Motor current guestimation.

[itsmoked]

I have about a 3lb 12VDC gear motor.
No labels, no plates.

I am going to be using it on a hard to define load and I'm trying to figure out how to tell if I'm overloading it. I can't see the brushes as it's a fully enclosed motor.

I can easily measure the current and I can measure the case temp. I don't want to fry it before the case has time to heat up.

Any rules of thumb or suggestions welcome.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[roydm]

Perhaps you could look at a number of similar motors and make a table Watts per lb?
My guess (based on nothing that makes sense) 24 W/lb or 6 Amps
Good Luck
Roy

 

[7anoter4]

Hi itsmoked,
May be or may be not…
I found on the web this:
These 24VDC Type 02 52mm diameter gear motors are made with steel gears (not plastic or sintered metal). They are real stout motors. They weigh about 2.9lbs each. We sampled many other manufactures and the gears would strip or the windings would burn up, we had no failures with these.
These are the links:

http://www.superdroidrobots.com/product_info/IG52GM-02.gif

http://www.superdroidrobots.com/shop/item.asp?itemid=841&catid=7

Regards

 

[waross]

I have about a 3lb 12VDC gear motor.
No labels, no plates.

If a newby had posted this!!
Check the armature resistance and take a guess at how many watts it can safely dissipate. If you just get in the ballpark, you should be able to protect by conservative case temperature protection.
And don't forget, measuring the armature resistance is a challenge with the non linear characteristics of the brushes.
I hope this is for a client and not for making egg-nog in quantity from home grown eggs. LOL

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[itsmoked]

No not an egg nog devise.

I presented the weight only as a size reference. No it's not a 500HP motor. No it's not a toy fan motor. It's a 3 lb motor.

Generally I would guess I could look at the brushes arcing and see if I've crossed some point from nominal arcing to "trash them immediately" arcing. But as stated I can't see them.



Keith Cress
kcress -

http://www.flaminsystems.com