# Moenergy motor?



## cricketo (Oct 4, 2018)

I don't know what the "2 small white wires" are, but do you get continuity between the big terminals ? Spin the armature by hand while testing, see if you're getting continuity more or less evenly across all 360 degrees of rotation.


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## palmtree (Jul 14, 2016)

Yep. It's hard to tell about all the way around 360 degrees, but definitely every place i stop hand turning has continuity all the way around. The buffer didn't have a regular contractor it had more of a "soft start" mechanism to energize the motor. I think the 2 small white wires have something to do with it. I may need to search for a wiring diagram in the tenant B7.


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## cricketo (Oct 4, 2018)

I still don't get what are the "buffer" and "2 small white wires" you're referring to. This is a brushed PM DC motor, the only wires besides the armature it may have is a temp sensor, which is irrelevant to motor not spinning. Connecting a 12v automotive battery to the motor should get it spinning without any additional circuitry.


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## brian_ (Feb 7, 2017)

cricketo said:


> I still don't get what are the "buffer" and "2 small white wires" you're referring to.


The "buffer" would be the Tennant B7 floor burnisher which the motor came out of.


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## DMPstar (Mar 2, 2016)

Take it apart and inspect/clean the electrical components inside if the 12V battery doesn't spin it. No spark when hitting it with the gator clip?

History unknown or taken from a working Buffer?


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## palmtree (Jul 14, 2016)

No spark when touched. Tried it with 24v and 52v. I don't know what those little white wires are either. I actually have 2 of these motors. They are from floor burnishers with dead batteries (according to previous owner). I'll check out the other one. I may try attaching 36v to the other one while it's still installed on the buffer.


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## brian_ (Feb 7, 2017)

There is a serial number and something else engraved in the case above the label... what else does it say there?
In a quick search I found one online listing for the ME0709 (other than Motenergy's usual useless listing), and the cable with the two white wires is not in that one... and that listing says "No temperature sensor", suggesting that another version could have a temperature sensor.
So my guess is that the temperature sensor theory is correct, but it's only a guess.


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## cricketo (Oct 4, 2018)

Temp sensor would probably be a thermistor. Can check for resistance at the ambient temp and then take it outside or something to see the change.

When battery is hooked up, does the shaft show any signs of life ? Can be it be spun by hand while power is connected ?


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## palmtree (Jul 14, 2016)

Well now I feel silly. My old jumper cables are apparently broken somewhere in there. I used a different set of cables and sparks flew and the shaft spun like a champ.
Sorry I washed your time.
Now to the spec label.
It says 24-72v and 104 amps continuous duty. Do you think it will pull more current in bursts? I wonder because it says 8.8hp (max) which is about 72v at 104 amps. I'm trying to figure out which controller would work well but I dont want to spend more than necessary for an overkill controller. It's for a little tractor conversion.


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## cricketo (Oct 4, 2018)

It should be able to take twice the current for about 30 seconds.


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## palmtree (Jul 14, 2016)

Okay thanks. I guess a 250 - 300 amp controller should work fine.


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## floydr (Jun 21, 2021)

I bought a cheap 60A dc motor pwm controller (listed as 100A on ebay but reading the ad it is 60A) think it was $17 maybe less to my Tenant motor out nice being able to run the rpms of motor up and down. Your motor is in better shape than mine. Mine is only 100A continuous. Since the 709 can do 300A for 1 minute, was hoping it would be able to do 250A for 30 seconds. 
Later floyd


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## palmtree (Jul 14, 2016)

Ya I suppose that just because it looks like an me0709 and it's made for 24-72v, it doesn't mean that it is an me0709. I don't want to go overboard on the controller but I also don't want to limit the motor by the controller.


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## brian_ (Feb 7, 2017)

palmtree said:


> Well now I feel silly. My old jumper cables are apparently broken somewhere in there. I used a different set of cables and sparks flew and the shaft spun like a champ.


Well, stuff happens. 



palmtree said:


> Now to the spec label.
> It says 24-72v and 104 amps continuous duty. Do you think it will pull more current in bursts? I wonder because it says 8.8hp (max) which is about 72v at 104 amps. I'm trying to figure out which controller would work well but I dont want to spend more than necessary for an overkill controller. It's for a little tractor conversion.


More complete specs are available, as noted earlier...


brian_ said:


> In a quick search I found one online listing for the ME0709 (other than Motenergy's usual useless listing)...


... including the (bolded for emphasis) short-term maximum current:


> Motenergy ME1003 PMDC electric motor
> Brush-Type motor.
> Permanent Magnet Direct Current motor
> Efficiency 92% at 48 VDC.
> ...


The torque constant (not "constant torque") of 0.20 Nm/A implies 20.8 Nm at 104 A (approximately regardless of speed) - and a burst of 80 Nm at 400 A - with voltage requirement dependent on the speed and current. The no-load speed at 72 V is listed as 3450 RPM (the result of the motor constant of 48 RPM/V), but at 20.8 Nm the speed would be about 3000 RPM to deliver 8.8 HP.

Real motors are certainly not ideal, but the ideal model of motor constants (listed here as KV = 48 V/RPM and KT=0.2 Nm/A) is still useful, along with the basic relationship of power = torque * speed.


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## floydr (Jun 21, 2021)

Note That the me1003 has double brushes not the same motor
later floyd


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## remy_martian (Feb 4, 2019)

It's a tractor...why do you want to run the motor beyond its continuous rating?


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## palmtree (Jul 14, 2016)

I think those specs are for the me1003. Mine seems similar (but may not be the same as) me0709. I guess there's really no way to know for sure.


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## brian_ (Feb 7, 2017)

palmtree said:


> Ya I suppose that just because it looks like an me0709 and it's made for 24-72v, it doesn't mean that it is an me0709. I don't want to go overboard on the controller but I also don't want to limit the motor by the controller.


The motor constant can be approximately determined by applying various voltages (or even just one) and observing the resulting no-load speed. If KV is the same as an ME0709 then KT will be, too (KT is just the inverse of KV, in appropriate units of measure).


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## palmtree (Jul 14, 2016)

remy_martian said:


> It's a tractor...why do you want to run the motor beyond its continuous rating?


I don't know that I do. It was a 12hp gas tractor, so I thought I'd like to be on that ball park. 
What I know I don't want to do is spend the $ for a controller that's overkill.


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## brian_ (Feb 7, 2017)

palmtree said:


> I think those specs are for the me1003.


Oops... clicked the wrong link! Sorry. But the idea is the same - just find anyone listing more useful specs. Even the Motenergy page lists "300 amps peak (1 minute) and 125 amps continuous", which may be enough information.


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## palmtree (Jul 14, 2016)

brian_ said:


> The motor constant can be approximately determined by applying various voltages (or even just one) and observing the resulting no-load speed. If KV is the same as an ME0709 then KT will be, too (KT is just the inverse of KV, in appropriate units of measure).


Oh I didn't know that. Thanks for the info.


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## palmtree (Jul 14, 2016)

brian_ said:


> Oops... clicked the wrong link! Sorry. But the idea is the same - just find anyone listing more useful specs. Even the Motenergy page lists "300 amps peak (1 minute) and 125 amps continuous", which may be enough information.


Ya. I'm just not sure that what I have is in fact an me0709. I was just guessing it may be because it looks similar and the tag says 24-72v. Lol. All I really know is that it's the motor from a Tennant B7 floor burnisher. I have 2 of them and a bunch of other parts are on there. A 24v transaxle for one thing. I'm trying to think off something to use those for. There's also a pretty powerful linear actuator on there that I'm going to pull before I scrap the machines. Who knows what else I can scrounge up.


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## remy_martian (Feb 4, 2019)

If you wanted to be in that ballpark, why did you buy a 9hp motor?

Run the motor at its max continuous nameplate of 9hp and gear down appropriately. You're not running the pto, everything is towed, should be fine.


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## brian_ (Feb 7, 2017)

palmtree said:


> I don't know that I do. It was a 12hp gas tractor, so I thought I'd like to be on that ball park.
> What I know I don't want to do is spend the $ for a controller that's overkill.


The engine power rating is probably at a specific speed, and the tractor may operate the engine at a lower speed, so there may never be 12 horsepower available. I do understand wanting a surge current and torque capability, so a momentary load doesn't stall the motor.


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## palmtree (Jul 14, 2016)

remy_martian said:


> If you wanted to be in that ballpark, why did you buy a 9hp motor?
> 
> Run the motor at its max continuous nameplate of 9hp and gear down appropriately. You're not running the pto, everything is towed, should be fine.
> 
> Use BOTH...


Well I bought it because it was cheap and I'll likely do just as you say. I guess I don't need a controller over 200a then.


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## cricketo (Oct 4, 2018)

palmtree said:


> Ya I suppose that just because it looks like an me0709 and it's made for 24-72v, it doesn't mean that it is an me0709. I don't want to go overboard on the controller but I also don't want to limit the motor by the controller.


Note that the controllers from big brands typically call out their peak ratings, not the continuous ratings. So like for your application you will need something like a 300A controller.


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## palmtree (Jul 14, 2016)

cricketo said:


> Note that the controllers from big brands typically call out their peak ratings, not the continuous ratings. So like for your application you will need something like a 300A controller.


Okay. Do you think the Kelly kdz72301 would be a good fit.




__





Kelly KDZ Series/PM Motor Controller


DC Electrical, Electronic and Repairs



www.cloudelectric.com


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## cricketo (Oct 4, 2018)

palmtree said:


> Okay. Do you think the Kelly kdz72301 would be a good fit.
> 
> 
> 
> ...


Looks good to me, assuming you want regen and are happy with the voltage range. Is there any chance you will run the thing at a higher voltage in the future ? I think that motor won't be upset with 100V.


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## remy_martian (Feb 4, 2019)

...says the brush salesman 😂


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## palmtree (Jul 14, 2016)

cricketo said:


> Looks good to me, assuming you want regen and are happy with the voltage range. Is there any chance you will run the thing at a higher voltage in the future ? I think that motor won't be upset with 100V.


Hmm. I don't know. I picked 72v because I have a 40s Chevy volt battery left over from a solar storage project. Gives me 7.7 kwh as 20s2p battery. I could switch it to just a single 24s battery but then I'd only have 4.6 kwh with reduced run time. Actually hadn't even considered it. Maybe I should.


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## cricketo (Oct 4, 2018)

palmtree said:


> Hmm. I don't know. I picked 72v because I have a 40s Chevy volt battery left over from a solar storage project. Gives me 7.7 kwh as 20s2p battery. I could switch it to just a single 24s battery but then I'd only have 4.6 kwh with reduced run time. Actually hadn't even considered it. Maybe I should.


20s is 84V at full 4.2v per cell... You should also check what is the actual max voltage for the 72V Kelly controller.


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## palmtree (Jul 14, 2016)

Ya I figured I'd only charge to 4v for longevity. Still that's 80v but I figured the motor would be fine since most specs seem to revolve around lead acid voltage which would be 14.4 x 6 = 86.4 fully charged. I will need to check into the controller max voltage Thanks


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## floydr (Jun 21, 2021)

KDZ - Brushed DC Series/PM Motor Controller (12V-120V) (200A-550A) - Kelly Controls 72V 300A
• Configurable battery voltage range, B+. Max operating range: 18V to 90V.
• Motor Current Limit, 1 minute: 300A.
• Motor Current Limit, continuous: 120A.
later floyd


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## palmtree (Jul 14, 2016)

Thanks Floyd.


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## GregShay (Aug 20, 2016)

palmtree said:


> Well now I feel silly. My old jumper cables are apparently broken somewhere in there. I used a different set of cables and sparks flew and the shaft spun like a champ.
> Sorry I washed your time.
> Now to the spec label.
> It says 24-72v and 104 amps continuous duty. Do you think it will pull more current in bursts? I wonder because it says 8.8hp (max) which is about 72v at 104 amps. I'm trying to figure out which controller would work well but I dont want to spend more than necessary for an overkill controller. It's for a little tractor conversion.


Regarding pulling more current:
You can always put more current through a stalled motor, but you will burn it up. Max current is limited by the heat build up. This is why there are higher current ratings 'for 30 seconds' or the like.
Pay attention to cooling airflow where the motor is mounted. It has to be able to get rid of the considerable heat it will generate.
The max _continuous_ current rating is determined by the heat, and how fast it can get rid of the heat, not the wires or brushes.

Greg


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## cricketo (Oct 4, 2018)

GregShay said:


> The max _continuous_ current rating is determined by the heat, and how fast it can get rid of the heat, *not the wires or brushes*.


In the words from the Book of Wisdom, citation needed.


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## GregShay (Aug 20, 2016)

cricketo said:


> In the words from the Book of Wisdom, citation needed.


As you requested:








Continuous Duty Motor | Classes of Duty | Selection of Motor


There are two types of Continuous Duty Motor — continuous duty at constant load and continuous duty with variable load cycle. In the former the load torque remains constant for a sufficiently longer period.Classes of Duty-Continuous Duty,Short time duty,Intermittent Load Cycle



www.eeeguide.com


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## cricketo (Oct 4, 2018)

GregShay said:


> As you requested:
> 
> 
> 
> ...


I don't see where that page brings up the topic of brushes and internal wiring (besides the windings).


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