[OP]
Contributor
I found a motor protection circuit breaker designed just for this purpose. I assume this is what you were looking for. Seems like this would be the ideal kind of device, something designed for motors that is. It has an adjustable dial.Originally Posted by Erik Loza
s-l640.jpeg
Contributor
I think we're getting two different things confused:
The Siemens breaker you have in your breaker panel is intended to protect the wiring between the breaker and the receptacle. Not the saw motor. Think about all the other circuits in your house: you have an outlet in your bathroom that you plug your electric toothbrush in to - do you need to go change the breaker on that circuit to a 0.12A breaker to match the label on the toothbrush? Of course not. The 15A breaker on that circuit is sized to protect the 14AWG wire feeding the outlet. Should your electric toothbrush develop a short circuit, it may start on fire, but the 15A breaker will trip before the 14AWG wiring in your walls gets hot enough to start a fire. Protecting the wiring feeding a receptacle is the purpose of a breaker. An appliance plugged into that receptacle needs its own protection.
The "motor protection circuit breaker" you linked a picture of - there is one of those in your saw, already. It may look different or be hidden somewhere in the starter enclosure, but there definitely is one. It is intended to protect the motor from over-current. It does not go in a load center (breaker box) - it goes in the enclosure on the piece of equipment that also contains the contactor.
You are tripping the Siemens breaker, so the setting of your saw's over-current protection device is not relevant (you are not tripping it).
You need both of these devices (the breaker and the motor over-current device) to protect different elements of the system.
[OP]
Contributor
Hi Dan,
Erick, as quoted, was talking about a breaker in the bandsaw itself with a dial for amperage that might have been tripping. I was just posting the picture of the same kind of breaker that would be inline between the motor and the panel. I was not suggesting it was a replacement for the breaker at the panel.
Derek
Contributor
Gotcha. Just to be clear - you do already have one of those in your saw.
Contributor
Yes, that's it. Again, I haven't worked on a ACM saw but all the Centauros had that as the main start contactor. Perhaps the ACM's are wired totally different? No idea. This seems like an inordinate amount of hassle for such a simple machine as a bandsaw.
Erik
Ex-SCM and Felder rep
[OP]
Contributor
I agree +100
Similar wiring with an Eaton cont actor, but no breaker/dial that I could see. Perhaps the magnetic switch is the breaker though.
Last edited by derek labian; 12-27-2021 at 10:56 AM.
Contributor
I’m recalling a damaged bell housing on that motor found while unpacking, and that you had to do some straightening to get it spinning freely. Any chance that the damage could have gone deeper than just the outer shell, and contributing to the current issue? Just thinking out loud.
earl
[OP]
Contributor
I thought that too, but the housing was only touching the plastic fan blades, and they seem (mostly) undamaged. It now spins freely (and so do the wheels) so I don't think thats the culprit. No other damage on the motor. Load is a constant 90A, but if it doesn't fall off to 22A or less once at full speed, I've got an issue.
Contributor
Derek, I'm looking at the operator's manual for our FB640, which I believe is the same machine as yours, and they are mentioning something about an "air brake" on the motor. The only ACM I've ever worked on was an LT16HD with a Baldor motor, so this is all somewhat new to me but our documentation mentions a protocol for calibrating or adjusting it. I wonder if yours has this feature and is set too tight, thus tripping the breaker? Here is a screen grab from the operator's manual:
Capture.JPG
Erik
Ex-SCM and Felder rep
[OP]
Contributor
Interesting, the manual doesn't say anything about a motor break. If you had an air brake like this though that brought the motor to a halt in 6-10 seconds, it would probably negate the foot brake, so maybe thats an upgrade. Still, I'll give the motor a good once over to be sure. I'd contact SCM support and ask them about that, but I haven't figured out how other than a generic contact us form.
Member
I would reach out to Sam Blaisco. I don’t have his contact info, but maybe pm Jim Becker, he probably has it memorized as he often provides to people.
Contributor
Sounds like the motor centrifugal switch isn’t opening when the motor hits 70 to 80% of rated speed……Regards, Rod.
Contributor
3 phase motor
Contributor
In the 415v three phase world a motor that size would have star/delta starting circuits to reduce starting current. Do you have similar in the 240v three phase schemes?
Or, on edit, do you have a dual voltage motor which can be wired for either 240v (star, or wye windings) or 415v? (Delta connection)
Last edited by Greg Quenneville; 12-28-2021 at 12:33 PM.
Contributor
With regard to the brakes, the machines that have them often have a switch for manually activating the brake so that it can be adjusted. There must be an air gap between the fan and the clutch material. The manual will describe how large the gap must be.
That said, I doubt you have one since you would not be spinning the wheels by hand if you did and you mentioned a plastic fan.
Bumbling forward into the unknown.
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