[maquiza]

Hello,
Can a 15 Amps. cont. AC servo drive work with a 19 Amps. cont. AC servomotor? I think the answer is really simple, but I want to be shure.

Thanks,
Jorge

[Al_The_Man]

The current limit of the drive is probably going to limit the maximum current the motor is capable of, so the Current ( motor torque) output will be proportionally lower.
i.e. the motor will not be able to reach the maximum torque it is capable of.
Al.

[maquiza]

Al,

Please tell me if I am correct. The servo motor needs 19A to get a cont. stall of 13.3NM. The motor has a Motor torq constant Kt NM/A of .68. So if i use a 15 Amps cont. drive I get 15*.68= 10NM Cont. stall?
And if Peak stall of the servo motor is 27.36NM, what would it be with a 15A , 30A peak servo drive? Would the peak trq NM be 30*.68=20NM

I`m asking all this because I want to retrofit a Mazak Lathe. I already have one with dynapath and Baldors, But now I want to use drives and motors I have already and buy a Mazak Lathe with a death control.
The one that is retrofited have 6.5NM motors,with peak of 18.98NM; so If this work at 10Nm, with peak of 20NM, would be great.


Thanks,

Jorge

[Al_The_Man]

I have always considered the peak torque as not a usable torque value, this is generally the maximum current that would occur at the point of demagnetization.
So if you have drives set with a suitable current limit, your motors should ideally never see this figure.
You can calculate your constant torque as you show based on the Kt Nm/amp.
Al.