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I just got a new 1 1/2 horse power table saw. When i turn it on it dims my lights when it get turning it seems ok. Is this common with normal home garage power.
 

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Not knowing that much about electricity - but I think your motor is drawing more amps than what your system is allowing. In other words - the motor when powering up - is drawing the power and taking it away from your light until it reaches full power. I bet money if you turned on another tool at the same time, you would flip the breaker. You need to put the motor on a dedicated outlet. (I guess?)
 

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Not knowing that much about electricity - but I think your motor is drawing more amps than what your system is allowing. In other words - the motor when powering up - is drawing the power and taking it away from your light until it reaches full power. I bet money if you turned on another tool at the same time, you would flip the breaker. You need to put the motor on a dedicated outlet. (I guess?)
This is right on the money, you have to put in a dedicated circuit. It is not good for the motor because it's starving for power and will burn out before its time. If it's in the garage you may want to do a little investigating to see if you have another plug on a different circuit and see whats all on that one.sometimes it happens to be one that hardly anything is on it. One thing you need to do is look at the motor and it will have a tag that states the amps you need.
Let us know what you find out here.
By the way welcome to the forum KKnight
 

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It sounds like you start the saw and see the lights dim. This should be momentary. On your motor there should be an amp rating. Sometimes there are two. One is FLA "Full Load Amps" and is the maximum draw with the motor under a heavy load. If the other one is there it may say LRA "Locked Rotor Amps." LRA is the amperage a motor draws on start up. This is usually about 6 times the running amps and actually only last a fraction of a second. If your lights are returning to normal after start up, this is normal and is of no concern. This is why electric motors require slow blow fuses or breakers with a delay. Household breakers have a delay. Running a dedicated circuit may help depending upon the feed. Quite frankly, it may not. If the lights do not return to normal, your circuit is marginal and should be addressed. If you have an AC volt meter, you can check the open circuit voltage and then the closed circuit voltage. A drop in excess of 10% is a problem.

Tom
 

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I have the same problem in my garage, when i turn on my 1 1/2 HP table saw, the lights dim almost off for a half a second and then come right back. The same thing happens when my compressor kicks on. Good thing I won't ever need to run them at the same time.
 

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You need to add a circuit for your saw, look in the panel box if have empty spot add a breaker and run a new line. Any large amp pulling equip. should on there own circuit. In time the breaker will get weak and could cause the wiring to over heat. It is dimming the lights because it is at it's limited before tripping.
 

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The lights dimming has nothing to do with the circuit breaker. It has to do with the voltage drop caused by the large amp draw at start up. While it is a good idea to have separate circuits for each heavy load, adding a separate circuit may not fix the problem. Many old houses were fed with a 60 amp circuit and the drop wire coming to the house is small. If your shop is in a garage with a sub panel fed with a #10 wire, running another circuit to that box will not alleviate the voltage drop between the main and sub panels when the motor starts. If the house has a 150 amp main circuit then running directly to the box should resolve the problem. If the house is only feeding the shop with a 20 or 30 amp circuit, it really doesn't matter how good the circuit into the house is you will still see a voltage drop in the shop feed, especially if it is a long run. In this case running back to the house main panel would be the answer. The contact in a breaker is fully closed until the trip point is reached. At this time the breaker snaps open. Breakers can go bad. Nuisance tripping, where the breaker trips before its rating, and failure to reset are probably the most common breaker failure.

Tom
 

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Tom, You sound like an electrician? It never hurts to have a dedicated circuit for something that draws more than 8-10 amps. But like Tom say's that won't necessarily fix your problem. I wouldn't go so far as to say it won't fix it. Our tools only run for a few seconds at a time, maybe a few minutes. Something like a dust collector, or an air comperssor that runs a lot should be on it's own. A slight dim isn't a big deal. If your lights are going half off, that's not good. I would look into that. Check your connections. Something could be loose. I was running my whole shop, 10 power tools plus hand tools on one 15 amp breaker. What finally did me in was the about the 10 th light. My garage lights were on the same circuit. Once I got off my butt. I ran 4 new circuits. If you can afford it. It's not a bad idea to put your big draw tools on there own.
 

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Basically, if you have an adequate main panel, and adequate main breaker, running a dedicated circuit directly from your panel to an outlet for your saw, should cure the problem. At one and one and one half HP you might want to put in a 20 amp circuit, and outlet, instead of a 15 amp circuit. [Check to see if your wire is adequate for 20 amps] If you have more open slots in your main panel you might also consider running some additional circuits at the same time. This will give you a little more flexibility for expansion.

My 11/2 Hp table saw also dims the lights, because all of the lights in my woodworking shop are tied into one 15 amp circuit, along with the outlets. The original structure was a warehouse, and the wiring was never planned for a workshop. I have lots of power avilable, and lots of open breaker slots, I just have to decide how many more circuits to run, and get off my butt and do it.
Just to be on the safe side, and for insurance purposes, get a permit, and have the work inspected.

Gerry
 

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Tom, You sound like an electrician?
I'm an ex-HVAC mechanic and currently have a small business doing marine electrical work. I certainly have a lot to learn, but do have a fair understanding of what it takes to get an electric motor running.

Tom
 

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I've been an electrician for about 26 years. One I've learned, I never say things like this will defiantly fix your problem. Or there's no way that will work. Electric is full of surprises. I did a job for a lady like 20 years ago. Her lights dimmed every time her furnace kicked on. It was a dedicated circuit. I told her she needed a bigger service. It didn't fix it. I blamed it on the power co. at that point.
 

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One I've learned, I never say things like this will defiantly fix your problem. Or there's no way that will work. Electric is full of surprises
Gota agree on this one, in my house my electric fireplace dimms the lites but not the microwave, my dust collector does but not my miter saw. I wonder if it has anything to do with how the power is distribuated in the panel. I always though till now in was a under powerd service Mine is 100 amp in a 1200sqft home
 

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Bigredc,

Your point is well taken. That is why I use words like may and should. I've been working on some form of electrical stuff for 42 years and you'll note that I said I still have much to learn. One definite I have learned is never to say "that can't happen."

Tom
 
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