'artificial' load on electric motor???

[Superslinky]

Hey all, I've got an electric motor in house that I need to test for a period of a couple days and am looking for a way to load it down. We've all thought of some sort of fly wheel or fan but thought maybe some of you have had success with other ideas, ie braking systems, gear boxes, etc.

Any and all ideas are welcome.

Thanks!!

 

[MintJulep]

Flywheel don't add load at constant speed.

Fan would be fine.

 

[unclesyd]

For a long test I would use a generator and dump the power through some resistance heaters.

For short duration test a pony brake works very well so long as it stays cool.

Hooking the motor to an oversize gearbox would work under driving the box.

There are continuous duty hysteresis brakes on the market. This would be viable if this not a one off test.

 

[MiketheEngineer]

Or pump some water?? Up a hill and then recover it and re-pump??

 

[TheTick]

Fans or pumps are good.

 

[asimpson]

An generator. Could recover energy to do some work. Heat water, light house.

 

[Tmoose]

Watts, kW, MW ?

 

[rmw]

Another suggestion is a electromagnetic retarder. Not knowing your size, I can't recommend a model, but they make small ones that can be used as a "dyno" and they are self cooling using air. Google " Telma " and " Klam ".

rmw

 

[drawoh]

Superslinky,

I made a brake once with some string and some weights. I think I had a flanged pulley to keep the string in place.

JHG

 

[racookpe1978]

You need a load that you'd feel comfortable sleeping next to.

"Unmanned" testing overnight => Murphy's Law of guaranteed failures (fire, flooding, feast or famine) at the worse possible time.

 

[flash3780]

Do you need to quantify the load? Stirring a bucket of water would apply a pretty continuous load. A fan would be another option. Both are pretty cheap and aren't very likely to burn down your house.

A paddle stirring a bucket of water is nice because you can adjust the load by increasing or decreasing the water in the bucket. With a fan, have to change fan sizes.

Of course, speed matters. If you're spinning at 5000 rpm water is pretty much out of the question. Imagine the mess, eh?

 

[MintJulep]

With a fan, have to change fan sizes.

Or just change the restriction.

 

[flash3780]

Or just change the restriction.

Good point. You'd want to make it a ducted fan with some louvers in that case.

 

[DAVIDSTECKER]

If you can hook up a hydraulic pump to it you can take pressure relief valve and block the through port then regulate the back press and dump the rest to tank. this should keep the load constant but you will need to have a large enough tank to deal with the heat in the oil.
I do something simular to keep a constant test load on items. It's down and dirty, and hard on the valve, but it's cheap.

 

[ScottyUK]

You still need somewhere to dump the energy - make sure the oil cooler is generously sized.


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If we learn from our mistakes I'm getting a great education!

 

[bithkits]

How about an eddy current brake? That way you can vary the load and have no brake pads that will wear out.

Adriaan.
I am a Mechatronics Engineer from South Africa.

http://www.martin-electronics.co.za