I have not used my phase converter in a while. When I fired it up the other day, the main Allen Bradley size 2 starter made a very loud noise, like a old style 60 Hz door buzzer. Despite that, the converter ran, but I decided to not use it and investigate.
This is a Size 2 starter starting a 10 HP motor.
So.
What would be the proper troubleshooting procedure here and what is likely wrong? Any ideas?
Spiders...
As in a spider or similar bug in the contactor keeping it from fully seating so it buzzes, but still seating far enough so the contacts close.
Ding dong, I think that we have the right answer. Thanks a lot. I will try to see if I can blow it out with compressed air. I may put a mothball there for the future if it does not stink up the garage too much.
Reminds me of an issue last fall. Corn dryer main blower starter was doing about the same thing. It would fire and just buzz (this one wouldn't start the blower). Turned out that there must have been an Asian beetle under the contacts the first time. Smashed him good, and it was just hammering on the contacts trying to make a good connection. It couldn't draw enough juice through the remaining pole to start the motor, so eventually it would pop the breaker.
Had something similar happen on the pressure pump for the house water. It's starting to become standard practice for debugging to check for bugs...
JW
FWIW, the size 3 contactors on my irrigation well routinely buzz. Not every time, but often. i just got used to it.
Karl
Hey Iggy,
Difference between a "buzz", and a real hard BUZZZ/SLAM/HAMMER/BANG/SLAMAGAIN is easy to hear.
The first, which it sounds/reads like to me you have, can be just some accrued dust or similar in between the armature pieces, possible even a low voltage condition.
But the louder and sometimes scary sound can be due to a loose or broken lead or cracked StaKon terminal (common on AB stuff) or a bad self-holding contact.
Take care.
Brian Lawson, Bothwell, Ontario.
Moth ball? What do you do with the rest of the moth?
Ivan Vegvary
I do not feel that it is a good thing.
It is BUUUZZZZZZZZZZ
Like a cheap 60 Hz alarm.
I will look again, try to blow out the crud with compressed air, I suspect insects at this point as Pete C said.
step 1, run to usenet. Skip the part where you examine what's causing the sound in the first place, and then try to remedy it.
SNIP
Hey again Iggy,
The AB stuff is pretty easy and straightforward to take apart for inspection and cleaning. I doubt that blowing air will do much, but hey!!
The "60 cycle buzz/hummmm" is caused by the armature pieces not getting to a full flat contact, or possibly by a (very rare) cracked shading-coil. The shading-coil is the copper flat buss in the form of a figure-8 on the fixed armature part.
Other than the noise annoyance of the buzz, it's not really a problem.
Take care.
Brian Lawson.
You are unlikely to succeed in your efforts to upset me.
There is a good reason for it.
iNot trying to be alarmist, but isn't the mothball napthalene? Mightant that go "bang" when mixed with oxygen in an enclosed space when ignited by a spark? Probably would take care of any bugs.
Pete Stanaitis
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Ignoramus19021 wrote: I may put a
On Tue, 24 Jun 2008 20:33:05 GMT, with neither quill nor qualm, "Ivan Vegvary" quickly quoth:
Iggy's apparently one helluva surgeon.
-- Everything I did in my life that was worthwhile I caught hell for. -- Earl Warren
A few years ago while visiting a friend in Florida I was asked bt him to investigate a buzzing noise from an irrigation pump motor control relay mounted in a not very well sealed outdoor housing.
The problem was similar to what you suggest, but instead of being cracked, the shading coil had corroded away, leaving not much more than a blueish green trace of its former self.
Must have been a lot of humidity inside the housing leading to galvanic corrosion of the shading coil.
We went to a supply house, bought a new relay, and installed it.
Jeff
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