Hello all,
I started to wire my e-stop circuit which will handle my 4 axis setup and just wanted to share my ideas and see your opinion on whether this will work or not.
So I have a 24V relay that is energized through all the E-stop buttons, limit switches and the charge pump from the computer. When I have a normal condition the relay is switched ON. A NC contact on the relay is wired from the UHU E-STOP IN pin through a diode to ground. All 4 UHU's are wired in a loop, so one's OUT pin goes to other's IN pin. This halts all the boards when a single one errors.
Another pin from the relay is used to energize a magnetic contactor, which puts resistive load directly on the motor leads. When the contactor is switched ON the resistors are disconnected from the outputs.
Another contactor which switches the primary of the power supply is also wired to the E-stop relay. When it is OFF it cuts the primary and puts a load on the capacitor bank. So far so good.
My question is, I know that when the UHU chip is on red /the error led is ON/ the output pulses are cut, and the motor is let to spin free till it stops. Can I safely put this load resistors on the output without damaging the drive, and eventually stop the motor fast enough? My motors accept 100A peak current, so with a power supply of 65V and full speed if I put 2 Ohm resistors on the leads it gives something like 32.5A in the first moment and descending after that.
In my understanding, there should be no problem to do this but I wanted to be sure before I blow some FET's.
Sorry for the text explanation, I will try to draw a schematic of this later to be more specific.
Thanks, Todor
EDIT: I am using the OLD UHU if this matters.