DC motor test.

[Ian Rogers]

Someone just dropped this off for me to test!!

230VDC motor.....2.75PHP...

How do I test it?? Why is there a frequency spec??

 

[MaxHeadRoom78]

A common T.M. motor I assume the Hz refers to the supply?
Just connect a bridge to any AC supply up to 240, but if you use the full voltage you will need to remove the flywheel as it will take off in a hurry.
The safest is an automotive battery.
If you use it for general purpose use, especially if it involves reversing, you will need to take the flywheel off, as they are generally threaded on.
Max..

 

[Les Jones]

Hi Ian,
I think this is just a permanent magnet DC motor. I think the frequency must refer to the speed control board. Although it is rated at 230 volts I would start by testing it with a 12 or 24 volt DC supply. If you have a tachometer verify the speed is about right. (So for 24 volts I would expect it to run at about 480 RPM) Also monitor the current. I would expect it to take less than an amp off load. I have a 600 watt 180 volt motor on my milling machine. When I tested it before running at full voltage it took 200 mA with 40 volts. Before testing it I would have a look at the brushes. I would finally test it using a variac and bridge rectifier to test it over its full speed range.

Les.

 

[MaxHeadRoom78]

You can obtain a controller for it from one of the KB line, many on ebay, if you do not have the original that came with the T.M.
The KB selection come as SCR bridge type or PWM, with PWM obviously being the superior version.
Max.

 

[Ian Rogers]

Cheers Lads

I just connected it to a 12v battery... Runs just sweet!!

 

[gophert]

Cheers Lads

I just connected it to a 12v battery... Runs just sweet!!

Can you reverse it or is there a bridge rectifier built into the motor? Just wondering why they have the frequency spec.

 

[MaxHeadRoom78]

The rest of the label info may make it clearer?
Max.

 

[Ian Rogers]

The rest of the label info may make it clearer?
Max.

What rest!! That's the label..

Power.........2.75PHP
Volts...........230VDC
Frequency....50/60Hz
Speed..........4800RPM

Nothing else....

 

[MaxHeadRoom78]

The initial part of the label descriptions could not be seen, at least by me.
As already covered, I think it is the voltage supply rating, but unusual.
It may have had one of the SCR bridge type controllers that go directly across the AC input?
Max.

 

[Dr_Doggy]

does motor spin flip if you reverse polarity? .. my kool-atron had rectifier on its dc fan to keep it spinning only one way

 

[MaxHeadRoom78]

.. my kool-atron had rectifier on its dc fan to keep it spinning only one way

Usually done with a small bridge rect in front of the fan.
Max.

 

[dr pepper]

Get someone very brave to stand on it while you apply rated power.
I test starter motors like this.

 

[gophert]

Get someone very brave to stand on it while you apply rated power.
I test starter motors like this.

That is a really bad idea for a motor with a flywheel - easily break and ankle and it can get worse from there in a hurry. Use a proper clamp or motor mount. There are holes in the face of the motor. mount them to something rigid.

 

[dr pepper]

Yeah your probably right, plus the inrush might be too much for the brushgear.
Starters make you jump too.

 

[MaxHeadRoom78]

For most applications the flywheel should be removed, in some cases the CW/CCW rotation is marked in order to determine the nature of the thread direction, the odd ones are just keyed on.
Max.

 

[Ian Rogers]

I was just asked to test it..... Works on 12v so Job's done... I don't know / care what its from

 

[dr pepper]

I've seen them before, as max said tread mill.
They make very good generators.

 

[gophert]

I've seen them before, as max said tread mill.
They make very good generators.

Yeah, I never understood why they are connected as a motor. They should force the user to generate power for the TV he watches while he works out.