Dead Felder Bandsaw

[chris weir]

I purchased a Felder FB600 Bandsaw, new, in 2011. Since that time, it has seen a few projects for a total of +/- 4 or 5 hours run time at the most. It has been a great saw until 2 months ago when I turned it on and the motor made a strange humming sound, tripped a circuit breaker, and smelled like something was burning. After resetting the breaker, it would not turn on. I tried pushing in the contactor switch and the motor would spin, and quickly trip the breaker again. After many calls to Felder, they suggested and I agreed to try replacing the capacitors. Waited a month for the capacitors to arrive, installed, and still not working. After back and forth for another month with Felder, they said it could be a bad contactor switch, but sounded like the windings in the motor could be bad. They told me to try pushing in the contactors again, but nothing happened. I told them I wouldn't be doing the repair myself, so they sent an estimate for parts and labor for a technician to come out and do the repair. Worse case scenario, they replace the wiring harness, contactor switch and motor. Parts are $1762.00 (4 kw motor and electrical switch box) and Labor/Expenses $965.00 for a total of $2727.00 if the motor needs to be replaced. Is it worth spending $2727.00 for a 13 year old bandsaw? Also a bit concerned that the motor would die, even though 13 years old, with so little run time. Opinions?

[Ron Selzer]

centrifugal switch probably stuck open in the motor
need to remove motor, remove dead end cap, free up and lube the centrifugal switch
There is a possibility that the motor is burned up from trying to start it with open centrifugal switch

Ron

[Michael Burnside]

Hard to say if time was also a factor, depending on where you live, humidity, etc. There could be some oxidation/corrosion on the windings/contacts as well. For pure runtime, it's certainly quite low.

I know 2.7k is a lot of money, but it's probably the route I would go. It's great that it can be repaired instead of thrown into a landfill as a complete waste. With a certified tech, knowing what they're looking at, maybe the ultimate repair is less.

[Kevin Jenness]

I would use a multimeter to see if the motor is getting the proper voltage, if not then there is a problem with the switching or possibly the incoming power supply.. If the motor is getting the juice it needs, I would pull it and take it to a motor repair shop. If I was not comfortable using a meter I would call in a local electrician familiar with motors and controls. Bringing in a Felder tech would not even be in the picture unless I was on a desert island with no closer resources. Did they give you a cost for the tech's transportation and expenses? Unless you live down the street from the dealer that is going to be a considerable sum. Repairing the saw is going to cost less than a new one but there is no reason to break the bank.

A local shop had a motor failure on their Felder bandsaw that was attributed to voltage fluctuations, and after replacing the motor they added a "buck booster" to the incoming line to avoid a recurrence. That was a three phase motor, and I don't know if Felder's single phase motors are equally sensitive.

[Rod Sheridan]

centrifugal switch probably stuck open in the motor
need to remove motor, remove dead end cap, free up and lube the centrifugal switch
There is a possibility that the motor is burned up from trying to start it with open centrifugal switch

Ron

Hi Ron, Felder single phase saw motors do not have a centrifugal switch for starting, they use a starting contactor and capacitor external to the motor.

Regards, Rod.

[Tom M King]

Check to see if you have a local electric motor repair shop.

[chris weir]

I think I will go ahead and have Felder do the work. They are estimating a maximum of $965.00 for labor, including travel (1 hour 20 minutes from me). A new bandsaw would be over twice the price and I am not interested in doing the work myself - I can install an a light fixture and electrical outlets, but that is the extent of my electrical knowledge. I will inquire with Felder on the possibility of electrical fluctuations on my end.

[Richard Coers]

Did you check any safety switches on the doors? Might be arcing or something and only allowing partial current to the motor?

[chris weir]

Yes, checked all safety switches; bypassed the door switch and the brake switch

[Tony Shea]

I'm assuming your start capacitor has failed. Without a this capacitor the motor is going to just sit stationary without a way to get started. The capacitor creates a phase shifted current which is how the motor gets the initial bump to start spinning. Without this your windings are just sitting there making a magnetic field creating that terrible humming you hear. Without any rotation of the motor this creates a ton of heat and will eventually burn your motor windings up.

I know this is not a safe or recommended thing to do... but if you were to unhook the belt and manually spin the motor shaft with your hand, the motor would actually start to spin. That's all a motor really needs to start it's rotation without a load attached. This helping hand typically isn't enough if your motor is under load.

If there are no centrifugal switches on a Felder motor then this capacitor is a always part of the motor circuit, which is known a a permanent split capacitor induction motor. If you think about a motor and the windings on single phase, there is no phase shifting of the power to create the opposing magnetic field to start the initial spinning of the shaft. 3 phase motors have 3 different sign waves that are 120deg apart from each other. This constant shifting of phase angles is why 3 phase motors don't require this capacitor to start the initial rotation due to the constant opposing magnetic fields. Single phase doesn't have this shifting, therefore there is no way to get that initial bump to get that heavy armature to start spinning. Hence why they throw a capacitor in that creates a phase that is shifted 90deg from the original single phase sign wave. So hard to explain this theory in text so I'm not sure if this makes any sense or not.

[Jacques Gagnon]

Tony,

Nice explanation. Thanks!

Jacques

[Rod Sheridan]

Hi Tony, the start contactor only is closed while you hold the start button, or while the start timer is counting down, depending upon the machine.

There is a separate run capacitor permanently connected to make this a capacitor start, capacitor run motor.

Regards, Rod.

[Jacques Gagnon]

…and thanks Rod for the precision…

[Tony Shea]

Hi Tony, the start contactor only is closed while you hold the start button, or while the start timer is counting down, depending upon the machine.

There is a separate run capacitor permanently connected to make this a capacitor start, capacitor run motor.

Regards, Rod.

Rod,

That is also another way to handle the start capacitor. I'm not familiar with Felder machines therefore assumed they were a permanent split capacitor induction motor. But having a start contactor would serve the same purpose as a centrifugal switch.

Do you know if Felder is using a timer relay to disengage the start contactor or is it up to the user to hold the start button for a period of time?

[mike stenson]

Ya gotta hold it down I until it's up to speed.