS (James2007, JerryPacMan and Fred)
   I had Back Surgery in January and unable to do any woodworking until I'm healed. So being bored I turned on my bandsaw (Steelcity 14" granite table with a riser kit) to play with and the motor had a vibrations and noise it didn't have before. The saw is brand new, bought last September and used maybe 10 to 15 minutes max and that was just testing and setup. When I bought the saw it was wired at 120 volts and ran find until I changed it to 240 volts. That was the start of my problems, Steelcity sent me start and run capacitors which I installed, motor still made noise. Then they sent a new motor I installed it everything seamed to be fine. Well fast forward to the other day and problems are back. I tried to start it after I posted my question and man it's howling (I guess were past the vibration and noise) just like the first motor, so I know it's again a start capacitor. I hope their dual voltage 1 1/2 HP motors aren't all defective. I'm happy with Steelcity's customer service, they help all they can, send any parts etc., I explained my situation and they said they will take care of me when I'm able to do anything. Sorry for going on and on reminds me of the movie "Airplane" the scene where the lead actor (can't think of his name) is telling his story and people next to him are killing themselves. Thanks again for all your help

5. 
   JohnWW | Jul 03, 2009 05:50pm | #5

   Unless you have a meter that is marked that it uses the RMS method of measuring AC voltage, which is generally only seen in better quality meters, the voltage readings you are getting are only an approximation. As stated by others, higher voltages, within reason, aren't a problem.

   I would ask Steel City for a new motor, your problems are uncommon, I doubt if bad capacitors are the sole source of your problems.

   John White
   Shop Manager for FWW Magazine, 1998-2007

1. 
   okahun | Jul 03, 2009 06:28pm | #6

   Thanks for the reply John
   The DVM I have is an inexpensive one. I have an Ideal Vol-con Elite but that only lights up the 240 bar there isn't any digital readout. Talking with Steel City customer service he mentioned the power switch maybe send me one rated for 240 volts when I'm able to replace parts. Don't you think it's unusual that two brand new motors go out with what appears to be the same problem?
   I got your book "Care and Repair of Shop Machines" good book, thanks.
   okahun

1. 
   JohnWW | Jul 04, 2009 03:03pm | #10

   It may be unusual but it is hard to come up with a better explanation, and it is quite possible that SC could have gotten stuck with a truckload of bad motors, so the replacements aren't any better than the originals. Quality control in Asia is still pretty lax.Another point, if there were serious voltage problems, a lot of equipment in your home would be having problems especially the electronics.John White

1. 
   okahun | Jul 05, 2009 01:10am | #14

   No problems with any other equipment on 240 or 120. This motor was replaced last fall about a month after I got the saw. If they had a bad shipment then it may be all gone by now. This motor howls worst than the original. As soon as I'm able I'll give Steel city a call back and get another motor. Thanks for your help John.

   okahun

6. 
   BrianDerr | Jul 04, 2009 09:39am | #7

   The voltage will be a little less when the motor is actually running, but not 15 volts.

1. 
   BrianDerr | Jul 04, 2009 09:45am | #8

   I have a question for everyone--what about voltages on the lower end? What can 240 and 120v motors tolerate? Is it 220 and 110? Brian

1. 
   davcefai | Jul 04, 2009 11:51am | #9

   In theory -10% so a little less than you state. In practice, you will feel that the tool is underpowered. It will tend to heat up more because you will tend to overload it and the cooling fan is running less efficiently.It may be counter-intuitive but you are much safer with over than under voltage.I have run an electric hand plane at 315V for a few minutes. Fortunately I stopped when I slowly realised that it seemed to be making a tremendous racket and there was a fireworks display inside the casing.It was a supply problem. When I phoned the local utility office the chap said "Yes, we know. We're fixing it. Send us the bills."

1. 
   BrianDerr | Jul 04, 2009 06:50pm | #11

   Thanks for the response. In my area it seems like the ambient voltage is 118-120 during the day. The 'new' shop (a major remodelling project) is about 100' from the house and I'm just looking at controlling voltage drop as much as I can to make it a good home for some new equipement.Brian

1. 
   davcefai | Jul 04, 2009 07:06pm | #12

   One assumes that you have made this type of calculation:http://nooutage.com/vdrop.htm

2. 
   BrianDerr | Jul 05, 2009 01:55am | #16

   That's a neat calculator, a lot more fun than interpreting charts in tiny print. Thanks.Brian

2. 
   okahun | Jul 05, 2009 01:02am | #13

   So your saying the rms volts will be a little less than the reading I got, ok thanks.

   okahun

1. 
   BrianDerr | Jul 05, 2009 01:44am | #15

   No not the rms, it's voltage drop which only occures while there's the load of the TS operation on the circuit. Brian

2. 
   JohnWW | Jul 05, 2009 03:49pm | #17

   okahun,I"m not enough of an electrical nerd to know exactly how the reading on an RMS meter differs from a simpler meter, but I have repeatedly read that you need an RMS meter to get an accurate reading of voltage.John W.

1. 
   Shoemaker1 | Jul 05, 2009 07:02pm | #18

   Leslie Nielson is who you were thinking of.
   Every one is worried about power surges. It is the Brown outs (low voltage) that kills tools appliances and computers.
   I live on a rural line. I have a UPS for my computer. When it senses low voltage it lets out a beep and with in 10's/sec it jumps to battery power.It is amazing how often that" beep" happens during strong winds, wet snow, and the odd idiot running into power poles. These beeps happen even though you can not see dimming of lights, TV distortion, etc.

1. 
   Carya | Jul 06, 2009 05:08am | #20

   Surges are the enemy of electronics. That's no myth. I would be surprised if brownouts damage motor-based appliances, but they sure annoy computers -- usually just temporarily.Its the continuous operation at lower line voltage that damages motors. That is why using low (large) guage extension cords (12 or 14ga) is important for power tools, if you have to use them.Operating computers at lower line voltage probably will not damage them, but they may not operate below about 95v. I saw a whole office building operate at 90v (equivalent at the 120v receptacles). Some computers (IBM) continued to operate, the rest failed to start. All were OK after the utility installed a new transformer on the pole.Andy

2. 
   Carya | Jul 06, 2009 04:56am | #19

   John,RMS meters accurately measure an integration of the voltage of any alternating current waveform. Non-RMS meters are calibrated to measure AC waveforms that are purely sinusoidal. The non-RMS meter should be within stated accuracy measuring line voltages in this case. (Usually +/- 3% for cheaper meters.)The exception for mains-related measurements is when there is noise or the waveform is distorted (modified). In non mains-related measurements, only RMS meters are accurate for different waveforms (triangular, square, etc) or perhaps very different frequencies.Andy

1. 
   JohnWW | Jul 06, 2009 06:15pm | #21

   Andy,Thanks for explaining this. Just to be clear; a regular volt/ammeter, I prefer the the old fashioned needle type to a digital, will give me a reasonably accurate reading of household AC?John W.

2. 
   Carya | Jul 07, 2009 03:31am | #22

   John,That is correct, but I will still chide you and Cheap Trick for using magnets to do a job best left for a computer. ;) (They are releasing the first album on eight track in 25 years.)Andy