# Motor break in using charger?



## umurali2000 (May 3, 2010)

Charger for breaking? can you elaborate?


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## zwmaster (Nov 23, 2009)

umurali2000 said:


> Charger for breaking? can you elaborate?


Yes. I was already thinking it is something wrong...
I apparently did select wrong words for what I was thinking about.

When you have new motor (with commutator), it is a very good idea to let the motor run for long time at low power just to let the brushes settle on commutator. The phrase "brake in" is from google translate and I think I did see this somewhere before.

To buy a powerful power supply just for this work is sometimes not feasible and that is why I asked if charger with capability of low voltage setup could be used.


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## umurali2000 (May 3, 2010)

It all depends on the power at which we will be running the motor ..

and what rating charger being used? 

if your motor is 220V DC ... 

charger you are using for less than 100V then the operating current will be high even for lesser power ... so decide the points  

hope this answered


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## zwmaster (Nov 23, 2009)

For example a 11" series motor is pulling around 20-30A @ 12V freewheeling, no load. 
The question is, will the inductive type load that is motor presenting be a problem for charger that is used to be connected to LiPO battery pack.
Could Manzanita for example handle it?

I have also idea to use a small inverter welder that has a current regulation pot on it. 
But here i don't know if it can be trusted not to let the motor spin out of control.


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## Tesseract (Sep 27, 2008)

zwmaster said:


> For example a 11" series motor is pulling around 20-30A @ 12V freewheeling, no load.
> The question is, will the inductive type load that is motor presenting be a problem for charger that is used to be connected to LiPO battery pack.


40-80A is a more typical unloaded draw for a 9" to 11" motor, and it still takes a brief burst of several hundred amps to accelerate the motor from a stop. Also, yeah, the charger *might* not like seeing an inductive load. Depends on a lot of things. You could sidestep all of this by putting a battery in parallel with the motor and charger.

An inverter welder - at least in DC output mode - *should* have accurate current regulation. Once again, though, you need the battery to deliver that initial burst of current.

Finally, the ideal method for breaking motors in - to develop a nice patina on the commutator bars and to fully cure the winding varnish (e.g. - Kostov) - is to run them at 1500-2000 rpm (11" to 9") at, say, 50% of the continuous or 1hr current rating. If that rating is 200A then you will want to load the motor just enough to make it pull 100A. This is only ~1.2kW input to the motor, but it is way outside the province of the usual charger. Not a problem at all for a motor controller - they usually have accurate current regulation (notable exception is the Curtis 1221/1231) - and you can usually get just the right amount of loading by having the motor drive the transmission in neutral.

Major may have something to say about this, but since I derived this process from him in the first place...


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## zwmaster (Nov 23, 2009)

I have checked the welder in the corner of my garage and it has fine current regulation form 5-180A.
Starting with car battery is a good idea. Inverter Welders have "hot start" feature for arc ignition. Basically it rises current on start and this is not something i would want on motor brushes/comm.

thnx Jeffrey


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