Machine eating capacitors

[talon]

I have a machine 8270 that ate 3 sweep motor capacitors in the last 3 months. I changed the 3rd one last night. The sweep motor hums and does not start from 270 back to zero position? The capacitors were brand new from AMF back 3 months ago and installed properly by myself. I changed 5 brunt C1 pins that appeared to be bad. What other reason would there be that a certain machine eats more capacitors than others? The sweep motor is either a Westinghouse or General electric with a solid state switch and appears to be fine with no overloading issues. Chassis are SS Omega-Tek with enclosed contactors.

[Kat]

A big cause for this is start windings staying engaged, amongst others.

[70/70]

Try swapping chassis with another machine and let run. Sounds like a sweep contactor sticking

[Tablejam]

I have seen bad contactors do this- failing in such a way that it tries to start and stop the motor at the same time- caps don't like that.

[old-school-mechanic]

LOL

Yes they seem to want to explode when contactors start and stop a motor at the same time.

Uncle bob
isolate the problem, Put said motor on a different lane, Then put chassis on a different lane (not the one motor was put on) ........... Sit back and watch !

[70/70]

........... Sit back and watch ![/QUOTE]
How about sit on top of machine and watch. Have clean drawers handy

[8270king]

LOL

Yes they seem to want to explode when contactors start and stop a motor at the same time.

Uncle bob
isolate the problem, Put said motor on a different lane, Then put chassis on a different lane (not the one motor was put on) ........... Sit back and watch !

Sage advice here above!

I bet it is the chassis contactor

[wb8yjf]

From personal experience and having to change my drawers more than once - I agree the normally closed contacts are probably getting stuck on occasion. The older Allen Bradley's aftermarket contacts are crap - they tend to move around and on occaision they fall out of their mount - *boom*.

[Tablejam]

From personal experience and having to change my drawers more than once - I agree the normally closed contacts are probably getting stuck on occasion. The older Allen Bradley's aftermarket contacts are crap - they tend to move around and on occaision they fall out of their mount - *boom*.

Waaaay back in the olden days, one time I was standing on a wireway when one of those things exploded- *BOOM*, yeah I just about jumped off the machine!

[scotto7]

I reckon it could be a brown trousers day especially standing on the wireway lol.

[hilltop bowling]

Exploding capacitors are usually caused by the motor S relay in the chassis having a screw missing and upper and lower contacts making at same time or the sweep reverse relay in the rear panel going bad.The sweep run switch is a 3 amp switch and is low voltage .The sweep reverse relay is a 15 amp switch and is in the 120 volt start winding circuit.

[cdsand5]

I have had 2 caps go boom in the last year or so, both were at night when I wasnt here and neither time did my chaser hear them. Both turned out to be faulty AB contactors. As stated before the points got turned sideways and were trying to start and stop the motor at the same time and the reason my chaser didnt hear them explode was because he was up front hanging out with the front counter crew.

[talon]

The contactors are enclosed Allen Bradley. The capacitors are just going open both times. The sweep motor never overloaded at all. I have had an exploding capacitor or 5 in my days when a contactor sticks..... The entire sweep motor was changed about 1 month ago because of a leaky gearbox. This does not appear to be the issue. None of the capacitors exploded .....

[wb8yjf]

... None of the capacitors exploded .....

Well, thank GOD for that! 'Sploding caps ain't good.

[70/70]

I was testing an unknown chassis one time, standing on the lane. Plug machine back in, cycle, BOOM. At least the wireway cover was in place. Is there an emoticon for peeing pants?