Fracomo Electromagnetic Wheel Lock

[Burgerman]

Ohms law says that the:
Resistance (R) = 34.3 ohm (Ω) so
Current (I) = 0.7 ampere (A)

So you can measure and test.

[FelipeOliveira]

Ohms law says that the:
Resistance (R) = 34.3 ohm (Ω) so
Current (I) = 0.7 ampere (A)

So you can measure and test.

Good morning Burgerman

Yes, the resistance is the same, but in this case, there is no resistance to be measured. Because it is definitely burnt out (Short Circuit)…

In the 3 scooters I received this month. And yesterday another one appeared!!! All with the same problem Electromagnetic brake burnt out

What if I replace it with another one with lower power (WATTS)?
What if the opening time is reduced? Or perhaps also reduce the acceleration, for a smoother exit??

[Burgerman]

A brake is on when no electrical power. It turns off when you move. Its like a cars hand brake. changing acceleration wont make any difference.

Brakes are either 12V or 24V and on/off. Thats it!

[shirley_hkg]

Is it strange a brake burnt out in all 3 scooters ?

These coils last.. Be aware that a 24V coil is not suppose to be fed at 24V all time. The controller should feed it 24V for less than a second , and switches to 12V immediately afterwards.

Looking at the size of the brake, it is hard to accept it can take 16w without heat dissipation measures.

[Burgerman]

These coils last.. Be aware that a 24V coil is not suppose to be fed at 24V all time. The controller should feed it 24V for less than a second , and switches to 12V immediately afterwards.

Some do this. Some dont. If its rated for 16 watts and 24V then it should be fine at 24V continuously.

[woodygb]

In the 3 scooters I received this month. And yesterday another one appeared!!! All with the same problem Electromagnetic brake burnt out

This suggests to me that these scooters have been supplied with a BAD batch of electromagnetic brakes .

Despite the brakes being marked as 24v 16.8 watts, I suspect that they are 12v 16.8? watts.

IF I am correct in my assumption , then the 12v coils... when fed 24v ...will get VERY hot as they would be consuming approx 75 watts.

Any chance of finding a scooter from the same batch , that has yet to develop this fault and then checking / testing a currently working brake?

[Burgerman]

This is why I did the ohms law stuff above. So he can easily test one. Obviously you cant test that once fried!

[FelipeOliveira]

Goodnight .
- test something that still works...
I'll find some, then I'll report the information
I have been listening to some colleagues talk about this issue for a long time,
But, until then, I had not yet worked on any
************************************************** ******
- incorrect marking on the part…
So far, in everything I've found about this brake. The specifications are the same;
I couldn't find exactly this specification on the manufacturer's website. I found it on aliexpress, Nithsdale Wheelchairs and Mobility Scooter Parts


PART CODE:
ALY0S6CC - AY670C05671

PART NUMBER – OTTOBOCK BRAZIL
511700-89800


Aliexpress :
https://a.aliexpress.com/_msju0hI

Nithsdale Wheelchairs :
https://www.nithsdale-wheelchairs.com/p ... b-653.html

Mobility Scooter Parts :
http://www.mobilityscooterpart.com/prod ... php?id=523

MANUFACTURER :
https://www.chaintail.com/aly0s4aa-powe ... lease.html

[woodygb]

The voltage being supplied to the 24v rated coils will not have exceeded that of the batteries ... so approx 24v... and thus should NOT have been a problem.

All that can be deduced from the photos is that the brake coil overheated , this caused the windings to short out and melt the wiring.

This happening on 3 or 4 similar scooters in a short window of time and suggests that a bad batch of brake coils where fitted in this particular shipment of mobility scooters.

I would contact Chaintail and complain / ask for an explanation of the failures.

[Burgerman]

May be caused by water or corrosion causing insulation break down.

TRY operating one at 10V and see if it FULLY releases and doesent fail or drag. If so, set the controller to 12V brake.

[FelipeOliveira]

May be caused by water or corrosion causing insulation break down.

TRY operating one at 10V and see if it FULLY releases and doesent fail or drag. If so, set the controller to 12V brake.

Good afternoon

This option was exactly one of the 2 I was thinking about, I will do it as soon as I have another one in hand.

The other option I thought of would be to replace it with a brake with lower power, for example, 8, 10 or 12 watts.

What do you think?

[Burgerman]

Runnin it at 12v does exactly that. IF it is still strong enough to reliably release the brake. Hence to test at 9 or 10 volts first.

[FelipeOliveira]

Goodnight

I just took the medications on both voltages, 12v and 24v, and with the 12v, it worked perfectly.

As the image below

I still intend to carry out tests installed on the scooter. But I didn't find where to change this parameter in PC Software WIZARD 5

Could anyone tell me what I could do and how to do it!


https://drive.google.com/file/d/10K_laS ... p=drivesdk

https://drive.google.com/file/d/1paYXjf ... p=drivesdk

https://drive.google.com/file/d/1-HZ-Rc ... p=drivesdk

[woodygb]

Your amps draw shows the problem.

Calculations from your readings give us ...assuming that I have done it all correctly.

2.1 Amps @ 13v = 6.2 Ohms and 27.3 WATTS .

5.4 Amps @ 25.9v = 4.8 ohms and 139.86 WATTS !!!! At this wattage your coil is a heater and will cook / melt.

I cannot find any programmer settings that allow a different voltage to be selected for the Rhino2.

Solution ... buy a 6 - 7 ohm high wattage resistor ... say 30 watts plus ... and wire it in series with your brake coil.

[FelipeOliveira]

Your amps draw shows the problem.

Calculations from your readings give us ...assuming that I have done it all correctly.

2.1 Amps @ 13v = 6.2 Ohms and 27.3 WATTS .

5.4 Amps @ 25.9v = 4.8 ohms and 139.86 WATTS !!!! At this wattage your coil is a heater and will cook / melt.

I cannot find any programmer settings that allow a different voltage to be selected for the Rhino2.

Solution ... buy a 6 - 7 ohm high wattage resistor ... say 30 watts plus ... and wire it in series with your brake coil.

[woodygb]

Ah!...my bad .

0.21 Amps @ 13v = 62 Ohms and 2.73 WATTS .

0.54 Amps @ 25.9v = 48 ohms and 13.986 WATTS.

IGNORE THE REST ...Neither reading seems to indicate a specific problem.

[FelipeOliveira]

I think we have to consider that this data was obtained with direct battery power.

I will still take the reading with voltage provided by rhino2 and the HS-559 scooter configuration parameters.

I have a question... for example:

If the scooter is used with low-charge batteries, . It will cause high consumption (Amperes), right? This also increases the power (Watts). And since there is nothing to dissipate this heat. Overheating is inevitable. Unless rhino2 is capable of managing it.

Am I talking nonsense?

Yesterday, I dismantled another one

[Burgerman]

Nonsense? Yes. Low battery voltage means less current.

[ex-Gooserider]

As mentioned, the brakes getting fed the wrong voltage can cause them to overheat and melt if they get excess current. If they don't get enough voltage, the brake may not release 100% and the friction drag from the brake not releasing fully will generate enough heat to damage both the brake AND the motor.

Note that the brake is ONLY intended as a 'parking brake' to keep the motor from turning (back-driving) when there is no power AND the scooter is not moving. It should release any time there is power to the motor, and only engage when the scooter is stopped and not getting power. (slowing and stopping is done with regenerative braking by the motor, NOT the brake!) The motor is more than strong enough to over-ride the brake, just like driving in your car with the parking brake on...

Another possible source of problems is if the brake is not fully releasing, possibly because of corrosion in the moving bits, or on the brake disk, or if the disk is warped, etc... Again this generates heat, and eventual failure...

ex-Gooserider

[FelipeOliveira]

As mentioned, the brakes getting fed the wrong voltage can cause them to overheat and melt if they get excess current. If they don't get enough voltage, the brake may not release 100% and the friction drag from the brake not releasing fully will generate enough heat to damage both the brake AND the motor.

Note that the brake is ONLY intended as a 'parking brake' to keep the motor from turning (back-driving) when there is no power AND the scooter is not moving. It should release any time there is power to the motor, and only engage when the scooter is stopped and not getting power. (slowing and stopping is done with regenerative braking by the motor, NOT the brake!) The motor is more than strong enough to over-ride the brake, just like driving in your car with the parking brake on...

Another possible source of problems is if the brake is not fully releasing, possibly because of corrosion in the moving bits, or on the brake disk, or if the disk is warped, etc... Again this generates heat, and eventual failure...

ex-Gooserider

Good morning!

I completely agree, and I know the function of the appliance brake, and also how it works…

What I don't understand, “IT LOOKS LIKE I'M NOT THE ONLY ONE AROUND HERE”, is what exactly could be causing this problem.
Today I was informed of another one, totaling 5 sooters, same model, same defect!!!

Does :

- suggest at all?
- BENDED DISC?
- Or is there really something wrong?

For anyone interested, here is the link to the video I received today from a friend

https://drive.google.com/file/d/1tALUV_ ... p=drivesdk


Shortly . As soon as the HD-559 scooter is here, I will take the readings, in full operation with the Rhino2

[Burgerman]

Possibly corrosion damaging insulation then shorted.

[FelipeOliveira]

Nonsense? Yes. Low battery voltage means less current.

Thank you for your kindness as always!!

I'm sorry if I expressed myself badly or incorrectly!!!

[Burgerman]

You didnt!

But as the voltage falls, the current also falls. So the most current and heat would be at the battery voltage when fully charged. Do they use salt on your roads? This is the only thing I can think of that might cause this.

[FelipeOliveira]

Hello

Here are the measurements made. By a friend. Even the results shown are not accurate, due to the quality of the equipment used. It is noted that the controller lowers the supply voltage of the electromagnetic brake keeping the 24v constant, and the same with the current, 66mA

[Burgerman]

Doesent sound enough I think? Could it be wrong?