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Forum topic by kennyd posted 05-13-2010 04:40 AM 1809 views 1 time favorited 14 replies Add to Favorites Watch
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kennyd

99 posts in 1655 days


05-13-2010 04:40 AM

Hi LJs,

I just got my Unisaw hooked up and made my first cuts in some 3/4” plywood with it. Unfortunately, when I put a load on the saw the blade slows down to almost a stop. I have a new sub-panel with 2 – 220 circuits in it. The new wire is 12/3 and the breakers are double pole 20 amps. Also, it seems a little slow getting up to speed when I first start it. Any ideas?

BTW, the wiring diagram for the motor says 230 volts, single phase. Does it make a difference that it’s on a 220 volt circuit?

Thanks in advance…

-- Kenny... The man who needs a tool he doesn't have is already paying for it.


14 replies so far

View closetguy's profile

closetguy

744 posts in 2547 days


#1 posted 05-13-2010 04:59 AM

First check to see that you actually have 220 at the outlet. Make sure both 110 legs are there with respect to the neutral (ground), and make sure they match on the plug to the saw. It is possible to have one of the 110 legs crossed with the neutral and the saw only receiving 110.

-- I don't make mistakes, only design changes....www.dgmwoodworks.com

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TopamaxSurvivor

14750 posts in 2331 days


#2 posted 05-13-2010 06:02 AM

Sounds like a voltage drop problem to me. Wires between the transformer and the saw are too small to carry the load.

-- "some old things are lovely, warm still with life ... of the forgotten men who made them." - D.H. Lawrence

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TopamaxSurvivor

14750 posts in 2331 days


#3 posted 05-13-2010 06:03 AM

BTW, 220,230, 240 are all terms for the same single phase connection.

-- "some old things are lovely, warm still with life ... of the forgotten men who made them." - D.H. Lawrence

View Cato's profile

Cato

641 posts in 1968 days


#4 posted 05-13-2010 12:56 PM

Might have to run 10/3 to the plug from the subpanel if the run has some length to it, as Topamax points out the 12/3 could be to small for the length of run and cause voltage drop.

That is assuming as Closetguy points out that you have it wired correctly.

View JAGWAH's profile

JAGWAH

929 posts in 1739 days


#5 posted 05-13-2010 01:50 PM

All good advice you are loosing power. 10/3 sounds right.

-- ~Just A Guy With A Hammer~

View kennyd's profile

kennyd

99 posts in 1655 days


#6 posted 05-13-2010 06:55 PM

Hi Everyone,

Thank you for all the responses. I’ll have the electrician come back and take a look for me. I’m not comfortable fooling around with electricity. I hope it’s something as simple as heavier wire as I can just take the OSB boards off of the shop walls in the area of the wiring. Shouldn’t be too much trouble.

-- Kenny... The man who needs a tool he doesn't have is already paying for it.

View Brad_Nailor's profile

Brad_Nailor

2531 posts in 2612 days


#7 posted 05-13-2010 07:19 PM

Ya it sounds like you don’t have the proper voltage. My Unisaw jumps up to full speed in milliseconds….and never bogs down no matter what I push through it..

-- http://www.facebook.com/pages/DSO-Designs/297237806954248

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Stargazer

49 posts in 1595 days


#8 posted 05-14-2010 03:04 PM

Ditto what Brad said, plus I run my Unisaw (3hp) off 50’ of 10/2 UF cable plugged into our dryer outlet. No problems whatsoever.

Rick

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Brad_Nailor

2531 posts in 2612 days


#9 posted 05-15-2010 05:06 PM

HA! Rick..I have the exact same saw and I do the EXACT same thing..I made a hillbilly extension cord from a 50’ piece of 10/2 with a dryer plug on one end! Thats funny…

-- http://www.facebook.com/pages/DSO-Designs/297237806954248

View jussdandy's profile

jussdandy

157 posts in 1862 days


#10 posted 05-15-2010 06:40 PM

not gonna disagree with anything ya done been told, just one more thing to check, If ya have the magnetic switch take the black cover off, behind it is a dial with numbers on it, some times you have to adjust this dial to the lowest number that your saw will work with, I dont know all the details but you are basically adjusting the amps to the saw, it needs more amps to start, less to run, just for your info I have 3hp, single phase and run a double pole 15 with no problems.

-- Randy I have the right to remain silent, just not the ability ; )

View uffitze's profile

uffitze

199 posts in 1610 days


#11 posted 05-15-2010 07:12 PM

voltage drop is rarely a problem in a home or shop, but if you think that it might be, a google search will give you a couple of online calculators that you can use.

View kennyd's profile

kennyd

99 posts in 1655 days


#12 posted 05-16-2010 03:20 PM

UPDATE: Had the electrician back to check the wiring to the saw. The panel, the plug, and all of the outlets are wired correctly. We then ran the saw without a load on it while he used an amp meter on the wires and found that we’re getting 4.2 amps on one side and 2.2 amps on the other. Did it again under a load (ripping a 2×4) and the draw jumped up to almost 17 amps. The saw bogged down at that point. I then took the saw apart to get to the motor plate to make absolutely sure which motor was in it and found it is indeed the original 1 1/2 hp single phase 240v Baldor motor. The electirician feels that the motor may have a bad winding and that one side is compensating for the weaker side. Does this make sense to anyone? I’d hate to have to get a new motor for it. Almost $400.00!

-- Kenny... The man who needs a tool he doesn't have is already paying for it.

View Binn's profile

Binn

86 posts in 1609 days


#13 posted 05-16-2010 03:44 PM

I had a simular problem with my Laguna Pro series panel saw. It would do the same thing so I shipped it back to Laguna and got my refund (long story,see my review; You don’t get what you paid for! ). The Laguna saw had to many issues other than electrical so I did not bother getting an electrician, but it was plugged in the same outlet as my Grizzley was. The Laguna saw was made in China.

-- Barry, Louisiana

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TopamaxSurvivor

14750 posts in 2331 days


#14 posted 05-17-2010 01:52 AM

Sounds like a motor problem. There is no way a motor can run with twice as much current on one leg as the other.

If you have a motor starter with dial;s in it to adjust the amps, it will not give the motor more amps is you turn it up. It either trips or doesn’t. Properly ad justed, it should just let the motor run a full load. If you turn it way up, you take a chance of burning the motor out.

-- "some old things are lovely, warm still with life ... of the forgotten men who made them." - D.H. Lawrence

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