nema 23 heating up

[random837461]

Problem:

After connecting up my NEMA 23 stepper motor to a P70360 stepper driver and using MAX to start and stop the axis, the motor got hot and stayed hot (I turned of MAX then went to lunch and the motor was still hot).  Is the motor suppose to run hot?  Is there a turn off switch (besides powering down the driver) I was suppose to use?  Is my setup wrong?

Setup:

PXI-7334 connected to UMI-7774 using I/O Motion cable

UMI-7774 connected to P70360 Stepper Driver using control cable

P70360 Stepper Driver connected to NEMA 23 (T21NRLC) using Orange (A-), Black (A), Yellow (B-), Red (B)

NEMA 23 is powered by 120V AC power supply

P70360 Stepper Driver is set using DIP Switches (I tried to use the P7000 software tool that came with it, but it never found the driver):

S1: 1

S2-1: Off

S2-2: On

S2-3: On

S2-4: On

S2-5: Off

S2-6: Off

S2-7: Off

S2-8: Off

S2-9: Off

S2-10: On

S2-11: On

S2-9: Off

[Ever_Song · Accepted solution]

Hi,

First off, thanks for the thorough post and yes stepper motors run hot. Hot enough that you could not hold it in your hand for very long. This is normal. The way to keep it cool when not in use is by removing the power to the motor (by turning off the drive as you talked about).

[random837461]

Thanks

[Buechsenschuetz]

It depends on what you define as "hot". Temperatures around 35 deg C (sorry, I am German and not familiar with deg F) will be noticed as "quite hot" and around 40 deg C as "very hot". Both surface temperatures will not be harmful for stepper motors. 

If there is any risk of overheating electric devices, try to measure the surface temperature with an infrared thermometer. In most cases you will find that even "extremly hot" surfaces have not more than 50 deg C.  

[Valery_S]

What do you think about motor power drive NI P70530 and motor T21NRLH?  It has much smaller voltage pulses magnitude. Does the motor heat up more than author’s one?

[Buechsenschuetz]

Of course the heat dissipated by the motor depends on its efficiency and on the electric power supplied. The voltage drop across the motor winding depends on their dc resistance and the current supplied. So the amount of dissipated heat will always be the same with the same current applied to the motor. It does NOT depend on the supply voltage of the motor driver. 

Usually motor drivers are operated with 24VDC. Using a higher voltage will increase initial torque but, as mentioned, NOT the dissipated heat, since the latter rather depends on motor parameters when the coil current is given. 

[Valery_S]

Thank you. We faced this problem as the author. The temperaturе of our motor was about 75-80 deg C at the ambient temp 32 C! It is too high for our application! Unfortunately, we didn't know about this beforehand, and now we are looking for solution.