# Please help identify this Sepex



## ken will (Dec 19, 2009)

Does anyone have any idea what this is?
The Field windings Measure 1ohm.
I can not find any reference to the number on the side - 283024007.


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## major (Apr 4, 2008)

ken will said:


> Does anyone have any idea what this is?


Looks like 8 inch diameter. That right? The only US guys making 8" DC motors resembling that are (or were) Advanced DC out of Syracuse. They got bought out by Kenetec (sp?) and then by someone else, I think. Hard telling who's who any more  But does it matter?


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## ken will (Dec 19, 2009)

I don't have matched Sepex controller.

I do have a 24V 5A PWM controller for the field and a 72V 400A PWM controller I can use for the armature, but I have no idea what is safe to push it at.

I think I will mount some temperature sensors on the motor and play around with the 2 controllers. 

I am assuming ... If I keep the temperature down..
and don't go too low with the Field current at low RPMs ...
I should be okay?


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## major (Apr 4, 2008)

ken will said:


> I don't have matched Sepex controller.
> 
> I do have a 24V 5A PWM controller for the field and a 72V 400A PWM controller I can use for the armature, but I have no idea what is safe to push it at.
> 
> ...


You say the field is one Ohm. So your with your 5A PWM controller you'll only be able to use 0 to 5V. Maybe 6 or 7V if she warms up. 5 Amps field current may be less than "normal" or full field for this motor, meaning you may only be able to operate in weakened field condition. Using it at no load to test won't present much problem and you can get use to the speed changing with varying field current. Remember, less field current means faster RPM. So keep the armature voltage low so you don't overspeed.

You see trouble if you start to load the motor (meaning high armature current) as in sparking and loss of torque and possibly stalling out unless you can boost field current. I would think a proper field controller for this motor would need 40 or 50 Amps max and normal of 15 or so.

Good luck.


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## ken will (Dec 19, 2009)

Thanks for the info!

I will try to get a better controller for the field.
If I just connect a 12v battery directly to the field I will get 12A 
Or 2 batteries will get 24A.
..good enough to run some tests.


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## major (Apr 4, 2008)

ken will said:


> Thanks for the info!
> 
> I will try to get a better controller for the field.
> If I just connect a 12v battery directly to the field I will get 12A
> ...


Yep, but watch the Watts. With the field, it all goes to heat. So P=V*I. 12*12=144W is probably O.K. 24*24=576W or over 1/2 kW will heat up. I suspect it'll take minutes, not like seconds, so give it a try, but don't go out for coffee while you have it hooked to the 2 batteries


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## TEV (Nov 25, 2011)

major said:


> Yep, but watch the Watts. With the field, it all goes to heat. So P=V*I. 12*12=144W is probably O.K. 24*24=576W or over 1/2 kW will heat up. I suspect it'll take minutes, not like seconds, so give it a try, but don't go out for coffee while you have it hooked to the 2 batteries


He want to connect a 12V battery "directly" thinking that it will get 12A. At least this is how he write it.

I may be rong, but this is how I read his post.


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## major (Apr 4, 2008)

TEV said:


> He want to connect a 12V battery "directly" thinking that it will get 12A. At least this is how he write it.
> 
> I may be rong, but this is how I read his post.


That's how it usually works. 12 Volts across the 1.0Ω field results in 12 Amps. What do you see differently?


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## TEV (Nov 25, 2011)

major said:


> That's how it usually works. 12 Volts across the 1.0Ω field results in 12 Amps. What do you see differently?


Sorry, my bad (I=V/R) . 

I will just blame the late hour


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## ken will (Dec 19, 2009)

It's Alive!!!
I put a 12V battery to the Field coil and my motorcycles controller to the Armature. It runs good in both direction. 
The brushes spark a little above 50 volts, more so in one direction than the other.
The motor has been sitting in an unheated garage near the ocean for several years so I wasn't sure if it would even turn.

Thanks again for your suggestions.


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## Salty9 (Jul 13, 2009)

Sparking may be related to the armature needing to be dressed or resurfaced after sitting in a corrosive atmosphere.


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