Start trips breaker

[dusty]

A digital meter does not lend itself to transient fluctuation indication.

The old fashioned kind would be better(d'arsonval movement).

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The first link and voltage meter with a needle would be a analog meter ? sort of like the old automobile volt / amp gage , I use a digital meter like the 2nd link for radio repair , I use it for monitoring DC voltage . I can monitor line voltage from the power supply as well as power consumption in all radio operations , especially when in the transmit mode , they do have their limitations but are also very compact and easy to install . the 2nd link is a AC operations monitor .

I was thinking more along the lines of these understanding that most will not have a scope meter. The old Simpson 260 has been a work horse for many years and has survived a lot of rough handling. A Simpson 360 would do the job as well. I most frequently chose the Fluke 189 (especially in the woodshop).

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[Hobbyman2]

A digital meter does not lend itself to transient fluctuation indication.

The old fashioned kind would be better(d'arsonval movement).

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The first link and voltage meter with a needle would be a analog meter ? sort of like the old automobile volt / amp gage , I use a digital meter like the 2nd link for radio repair , I use it for monitoring DC voltage . I can monitor line voltage from the power supply as well as power consumption in all radio operations , especially when in the transmit mode , they do have their limitations but are also very compact and easy to install . the 2nd link is a AC operations monitor .

I was thinking more along the lines of these understanding that most will not have a scope meter. The old Simpson 260 has been a work horse for many years and has survived a lot of rough handling. A Simpson 360 would do the job as well. I most frequently chose the Fluke 189 (especially in the woodshop).

20220124_082335.jpg20220124_080542 (2).jpg

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Now I got ya ,,, I was thinking more in line of incorporating something a little more permanent . I have a field piece meter set up that I have had for many years when I was working in the trades , that has also served me well , temp sensors , cfm . clamp on amp meter , C02 detector and so on that all work with one meter . trouble shooting a non working motor could require a lot of detail , most all of these meters will help ?
Calculating RMS . https://www.youtube.com/watch?v=ue0wtlrmCJE

[JPG]

A digital meter does not lend itself to transient fluctuation indication.

The old fashioned kind would be better(d'arsonval movement).

Might that not depend on which model multimeter is being used.

An old d'arsonval meter typically is not damped and therefore lends itself to transient observation. all this assumes no processing of input signal other than attenuation/scaling/rectification. That cannot be said of digital meters which require conversion from the analog input and periodic sampling which obscures the fluctuations.

[dusty]

A digital meter does not lend itself to transient fluctuation indication.

The old fashioned kind would be better(d'arsonval movement).

Might that not depend on which model multimeter is being used.

An old d'arsonval meter typically is not damped and therefore lends itself to transient observation. all this assumes no processing of input signal other than attenuation/scaling/rectification. That cannot be said of digital meters which require conversion from the analog input and periodic sampling which obscures the fluctuations.

The only transient that is to be observed is the momentary drop in voltage across the motor windings at the moment of startup. Yes, a wave form analysis would require something other than a multimeter.

[Hobbyman2]

I witnessed a person replacing parts with out testing the old parts , this may not be the best policy , to ask why a motor is popping the breaker is not the same question as ,,, how do I find out why ? to start ,, I would check the speed dial to see if it is in the slow speed setting before turning it back on , it can be set by spinning the shaft by hand while adjusting the speed dial , next plug the motor directly into a feed line if possible {with out a ext cord} . if it still pops the breaker unplug it , I would open the case to see if there are any wire anomalies such as bare melted wires or signs of a flash burn . say a wire burnt off the capacitor and is in there arcing out , or the switch could be going out excreta , test he capacitor with the analog meter or a cheap capacitor tester , Harborfreight use to sell one that wont break the bank , there is a possible chance it is not any good now any way . I have seen breakers go bad especially pushamatic . If all these test fail to indicate a problem remove the belt and check to see if the motor spins freely , smell it , if the brushes are bad most of the time you can smell it when you open the housing . plug it back in and see if the motor will run with out the belt on. should tell you if the motor was any good or a bearing is in need of service , there are more things to test once you have done all of this . if it runs this is when the other meters come in to play . replacing parts might get it running but may result in a reoccurring problem .once running check the amp draw with a amp meter and make sure it is running with in its limits, there is a tag on the motor , a scope will also tell you if the sign wave is correct or if there is a issue with internal parts , diodes , brushes and such, ,you will find a rating plate on the motor , rla means running load amps . fla means full load amps .also be sure the supply volt / amp will support the operation, turn off everything else on the circuit ,
it should be checked , just my .02

[DLB]

A while back BuckeyeDennis posted information on conventional headstock Volts/Amps using an oscilloscope with a current probe on one channel and including startup: viewtopic.php?p=189430#p189430 Especially noteworthy is that in Dennis' case the start current was ~400% of steady state max and ~250% of circuit breaker during much of the startup period. I found it very informative, though it may or may not not have much to do with the OP's case. One of the takeaways is that the motor normally draws more than enough current to trip a breaker, and the key to not tripping the breaker is how long it takes to reach normal operation.

- David

[Hobbyman2]

A while back BuckeyeDennis posted information on conventional headstock Volts/Amps using an oscilloscope with a current probe on one channel and including startup: viewtopic.php?p=189430#p189430 Especially noteworthy is that in Dennis' case the start current was ~400% of steady state max and ~250% of circuit breaker during much of the startup period. I found it very informative, though it may or may not not have much to do with the OP's case. One of the takeaways is that the motor normally draws more than enough current to trip a breaker, and the key to not tripping the breaker is how long it takes to reach normal operation.

- David

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Thanks
I had not seen his article , a surge protector can also be of some help , a slow blow fuse can also help in a motor circuit . that can also help in trouble shooting a issue like the OP , if the breaker trips immediately or if there is a short delay etc ? there should be a time factor involved .

[dusty]

I wonder if anything has been done to help the OP. Dingo, can you use your Shopsmith now or does it still kick the breaker?

[dusty]

Here is a thread that contains a simplified drawing of the motor circuit, The only circuitry (external to this sketch) includes the power cord and the switch. Hope this provides some assistance,

viewtopic.php?t=18945

[JACOBEIS]

I have a similar problem my motor runs fine with no belts. I have cleaned and oiled the Sheave and shaft on the motor and on speed control,
When I put the belts on and have it set to slow the motor Sheaves DO NOT open and the breaker trips. If I manually pull the motor Sheaves apart
it will run until the motor Sheaves start to close.
How do they open with that spring.
I have it plugged in a 20 AMP outlet that has nothing else attached to it
The belts are pliable.
I don't know what else to do.
Any help would be greatly appreciated