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Mysterious problem with my house electricity vs variable speed sander

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Forum topic by jopo posted 01-05-2016 02:56 AM 4505 views 0 times favorited 79 replies Add to Favorites Watch
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jopo

17 posts in 703 days


01-05-2016 02:56 AM

This question might better be sent to an electrical forum but since I’m a lumberjock, I’ll try here first.

I just purchased a Makita BO5041 variable speed orbital sander. It says it goes as slow as 4000 opm’s and goes up to 12k opm’s. Although not an exciting purchase, I hadn’t had a “new” one in 10-12 years so I was hoping that buying a nice one would be an upgrade in user experience. I plugged it in and set the sander to it’s lowest speed (1) and the motor didn’t even move. It’s not until I turned the speed control to 2.5 that it got up to speed enough to even pretend to start sanding. I thought it was a bad sander so I brought it back to the store and showed the salesperson the problem. Of course…it worked fine at the store. I then figured that maybe my extension cord was long enough that it caused some voltage drop. I then went home and tried it directly into several of my outlets on various circuits and I was met with the same problem. At speed 1 the motor makes a quiet buzz and ever so slowly turns the pad but I’m talking virtually nothing. I then figured that maybe I made an error at the store so I took it back again ( this time to a different store so they wouldn’t recognize the fool). Once again it worked fine at the store. Exasperated I went home to test all the voltage of my outlets. All my outlets showed readings from 114 to 115 volts. I would assume that this is fine. I’ve read that 117 volts is actually the average but many houses vary a few points above and below that number and there’s no issue. I haven’t noticed any other problems with any electrical devices at my house. Does anyone have any idea?
If I was certain that the motor is getting up to it’s full speed at 5 and the 4k speed was somewhere in between, I’d be fine with the tool but with the way its acting, I’m worried that I’m not getting anywhere near the full speed.
Thanks
jared


79 replies so far

View tomd's profile

tomd

2027 posts in 3238 days


#1 posted 01-05-2016 02:44 AM

Many ROS sanders have to be applied to a surface before they engage. If your holding it and not applying it, it may not spin even at low speed.

-- Tom D

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jopo

17 posts in 703 days


#2 posted 01-05-2016 03:34 AM

I doubted that was the case with mine but I just checked to be sure. Nope. That’s not the problem but thanks for the effort. Still boggling the mind but then again, my knowledge of electricity is pretty poor.

View builtinbkyn's profile

builtinbkyn

651 posts in 408 days


#3 posted 01-05-2016 03:38 AM

Have you tried using a different outlet on a different circuit?

-- Bill, Yo!......in Brooklyn :)

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MrUnix

4247 posts in 1667 days


#4 posted 01-05-2016 03:41 AM

Have you tried using a different outlet on a different circuit?
- builtinbkyn

LOL – since he said in the original post ”I then went home and tried it directly into several of my outlets on various circuits and I was met with the same problem.”, I’m guessing that isn’t the problem :)

Cheers,
Brad

-- Brad in FL - To be old and wise, you must first be young and stupid

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builtinbkyn

651 posts in 408 days


#5 posted 01-05-2016 03:42 AM

Guess I missed that part LOL


Have you tried using a different outlet on a different circuit?
- builtinbkyn

LOL – since he said in the original post ”I then went home and tried it directly into several of my outlets on various circuits and I was met with the same problem.”, I m guessing that isn t the problem :)

Cheers,
Brad

- MrUnix


-- Bill, Yo!......in Brooklyn :)

View woodbutcherbynight's profile

woodbutcherbynight

2465 posts in 1877 days


#6 posted 01-05-2016 04:02 AM

Ask your neighbor to use his outlet and see what it does. If they have same issue then I would suspect the utility company might have an issue. If not, then you might want to have your box checked. You may have stumbled onto something that needs to be addressed.

-- Live to tell the stories, they sound better that way.

View clin's profile

clin

514 posts in 464 days


#7 posted 01-05-2016 04:17 AM

Try this.

Run the sander, but also check the voltage at the same time. For example, if you plug into a typical socket with two outlets, test the voltage in the empty socket while running the sander and see if it still reads about 115 Vac.

If the voltage drops a significant amount (> 1 V?) , there is some sort of wiring problem. Since you said the problem was on various circuits, then a single bad circuit must not be the issue.

But lets make sure your definition of a circuit is the same as mine. In this context, separate circuits mean separate circuit breakers. It’s really hard to image a poor connection affecting multiple circuits. I would think you would have seen much more serious issues by now with big loads, like your furnace or AC (or table saw).

If it turns out the problem is just on one circuit, maybe there is just a single poor connection on that circuit. Keep in mind that outlets get daisy-chained together so the last outlet, at the end of the circuit, has connections at every other outlet.

Another possibility is a bad breaker or GFI.

Not knowing anything about your new sander, I can only speculate. But, perhaps your house wiring has a grounding problem that affects the sander. I really can’t see this happening as the ground should only be there for safety and I don’t think the sander should be using it for anything other than grounding the tool case. But who knows, maybe something to look at.

This does sound very weird. But I wouldn’t ignore it. It could just be that this sander is the canary in your coal mine and is the symptom of a significant wiring issue.

Any chance your house uses aluminum wire. The connections on aluminum wire go bad. It’s a significant fire hazard. It can be dealt with without rewiring your house. Just requires adding copper pigtails to all the aluminum in the appropriate way.

-- Clin

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jopo

17 posts in 703 days


#8 posted 01-05-2016 04:58 AM

Thanks guys.
Woodbutcher, I’ll hopefully be able to get one of the neighbors to let me plug it in this week. I was curious about this as well.

Clin. I just tried the test you suggested with the two sockets. At the lowest “1” setting, I saw only about .1 or possibly .2 voltage drop. It was hard to get a precise number as the mulitmeter is moving a few decimals constantly. At the full speed “5” setting the voltage drops about 1 whole volt.
Yeah I was thinking of a circuit the same as you. Each circuit has a variety of loads but it’s own breaker.
I did try a variety of circuits in my house, some being GFCI and some not.
Aluminum wire…nah I’m pretty sure it’s all copper.
Since my house was built in 1951 and much of the electrical at some point goes through original wire, there’s a lot of receptacles that didn’t ever have a ground wire and I’d install one in my crawl space to a cold water pipe. But that said,the sander doesn’t have a ground plug but just the common 2 wire polarized plug.

  • Coincidently I’m looking to install a GFCI receptacle just under my outdoor circuit panel on it’s own 20 amp circuit. Hopefully I can get this receptacle working this weekend or the next as it’ll be a great test for this sander. I’m just hoping I figure it out quickly…before the store return date.

The mystery continues….

View TheFridge's profile

TheFridge

5765 posts in 954 days


#9 posted 01-05-2016 05:04 AM

Ghosts

-- Shooting down the walls of heartache. Bang bang. I am. The warrior.

View clin's profile

clin

514 posts in 464 days


#10 posted 01-05-2016 06:01 AM

I’m not surprised by anything you’ve said. A 1 V drop is not enough to be the issue. And I agree that since the sander doesn’t use the ground connection, a grounding problem would seem to be unable to affect the sander.

Also, the small voltage drop means that a poor connection isn’t your problem. So possible sources of a poor connection (like aluminum wire) don’t matter.

Maybe it’s time to think of something else that is different between your house and the store. For example, was there some reason the sander was much colder or warmer at one location than another.

I noticed this in the Makita web site:

“Pad control system for controlled pad speed upon start-up”

I could see any mention of this in the manual.

I know that tomd already mentioned something that likely refers to this. But it sounds like it is worth revisiting.

Just look at every little detail of what you are doing different at home vs the store. For example, maybe you took the sanding disk off at the store. That type of thing. Don’t consider why something couldn’t possibly make a difference. Just try to figure out what is different. Something has to be different. Once you identify that, then perhaps you can figure it out.

I’m leaning away form this being an electrical wiring problem based on what you’ve said. It’s a weird one, but there is an explanation.

-- Clin

View DylanC's profile

DylanC

196 posts in 2142 days


#11 posted 01-05-2016 06:32 AM

I, too, am no expert but I’ll throw. In my 2 cents.

If I understand correctly, variable speed AC-powered tools convert power to DC using a rectifier (diodes) and a DC motor. Speed is adjusted by using a potentiometer (variable resistor) to vary the voltage and current supplied to the motor.

Maybe the lack of a 3-wire electrical circuit (HOT-NEU-GND) is somehow effecting the tools rectifier? Maybe only rectifying half of the wave form? Not sure how that could happen, though. And if you’ve got some newer outlets with a ground, that should eliminate whatever problem that would’ve caused. Do you have any other variable speed tools (corded drill or router) that work fine?

I would maybe wire up a temporary 3-wire receptacle right off the panel and see what happens.

-- Dylan C ...Seems like all ever I make is sawdust...

View TinWhiskers's profile

TinWhiskers

179 posts in 420 days


#12 posted 01-05-2016 06:32 AM

A better check of the voltage coming into your home? Could one of the hots from the pole be shorting?

View MrUnix's profile

MrUnix

4247 posts in 1667 days


#13 posted 01-05-2016 06:38 AM

I would maybe wire up a temporary 3-wire receptacle right off the panel and see what happens.
[...]
Maybe the lack of a 3-wire electrical circuit (HOT-NEU-GND) is somehow effecting the tools rectifier?

It’s double insulated, so there is no ground on the plug… even if the outlet had one it wouldn’t do any good.

Cheers,
Brad

-- Brad in FL - To be old and wise, you must first be young and stupid

View EEngineer's profile

EEngineer

1061 posts in 3081 days


#14 posted 01-05-2016 11:47 AM

If I understand correctly, variable speed AC-powered tools convert power to DC using a rectifier (diodes) and a DC motor. Speed is adjusted by using a potentiometer (variable resistor) to vary the voltage and current supplied to the motor.

Almost certainly not. These devices tend to use a universal motor (brushes are a sign of this) and a triac chopping circuit similar to dimmer controls for incandescent bulbs.

One thing I haven’t heard anyone mention yet is arc-fault detection circuit breakers. AFCI breakers are problematic with any brush motors. Do you have a circuit breaker box and has it been upgraded since the house was built in 1951? Then you might have AFCI breakers installed. Now these are different from GFI – GFI’s don’t tend to cause problems with brush motors or these kind of speed controls.

In my experience, the AFCI just tended to trip with brush motors, not screw up the AC waveform. But I have not looked into the circuitry they use for arc fault detection. I just mention this as a possibility.

-- "Find out what you cannot do and then go do it!"

View Gene Howe's profile

Gene Howe

8264 posts in 2896 days


#15 posted 01-05-2016 01:25 PM

What was your experience with the neighbor’s outlets?

-- Gene 'The true soldier fights not because he hates what is in front of him, but because he loves what is behind him.' G. K. Chesterton

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