Micro-switch on Italian Bandsaw

[David T Ross]

Not to get into all the details, but I bought a snazzy new bandsaw 4 months ago and the overload switch kept tripping and shutting of the motor. After crawling all over the machine and my shop wiring (following the distant distributors phone instructions) I finally put an amp meter on it and turns out the motor was pulling way too many amps, thus tripping the switch. So I get a new motor and main switch and rewire the whole thing and then the micro-switch on the lower door burns out. I've jumped the switch and the saw runs great. The distibutor said he hasn't had any problems with those switches before, the same thing he said about the motor, so I'm assuming the high amps the motor was pulling (25 on a 14.5 amp motor) burned up the switch, is that possible? I've been trying to get a replacement switch from him for almost two months (he again said it should ship this week). Is it reasonable to want to replace the switch on the other door since the same amps ran through it? Or maybe high amperage doesn't affect those switches and a just happened to get a saw with a rare bad motor and a rare bad switch? Anyone with any experience with these things?

[Peter Quinn]

I have no practical experience with such wiring, but I am curious as to the maker and distributer.

When a CS rep tells me they have not had problems with a given part before, I usually respond along the lines of "Well, lets hope not, otherwise you would be knowingly selling a defective product. Now lets move forward and fix the problem which has arisen."

[Dick Sylvan]

Not to get into all the details,

Why not? I'm curious what brand it is!!

[David T Ross]

It's an Agazzani B-20 sent out by Eagle Tools in Los Angeles. Overall they've been reasonable, they did finally send a good motor out. But even when we discovered that the origonal motor was getting +230v and was still pulling 25 instead of 14.5 amps they didn't believe they had sent a bad motor and had me take the motor off, direct wire it and plug it into various 240V outlets in my house (definitly not fun, probably not safe) before they would ship a different motor out. And that was after they suggested direct wiring the motor on the saw and running it for an hour or two to see if it heated up!!! I completely understand being thorough, but at some point...

[Ken Garlock]

Hi David, and welcome to the creek. Do jump in frequently, the water is not that deep.;)

Regarding the momentary push button switch on the lower cabinet door, that switch is most likely part of the same circuit that causes the electro magnet solenoid power switch to operate. Your switch in question does not carry the full load of the band saw motor. In years past, I would have recommended getting a spray can of ether, or di-cloro-di-floro-methane, aka freon, and spraying the switch throughly. Let suggest that you stop by your local radio-shack and picking up a spray can of contact cleaner. Unplug your saw and spray the switch a couple times. While you have the can in hand, spray the switch in the top cabinet.

[Tom Veatch]

... so I'm assuming the high amps the motor was pulling (25 on a 14.5 amp motor) burned up the switch, is that possible? ...

It all depends on how the saw is wired internally and what the current rating of the switch might be.

If the current through the motor also passed through the switch (not necessarily true) it could have exceeded the current rating of the switch and caused it to fail.

If the saw is equipped with a magnetic switch, the switch is probably wired in series with the relay coil. If so, the switch would not have seen the high current through the motor and would not have been affected by it.

[David T Ross]

Tom, I have a wiring diagram for the saw but can't tell what's what, it does have a "low-voltage coil" in there somewhere would that protect the switches? I don't know what the micro-switches are rated for but the overload switch is less than 16 amps.

[Charles Lent]

When an electric motor pulls almost twice it's rated current on a 240 volt circuit, I usually check to see if it is wired correctly, as a motor that is wired for 120 volts will draw about twice it's rated current if it is connected to a power source of 240 volts. It will likely burn up very quickly if you leave it running in this condition too.

If the micro switch is in series with the motor then it likely went bad due to the excess current that the motor was pulling. If it is wired in a control circuit where it supplies power to a power relay which then controls the power to the motor, then the motor problem could not have caused the switch to go bad.

Charley

[Dan Lautner]

David, Sorry to hear about your electric/ motor problem. I have dealt with Eagle tools a few times and I'm sure Jesse or Raul will take care of you. Please let us know how you like the saw once it is up and running. I have been eying that saw for a while now. Did you get the new B-20 with the increased resaw?

Dan

[David T Ross]

Charley, the wiring diagram for the saw shows a circuit for all the stops and switches coming off the main wires in between the terminal board and the overload cutout/motor. In other words from just after the main terminal board there seems to be two seperate curcuits (loops?), but no relay seperating them. Does that make sense, or mean anything? I should probably track down someone to look at the diagram, because I know what you're saying I just can't read electical diagrams.

For now I've jumped the bad switch and have been using the saw. Of course, it's amazing! I've been mostly re-sawing recycled Fir, but it hasn't slowed down on anything I've thrown at it. I don't know if it's the new model or not, the resaw is just over 13". I talked to Jesse last night and he said a new switch should ship today, like I said they've seemed pretty reasonable through out the process. I'm just wondering about damage to the other switches, but I suppose if they're working now...