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Normal no-load power consumption for this mystery motor

T

tl01

1 mW
Joined
Oct 20, 2015
Messages
11
Location
Minneapolis, MN
I bought a couple of mystery motors on ebay http://www.ebay.com/itm/151913003555?_trksid=p2060353.m2749.l2649&ssPageName=STRK:MEBIDX:IT because mysteries are fun.

I've been trying to figure out the correct hall/phase combination with a Lyen 123770ST controller. After trying all combinations, the lowest no load (unbuilt in a truing stand) amp draw is 3.9 amps measured with a cycle analyst (correct shunt value) with a 36v battery around its full capacity charge of 41.8v (~160w). The hub spins around 500rpm at this voltage, or a theoretical ~440rpm at 36v. Both of these numbers seem really high, but I've gone through all of the possible combinations and can't find anything that is either a lower rpm or lower power consumption. Any chance this is normal for this hub? Not much for marking on the hubs. EDIT: I think these might be Mac motors, see below
 
I get about .9A@36V with my BPM2 with wheel in air.

Also, with my Infineon, (of course other combos will work and controller could be different)

Phase wires:
motor controller
blue blue
green yellow
yellow green

Hall wires:
motor controller
Red red
black black
blue blue
green yellow
yellow green
 
Switching blue and yellow on both hall and phase yielded 3.9, while switching yellow and green was a close second at ~4.5. Several other combinations were clunkier and drawing more amps, and several more sounded like they were the backwards combinations.

Any thoughts on what I could be failing to consider? On the same controller, a Q100 is less than 1 amp. I went through the all the combinations a second time even following a worksheet http://www.lyen.com/Manual/Sensored_Combination_Worksheet_V2.htm, and got the same result.
 
Why on earth would you try all 36 combinations? It's never necessary. Change only halls or phases, not both, and you will get exactly 1 valid combination of exactly 6 possible. If the valid combo is reverse, then swap just 2 of the wires (halls or phase) that you were keeping static, and then go back to the original set being swapped and find the good forward...Simple.

Yes, that no load is too high? I'd verify the measurement by the CA first. I always use a DMM or amp meter to measure no-load current. Is the 60°/120° phase angle set correctly in the controller?
 
I wanted to eliminate any room for an error in logic, which is usually where I fail, so it didn't seem terribly time consuming to just try all of them.

The 60°/120° phase angle is set to auto select, so that's a great tip. I'll look into that and verify the measurement. Thanks!

John in CR said:
Why on earth would you try all 36 combinations? It's never necessary. Change only halls or phases, not both, and you will get exactly 1 valid combination of exactly 6 possible. If the valid combo is reverse, then swap just 2 of the wires (halls or phase) that you were keeping static, and then go back to the original set being swapped and find the good forward...Simple.

Yes, that no load is too high? I'd verify the measurement by the CA first. I always use a DMM or amp meter to measure no-load current. Is the 60°/120° phase angle set correctly in the controller?
Click to expand...
 
Simple is always logically better.

Auto select is all I ever used, back 5 years ago when I still ran Lyen controllers.
 
3 amps is the best that I can get. Changing phase angle didn't result in any good combinations.

However, after doing a bit more research, I think these might be 6T Mac motors. They look identical and the format of the serial number is the same as the one in the photo at http://lunacycle.com/motors-and-esc/mac-geared-hub-motor-rear-8t-320rpm/. It seems like this would also explain the ~410rpm unloaded speed and the higher than expected power consumption (searching the forums suggest 2-3 amps is pretty typical for 36v with this motor). What's the best way to verify this? I'm planning on selling the second one since I don't need two, and don't want to subject anyone to my best guess.

Thanks for the help!
 
Drunkskunk said:
it's low resistance will cause high idle current.
Click to expand...

?? No load current is a measure related to iron core and parasitic losses. ie everything except the copper losses from resistance.
 
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