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Brushless Motor 660watts/48 Volts


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#1 Claudio

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Posted 02 September 2007 - 08:58 PM

Hello All,

I am using a brushless motor with a 48Volts driver. I am using a power supply of 24 Volts and without smoothing, so I'm getting a high ripple.

I am using 24 Volts, so I will have 1/2 of the power disposal.

The maximum continuos current in the driver is 25A, and the max continuos current in the motor is 19 A.

The motor is driving a hidraulic pump.


The problem:
When I run the motor in 24 Volts, the current is about 15A. Everything looks OK!, but the three wires from the driver that supplies the motor gets very hot and I need to turn out the motor.

Can somebody help me?

#2 mariomaggi

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Posted 03 September 2007 - 06:33 AM

Dear Claudio,
is your motor running properly without vibrations?
Probably your feedback device is not mounted in the right angular position.

Some brushless motors are specified at very high temperature, over 200C, therefore windings are very hot and also external wires are hot, being thermally connected to windings.

Kindest regards
Mario

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#3 Claudio

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Posted 03 September 2007 - 10:37 AM

QUOTE(mariomaggi @ Sep 3 2007, 10:03 AM) View Post

Dear Claudio,
is your motor running properly without vibrations?
Probably your feedback device is not mounted in the right angular position.

Some brushless motors are specified at very high temperature, over 200C, therefore windings are very hot and also external wires are hot, being thermally connected to windings.

Kindest regards
Mario



Dear Mario,

Thank you for your help!!

Yes, my motor is running properly and without vibrantions.

The insulation class is "B". In fact I consulted a table, and I could see that the coil temperatura can support until 100 C for 100.000 hrs life.
I will test the motor and measure the temperature of the wire.

Thanks.
Regards,

Claudio

#4 marke

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Posted 03 September 2007 - 10:58 AM

If the wires between the driver and the motor are very hot, I would suggest that you increase their size.
Larger wire, lower temperature rise.
What size wire are you using??

Best regards,

#5 Claudio

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Posted 03 September 2007 - 11:04 AM

QUOTE(marke @ Sep 3 2007, 02:28 PM) View Post

If the wires between the driver and the motor are very hot, I would suggest that you increase their size.
Larger wire, lower temperature rise.
What size wire are you using??

Best regards,


Dear marke,

These wires are the wires that came from inside the motor - 20 AWG.
Thanks
Regards,

Claudio

#6 marke

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Posted 03 September 2007 - 11:19 AM

Hello Claudio

If this is the winding wire from inside the motor, then yes it will run pretty hot. It will be sized and rated to run up around 100C or may be even more. You should probably terminate these wires onto much heavier wires, or large terminals to help take some of the heat away.

Best regards,

#7 Claudio

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Posted 03 September 2007 - 12:23 PM

Dear marke,

Thanks. I will run the motor and admnistration the temperature.

Best Regards,

Claudio

#8 Claudio

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Posted 04 September 2007 - 12:56 AM

Dear Sirs,

I ran the motor and the wires temperature was about 55C (I thought this temperature was very hot to the wires) and the room temperature was about 30C.

I do not have problems.

Thanks,

Regards,

Claudio

#9 mariomaggi

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Posted 04 September 2007 - 10:26 AM

Claudio,
QUOTE
wires temperature was about 55C (I thought this temperature was very hot to the wires)


no, this temperature is absolutely normal and safe. Don't worry!

Regards
Mario

Mario Maggi - Italy - http://www.evlist.ithttps://www.axu.it





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