Wheelchair motor specs

[cowana]

I have a wheelchair motor, of which I am trying to find more about. From the lable on the motor (my comments in green):

FRACMO
REF 451-50-041-B34-29A
SER. No 103072/   18
A  10.9                                 [COLOR="Green"]I would guess this is the current, but which? Stalled? No load?[/COLOR]
Volts 22.5MTR/12BR                      [COLOR="Green"]22.5v? That seems like an odd value for a wheelchair - I'd have guessed 12v or 24v...[/COLOR]
Hz DC                                   [COLOR="Green"]Obvious.[/COLOR]
Ph                                      [COLOR="Green"]No phase, as it is DC[/COLOR]
RPM 117                                 [COLOR="Green"]Obvious[/COLOR]
o/p 11.0NM                              [COLOR="Green"]Torque, seems about right[/COLOR]
RTG CONT                                [COLOR="Green"]Continuous rotation?[/COLOR]
INSUL F                                 [COLOR="Green"]Something to do with insulation?[/COLOR]
IP 44                                   [COLOR="Green"]Obvious - waterproof.[/COLOR]
DATE ML                                 [COLOR="Green"]Manufacture date?[/COLOR]

The brake releases at 6v, and the motor will run happily from 12v down to 2v (drawing about 2A at 12v, no load). I haven't tried a higher voltage.

Any thoughts on further decoding this data?

 

[MikeMl]

My mother used a "made in china" mobility scooter that had a similar motor. The unit had two 12V SLAs (in-series), so the motor (and everything else ran on a nominal 24V. The Motor current was PWMed; and it had dynamic braking. Based on the battery life vs AH rating of the batteries, the motor, while having a stall current of 10A, must have only pulled ~2A or less, most of the time...

 

[Sceadwian]

Amps listed on motors are usually running no load, I don't think I've ever seen one that has a rated stall current, but that's easy to determine by measuring the resistance of the motor coil.
It looks like it's meant for 24 volts, even though the brake release operates at 6 volts I'm guessing the 12BR means that it was meant to be run at 12 volts, I don't think you want your brake slipping or dragging if you hit bumps, so I'd verify that. So it looks like the one you have has quiet a bit more kick than the one on Mike's Mom's mobility scooter, those things are much lighter than a true motorized wheelchair. My dad has one as well (scooter)

RTG meaning rating. IE it's meant for continuous usage.

The F is the insulation rating.
NEMA Insulation Classes

Basically the motor is built like a tank for 24 volt operation. You could probably add 25-50% voltage (with a comensurate increase in current) if the run time will be short, it's mostly thermally limited. If you run it at 24 volts you can do just about anything but stall it for extended periods of time without hurting it.

 

[Reloadron]

They have a website but I couldn't find that motor, even under mobility. May be able to email them with what you have and get a pdf on the motor.

Ron

 

[cowana]

Volts 22.5MTR/12BR

Of course - 22.5v motor, and 12v brake. I was originally thicking 'meters', which was confusing me.

I hope no load current @24v isn't over 10A - that's a lot for two motors!

No load current @12v: 3.2A
No load current @19v: 4.0A (19v is the maximum my power supply goes to)

Coil resistance: 0.7R (measured with my 87V's probes compensated for)
Calculated stall current: 35A (lower than I'd expect)

Thanks for all your help.

 

[Mr RB]

The 10.9 amps will be a full-load value. Probably 22v @ 10.9A.

As MikeMl said they are designed to run from 24v battery and a PWM controller.

 

[Sceadwian]

What does full load value mean? It has to be measured at a specific output torque and RPM to mean anything.

Does that mean at 117 RPM with a torque delivery of 11 newton\meters the current will be 10 amps? That makes sense then. By my calculations that's 8.1lb/feet of torque. The current will go up pretty fast if the output shaft is loaded beyond that. From a dead stop you're looking at some pretty serious starting currents.

 

[Mr RB]

Usually they are rated as a max power spec, ie a 200W wheelchair motor or a 300W wheelchair motor etc. So it's probably 22.5v 10.9A ie a 250W motor.

The RPM value is probably no load, but that is very easy to test with a tacho anyway.

The torque value could be a stall torque at 22.5v or it could be torque at full load ie 22.5v 10.9A.
11 NM is 112 kg-cm which is a bit high to easily test, I'm guessing it might be a stall torque.