New SS

[Ek1050]

So I refurbed an old 10ER a few months back (brand new to the "sport") and I think I caught something infectious in the process. I go to the Doc and he tells me I have the SS bug...

Fast forward a few months and what starts off as an fun and innocent family vacation to San Diego for a week turns into a SS purchase and delivery trip - I just can't leave CL alone. Long story short I have a Mark V I picked up for a good price and it's in great shape. Runs well, no rust. Basics are all there.

Anyhoo - I've finished breaking in the lathe and go explorIng with the table saw and higher speed setting. It works fine at first and now it won't stop popping the breaker on the outlet (the actual circuit breaker on the panel does not pop; just on the outlet).

I tried briefly to search the forums for possible causes but nothing immediately turned up. There are no major appliances running in the house and I cannot figure out why this machine would be drawing so much power that it would pop the breaker after working fine previously. I'm far from an electrician so I'm wondering if anyone can tell me if they think this might be an electrical problem or a machine problem.

I wish my iPhone could upload photos because the one of the SS strapped into the bed of my truck alongside all of the luggage is a sight.

Thanks for any info you can provide.

-Mike

[BuckeyeDennis]

Mike, I suspect that the "circuit breaker" on your outlet is actually a ground-fault circuit interrupter. Those don't trip because of high current, in the normal sense, they are designed to protect you from being shocked. They measure how much current is flowing from the hot wire to protective-earth ground (the third-prong safety ground), and open the circuit if that "leakage current" exceeds about five milliamps. Such as would happen if you had an insulation failure, and the hot wire shorted to the machine chassis.

The wire insulation on these old machines can get dry and brittle over time. For starters, you should inspect for cracked or missing insulation, and also for any loose strands of wire at the connection points.

[wa2crk]

If you can, look at the wires from the switch to the motor. If they look like these it could be part of the problem by having current leaking from the AC to the protective ground. They must be replaced

old wiring.jpg (80.35 KiB) Viewed 21588 times

Bill V

[beeg]

When was the last time ya oiled the sheaves? You also may have to replace the GFCI plug with a better quality one.

[Ek1050]

She's clean and lubed, wiring looks almost like new.
It seems the weight of the SS saw blade was overloading the machine.
I pulled the blade off and it runs fine. Any other ideas?

[br549]

Others have already posted suggestions and questions, but I'm not finding answers to all of the previous questions.

To recap, as I understand it:
1. GFCI Circuit is "popping", not main circuit breaker.
2. Problem was initially at higher speed (Table Saw function), UNLESS blade is removed. [DELETED REFERENCE TO BANDSAW]
3. Wires appear good, and everything is lubed.

Comments:
1. Have you tried running on non-GFCI protected circuit? A weak or faulty GFCI receptacle could be the problem.
2. [DELETED REFERENCE TO BANDSAW]
3. Starting while in higher speed ranges is not recommended. Many of us will leave it set on Table Saw speed (such as R) between cuts, and not dial down the speed before turning off machine between cuts, and that should be OK. However, before changing accessories or functions, it should be dialed down to at least the speed of the next use, if not slower.

EDIT: DELETED ERRONIOUS REFERENCES TO BAND SAW

[ChrisNeilan]

Others have already posted suggestions and questions, but I'm not finding answers to all of the previous questions.

To recap, as I understand it:
1. GFCI Circuit is "popping", not main circuit breaker.
2. Problem was initially at higher speed (Table Saw function), but now it also occurs when using Bandsaw, UNLESS blade is removed from bandsaw.
3. Wires appear good, and everything is lubed.

Comments:
1. Have you tried running on non-GFCI protected circuit? A weak or faulty GFCI receptacle could be the problem.
2. You are not leaving bandsaw connected while doing other operations (such as Table Saw) are you? I don't have a bandsaw, but Speed Chart indicates using it at lowest speed settings only (A, B, or C), depending on width of saw blade.
3. Starting while in higher speed ranges is not recommended. Many of us will leave it set on Table Saw speed (such as R) between cuts, and not dial down the speed before turning off machine between cuts, and that should be OK. However, before changing accessories or functions, it should be dialed down to at least the speed of the next use, if not slower.

No where in the post is there a mention of a bandsaw- It sounds to me like he is trying to start up on high speed, which could be problematic. I do it fairly often with no issue other than dimming lights a bit, but then again I have 20 amp circuits and 12 ga wire. I would loose the ground fault and replace with a good quality standard plug.

[br549]

No where in the post is there a mention of a bandsaw- It sounds to me like he is trying to start up on high speed, which could be problematic. I do it fairly often with no issue other than dimming lights a bit, but then again I have 20 amp circuits and 12 ga wire. I would loose the ground fault and replace with a good quality standard plug.

Color me red-faced ... mis-read it and do apologize for any added confusion.

[JPG]

A properly functioning GFCI should not trip unless there is an imbalance of current in the hot and neutral wires.

It is possible the start current is overloading the operating range of the GFCI to create an apparent difference in current.

[BuckeyeDennis]

A properly functioning GFCI should not trip unless there is an imbalance of current in the hot and neutral wires.

It is possible the start current is overloading the operating range of the GFCI to create an apparent difference in current.

I'm having similar thoughts. A 50A starting-current draw divided by a 5 milliamp trip threshold is a 10,000:1 ratio. So the GFCI needs an 80dB CMRR to avoid a nuisance trip. That's pretty high.

Without a saw blade installed, the starting-current surge is shorter. And the saw does spin up.

Is the speed dial set to slow, or is it at saw/joint? Setting it to slow (but only with the spindle turning!) will also reduce the surge duration.

I second the suggestion to try it with the machine plugged into a different branch circuit. A different randomly-chosen outlet might be wired downstream of the very same GFCI. Also, unless it is a dedicated circuit, leakage from some other device might be using up some of the available trip threshold.