motor overheating

[Casey]

hey guys, i have a national combo motor that is overheating. it currently has a quality start switch. The carbon brushes were just about gone. replaced them. Overheated shortly there after. I replaced the switch with a lewus switch. motor hummed but didn't turn. not sure whats going on. The klixon switch had wires on the 1 and 3 terminals. supposed to be 1 and 2 isn't it? is it possible that i fried the klixon by not wiring it correctly? can a start switch cause a motor to overheat? This is my last motor. I need it to work.

[Mike Stalker]

Re: motor overheating

Casey, put a continuity tester on the klixon and see if you can read across it. The breaker should be fine, if the breaker is open then it will not humm.
Sounds like you lost the Quality switch and the Lewis isn't set properly. If it wired properly, play with the adjustment and see if you can get some rotor movement.

If the motor was on the sweep then maybe you just lost the reverse winding, in which case the motor will run on the table.

I use the Lewis switches on some of my motors because they were here; I don't really care for them because they are adjustable. If they were fixed switches for the right horsepower then they would be okay.

I perfer the Stahl's motor start relay that goes into the wireway.

[KLH]

Re: motor overheating

hey casey the motor start relay that goes in the wireway is the way to go just rig a machine tranfer the motor to solid state and pull the good motor off the machine for a spare..good luck again Kevin

[TheGMan143]

Re: motor overheating

The klixon is just a switch, and your motors are rated for continuous duty... if the motor is working correctly, it will not cause it to overheat, however, if the motor has a problem of some kind and the klixon is malfunctioning (not allowing the motor to shut off during an overload), it can overheat the motor.

The carbon brushes must be a certain length, as they are under spring pressure and run under friction against the brush ring... too much spring pressure from the brushes being too long (causing the springs to compress too far) can burn the brushes and carrier from friction heating, and could make the motor run harder due to the braking action of the brushes overloading it. Incorrect brushes or brushes cut from bulk carbon rod (and cut too long) can cause this.

If your starting switch (be it mechanical or electronic) is not changing over to the "run" windings after the motor has 'spun up', it can definitely cause it to overheat... it's either running exclusively on the start windings (usually mechanical switches are good for this)... in the case of SS starting units, some can cause the start windings not to shut off when the run windings kick in, also causing overheat.

The start windings on most continuous-duty motors are only designed for intermittent-duty to provide a big push that gets the motor spinning from a dead stop, then are turned off and let the run windings move the motor along. If left to run for an extended time, those hi-torque windings will self-destruct from overload/overheat.

[Rep]

Re: motor overheating

I'm thinking the new switch needs some toying myself. As stated earlier if the klixon was fried it wouldn't even hum... You'd get nothing at all. We use the Lewis switches and they can be a bit touchy sometimes, if need be play with the adjusting screw on the bottom and go 1/4 turn at a time if you have to (if it's real touchy) good luck and keep us posted!

[JimDorsin]

Re: motor overheating

I agree with Mike and Kl, the Stahls ( actually GE manufacturers them, and Stahls just is one supplier)potential relays are the way to go. I have been using them for 2 years now without a problem

[Lampie]

Re: motor overheating

If the motor was on the sweep then maybe you just lost the reverse winding, in which case the motor will run on the table

<font size="2" face="Verdana, Helvetica, sans-serif">This is new to me, explain please [img]/content/btubb/images/%%GRAEMLIN_URL%%/confused.gif[/img]

Martin

[Casey]

Re: motor overheating

I cut down the brushes just a hair. never had that problem before. I also put on a new quality switch that just got here today. The old one was wired incorrectly anyways. one of the wires was on the wrong terminal in the receptical. go figure. wonder how it ran to begin with. seems to me none of my machines are wired the same way. But they seem to work. thanks for the input, always appreciated.

[Mike Stalker]

Re: motor overheating

Lampie, I do not have much time but I will let the guys put their thinking caps on. I believe your system is 220.

Hint
In the US with 110; the sweep motors require five wires and the table motors require three. I will let the guys take pot shots at this.

[TheGMan143]

Re: motor overheating

Originally posted by Lampie:
</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">If the motor was on the sweep then maybe you just lost the reverse winding, in which case the motor will run on the table

<font size="2" face="Verdana, Helvetica, sans-serif">This is new to me, explain please [img]/content/btubb/images/%%GRAEMLIN_URL%%/confused.gif[/img]

Martin </font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">As long as the motor can run, it can power a table... the table doesn't need to be reversed by the gearbox at any time. The sweep, however, needs a set of wires that can make it run in reverse (in the 'old days', just for the switch on the back panel... nowadays, the reversing function is used on many scoring systems as well).

I don't know about the new solid-state start switches out there, but the older Quality switches required a modification in the front wireway to allow the reversing function to work on the sweep... if the mod wasn't done, you couldn't reverse the sweep with the SS switch installed on the motor.

[Lampie]

Re: motor overheating

I have five wires on both sweep &amp; table motors, the motors run on 220V, and have 3 windings; 2 main windings wired serial between hot and zero, and one start/break winding(with a centrifugal switch serial)parallel over one main winding(so actually my 3 motor windings are 110V too). The start/break winding plus the centrifugal switch can be reversed.
If the start/break winding(also my reverse winding) is fried and lost, the motor won't start on sweep nor table. Our table motors need the start/break windings too.
I still don't understand how a motor can run on the table with a fried start winding(even on 110V)
[img]/content/btubb/images/%%GRAEMLIN_URL%%/confused.gif[/img] [img]/content/btubb/images/%%GRAEMLIN_URL%%/confused.gif[/img]

Looking forward to your explanation...

Thanks. Martin

PS I was thinking that you might use one of your main windings as a start winding but no, impossible... you would loose 1/6 horse.. [img]/content/btubb/images/%%GRAEMLIN_URL%%/laugh.gif[/img]

[Mike Stalker]

Re: motor overheating

Table motor cables with five wires:

CT and Y meet on the terminal strip and are dead ended there.

Z is your start winding, X is the run winding and nil is the neutral.

[Mike Stalker]

Re: motor overheating

I have to hit this in sections because I am very short on time this weeekend.


In three wire table cable wiring, CT and Y are jumped together at the plug connection.

[Lampie]

Re: motor overheating

I understand what you mean with the above.
Just don't know what you mean with a "reverse winding".
But never mind, must be my bad.
Martin

[Lampie]

Re: motor overheating

I didn't know table motors in the US were running on three wires, so I learned something new.
In the Netherlands sweep and table(combo)motors are wired the same, which I think is better because it's easier to change motors and less stock is needed. But that's just my opinion.
Martin