LumberJocks

Table saw short

  • Advertise with us

« back to Power Tools, Hardware and Accessories forum

Forum topic by Ryan_81 posted 12-29-2018 12:33 AM 882 views 0 times favorited 36 replies Add to Favorites Watch
View Ryan_81's profile

Ryan_81

8 posts in 143 days


12-29-2018 12:33 AM

Topic tags/keywords: table saw trip breaker

I have an older 10” contractor table saw that used to work until it was moved to a new house. The toggle switch broke and I replaced it, but it only trips when I flip the switch. I’ve tried more than one circuit. It’s plugged into a 20 amp circuit (it was on a 15 preciously). The blade turns. From talking with others with woodwork experience, they’ve all agreed I probably have a short. I took the motor off and don’t know where to go from here. I have an analog volt meter, but I don’t know what to do. I’d like to save the saw as it’s in good shape and I’d rather not buy a new one. Thanks!


36 replies so far

View JohnMcClure's profile

JohnMcClure

618 posts in 999 days


#1 posted 12-29-2018 12:45 AM

There should be a starting capacitor on the side of the motor. It would be underneath an easy-to-remove housing atop the motor body like this one:

That’s the most common point of failure, so try replacing it first if you can’t get anyone qualified to help with further diagnostics.
How many HP is the motor?

-- I'd rather be a hammer than a nail

View JohnMcClure's profile

JohnMcClure

618 posts in 999 days


#2 posted 12-29-2018 12:47 AM

Can you elaborate on the statement “It only trips when I flip the switch… the blade turns”
Are you saying that, when it is plugged in to the wall with the switch off, then you turn the switch on, the blade turns a little bit and then the circuit breaker trips?
Or are you saying that when you turn the switch on, there is a clicking sound and the switch releases without starting the motor at all?
Or something else?

-- I'd rather be a hammer than a nail

View woodbutcherbynight's profile

woodbutcherbynight

5964 posts in 2768 days


#3 posted 12-29-2018 03:10 AM

What kind of toggle switch did you use? I have a original one from same saw. They are much heavier duty than what you typically find at local retailers.

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

View ibewjon's profile

ibewjon

361 posts in 3152 days


#4 posted 12-29-2018 03:11 AM

Do you mean the blade turns by hand with the power off? If it trips immeadiately, you could have a bad switch, or it could be wired wrong creating a short when the switch is turned on. Disconnect load side ( outgoing ) wires from switch and try it again. If it trips, it is not the motor. Do you have a two pole switch, four screws plus a ground, or a single pole, two screws plus the ground? A two pole switch if wired wrong is a direct short. If the switch is good, move to the cord to the motor next, disconnecting at the motor and capping the ends for safety. Work through one part at a time. Moving the saw could have finished wearing through a worn spot in the cord. Overtightened cord connectors can do this.

View MSquared's profile

MSquared

422 posts in 273 days


#5 posted 12-29-2018 03:35 AM

Any humming or clicking at the motor at turn-on? If so, ‘typically’ start capacitor. Just swapped out the one on my compressor. Worked just fine for ten years and then ‘poof’!

-- Marty, Long Island, NY

View ToughCut's profile

ToughCut

65 posts in 1966 days


#6 posted 12-29-2018 04:22 AM

I think there is a good chance you wired the new switch wrong and it shorst out the circuit when you flip the switch, check the wiring to the switch.

-- If you are not willing to learn, No one can help you. If you are determined to learn, No one can stop you.

View MrUnix's profile

MrUnix

7357 posts in 2558 days


#7 posted 12-29-2018 05:09 AM

The toggle switch broke and I replaced it, but it only trips when I flip the switch
- Ryan_81

If the only thing that changed was a new switch, then you wired it wrong.

Cheers,
Brad

-- Brad in FL - In Dog I trust... everything else is questionable

View MSquared's profile

MSquared

422 posts in 273 days


#8 posted 12-29-2018 05:55 AM

Ah! Missed that switch replacement detail! Yep. Start there for sure. I always ask myself’ ‘what’s different about this (whatever it is) since it was last working just fine’ and Bingo!

-- Marty, Long Island, NY

View Ryan_81's profile

Ryan_81

8 posts in 143 days


#9 posted 12-29-2018 05:57 AM

Thanks for the responses! I’ll go in order.
1. Where can I get a new capacitor? The saw is 1 1/2 hp.
2. When there’s no power, I can rotate the blade. The instant I turn it on, the breaker trips. Nothing happens to the motor when I turn it on.
3. I took the old switch to a nuts and bolts shop to get a replacement. I wired the new one exactly the way the old one was. It tripped the breaker, so

I switched the wiring just to make sure. Same results.
4. The motor doesn’t hum or make any sounds. The breaker trips the instant I turn it on.

View MSquared's profile

MSquared

422 posts in 273 days


#10 posted 12-29-2018 06:25 AM

Ohm-out the wires for Continuity? Check Brushes? Hard to say without putting an eyeball to it. Capacitor can probably be had from EParts Direct. But, no Hum. Hmm? Capacitors can usually be identified as bad by bulging at the connector lug end. May be a slim chance you got a bad replacement switch. Any burnt smell anywhere? Signs of burning? Shorting out against a metal mounting bracket? What’s previously been suggested are the usual suspects. Maybe try isolating the wire mounting lugs, at the switch and motor, from each other to prevent arcing? .....Bigger Hammer?! I joke, but it’s a real PITA!

-- Marty, Long Island, NY

View mrg's profile

mrg

860 posts in 3358 days


#11 posted 12-29-2018 02:00 PM

Sounds like you wired the switch wrong. I did that on my saw when I swapped a switch. Check the insulation on the wires, if you have a slit it can be arching.

-- mrg

View Phil Soper's profile

Phil Soper

25 posts in 160 days


#12 posted 12-29-2018 03:37 PM

Sounds like your supplier did not give you an exact replacement – The new switch will need to be wired differently to work correctly. I photo showing the wire colors connected to the switch will help. A closeup of the switch showing the make and model will also help

View Mike_D_S's profile

Mike_D_S

595 posts in 2574 days


#13 posted 12-29-2018 03:40 PM

It may not be likely with a brand new switch, bit it could be a bad switch.

1. Label the wires and disconnect the switch.
2. Use your meter across all four connectors on the switch in different combinations until you can tell for sure which ones are connected/disconnected to which with the switch on/off and which ones are never connected to each other.
3. If not obvious, use the meter to verify which two wires come from the plug and make sure they aren’t being connected to the switch so they short to each other when the switch is thrown.

If you can’t figure out which connectors are linked when the switch is thrown or they all seem to be linked together no matter what the switch position is, then I’d replace the switch.

Mike

-- No honey, that's not new, I've had that forever......

View Mike_D_S's profile

Mike_D_S

595 posts in 2574 days


#14 posted 12-29-2018 03:49 PM

One more question, the way that switch is wired makes me wonder, do you have it wired for 110 or 220?

Mike

-- No honey, that's not new, I've had that forever......

View JohnMcClure's profile

JohnMcClure

618 posts in 999 days


#15 posted 12-29-2018 04:39 PM

As others have said, based on the additional information you gave, almost certainly the switch is wired wrong. Forget the capacitor stuff, the motor would hum.
Get someone familiar with motors to wire it correctly and safely.

-- I'd rather be a hammer than a nail

showing 1 through 15 of 36 replies

Have your say...

You must be signed in to reply.

DISCLAIMER: Any posts on LJ are posted by individuals acting in their own right and do not necessarily reflect the views of LJ. LJ will not be held liable for the actions of any user.

Latest Projects | Latest Blog Entries | Latest Forum Topics

HomeRefurbers.com