Andrey's UHU HP

[Andrey67]

Today has finished installation UHU HP on my machine tool. It works! I am very happy!

[contactirfu]

Congrats Andrey - another feather to the cap!

nice looking heatsinks - and a very compact setup!

have fun!

[Andrey67]

I have a question. The motors heat up to 50 degrees of Celsius in 30 minutes. It is possible to struggle somehow with this problem? Motors are presented on a photos.

[contactirfu]

First thing is this a problem at all?

after 3 hrs - my motors are hot - though not exactly measured the temperature - but still hot.

I think you can try by limiting the current - in my case I have more current flowing in than required.

if possible chk with a clamp meter the current which is drawn here.

also does your UHU heatsink get hot?

RGDS
IRfan

[H.O]

50 degrees celcius shouldnt be a problem, If it stabalizes there I wouldn't worry about it. What's the Vref on the HP-UHU board set to? It looks like the plate on the motor says 9.5A so you should set Vref to around 95mV.

If the motor has very low inductance the larger ripple current might contribute to the heating. Adding an external inductor to smooth the current might help but will affect the performance of the motor slightly.

But again, personally I wouldn't worry about the motors getting 50°C. For reference the datasheet for my motors specs a 50°C rise when operating at it's continuos rating (ie. 70°C case temperature at 20°C ambient).

/Henrik.

[Andrey67]

Irfan and Henrik, thanks for answers!
I do not know temperature will increase further. I worry for encoders HEDL-5640#A06! Unfortunately I have not measured temperature UHU heatsink! Vref precisely to measure it was not presented possible. Voltmeter indications not constants. Figures constantly "jump". Exposed an experiment method while work of motors did not become smooth and stable. Can motors not are intended for long work? Can to me cooling by fans will help?

[H.O]

Hi Andrey,
If Vref is not stable there's something wrong with the board, your setup or the instrument you're using to measure Vref.

Power up the logic supply for the board (15V) but leave the motor powersupply turned off or disconnected from the HP-UHU. Set your instrument to measure DC-voltage (200mV range if it has one) and connect the black lead to GND of the incoming logic power, then connect the positive lead to the Vref test-point on the PCB, next to trim-pot. The voltage must be stable and adjustable with the trim-pot, set it to around 95mV.

Forced air cooling of the motors will help with the temperature but if the current limit circuit on the board doesn't work then you're in trouble. Make sure you get a stable Vref so you can set the current limit to what the motor is rated for.

What is your motor powersupply voltage?

/Henrik.

[Andrey67]

Hi, Henrik!

I spent measurements as you write. But tomorrow I will try once again. When motors have been established on the machine tool, axis Z did not move upwards. I rotated VR16 while axis Z has not begun movement. On other axes VR16 it is established in average position.
72V is my motor powersupply voltage.
Andrey.

[Andrey67]

Today has made more detailed measurements of temperature. Environment +25С, in 60 minutes motors have heated up to +47-50С. The radiator on IRFP264 has heated up to +35-37С. Vref precisely to measure there is no possibility (I can not load video!). On a photo the motor in the form of parts. The motor because of design features can be heated?

[H.O]

Hi,
Can't say about the design of the motor but if you only get a 25° temperature rise over one hour I wouldn't worry about it - 50°C is no problem for a motor like that. I found a datasheet for your encoder and it specifies either 70°C or 100°C operating temeprature depending on the the specific type of encoder so again, 50° shouldn't be any problem at all.

What worries me is that you can't get a stable reading on the reference voltage, I'd look into that a bit more if I where you....

[jcdammeyer]

What amazes me is how little windings there are.
John

[Andrey67]

Hi!
So voltmeter indications when I measure Vref vary.

YouTube - Video

YouTube - Video