[brian_]

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.

 

[palmtree]

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.

 

[palmtree]

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.

 

[remy_martian]

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.

 

[brian_]

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.

 

[palmtree]

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.

 

[cricketo]

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.

 

[palmtree]

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 : Kelly KDZ Series/PM Motor Controller - Ship Today!

DC Electrical, Electronic and Repairs

www.cloudelectric.com

 

[cricketo]

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

KELLY-KDZ-SERIES : Kelly KDZ Series/PM Motor Controller - Ship Today!

DC Electrical, Electronic and Repairs

www.cloudelectric.com

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.

 

[remy_martian]

...says the brush salesman 😂

 

[palmtree]

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.

 

[cricketo]

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.

 

[palmtree]

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

 

[floydr]

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

 

[palmtree]

Thanks Floyd.

 

[GregShay]

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

 

[cricketo]

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.

 

[GregShay]

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

 

[cricketo]

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

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