RS485 Safety

[alanmccabe]

Hi All I am using an AXBB controller with an RS 485 adapter and the plugin from Dan911 to very successfully control my Huanyang VFD and spindle. It woks flawlessly, however always worry when I am changing a tool incase the spindle starts for some obscure reason. Is that possible and is there a way to prevent it with maybe a relay.

This is the controller
https://www.amazon.co.uk/gp/product/B01 ... UTF8&psc=1


ps I am not super technical so a simple explanation would be useful


Thanks in advance.
Alan

[ger21]

If you use a relay to start and stop the spindle, you can put a lockout switch in series with the relay. You can also wire a switch to an input on the VFD and set it to ESTOP.

[alanmccabe]

I dont have a relay on the spindle but the idea of the relay on estop sounds good I could put a relay on the wires running from the RS485 adapter to the VFD and then press estop when changing the tools. Thanks for that.
Regards ALan

[fixebr]

Hey!
I also wondered about such a question, and decided to use the VFD power outage scheme manually, button on my cabinet. I use a switch to supply the voltage to the power supply blocks of stepper motors and the rest of the electronics, and the double button (2 NO contacts with a green button and 2 nc contact with a red button) for VFD. Both switches - with state light bulbs so that I understand, they are ON or OFF. The main switch is 12 amp, in my case it is enough to supply meals for everything except the spindle (at least with a double reserve!). A double button can be any, as it serves meals only on the reel of the magnetic starter, and the current there is very small, but voltage is 220V.
Also, the magnetic starter is needed with an additional contact NO, and the beauty of the scheme is that after pressing the green button and the operation of the magnetic starter, the power current of the coil flows just according to the additional contact. Also, in this scheme, it is easy to install the relay in series with a red button, and for example, the relay on the Estop command - so the spindle will turn off when an accident.
The scheme is applied below.

[A_Camera]

I have a simpler, and in my opinion a safer solution, using a mechanical isolator, made for three phases and high current. No relays, no switching through any sofeware, just a flip of a lever up or down.



The isolator is wired between the VFD and the spindle. I switch it off every time my hands are inside the work area or when I am probing. It requires discipline, and I must remember to switch it on BEFORE the work starts, but that's fine for me, because it provides 100% protection against any accidents, which is the main thing.

BTW, I am not using Dan's plugin, but controlling my spindle entirely with Modbus and RS485 through the plugin provided by UCCNC and my own macros.

[alanmccabe]

Thanks all, some food for thought I like that simple 3 phase switch idea though A_Camera

[Vmax549]

Before you do the 3 phase switch idea check in your manual about a warning to NOT install a switch between the VFD and motor. MOST have that warning.

Just a thought, (;-) TP

[fixebr]

+1
A cliff of one or more cables between the motor and the VFD will lead to the combustion of the VFD keys.
If you really make the chain rupture, then on the VFD power line.

[ger21]

It's safe if you don't switch it while the spindle is running. If you switch it with the spindle running, you destroy the VFD. That's why there's a warning.
I've used an industrial router with one VFD running two separate spindles independently, and the Yaskawa VFD output was switched with contactors.

[Vmax549]

YES it can be switched between motors but you use a sequence know as make before break. That means you make the AUX connection before you break the Main connection. That way there is never an open connection. It only takes 1 OOPS to blow out the final drive of a VFD.

That is my advice, your mileage may vary due to local driving conditions.

Just a thought , (;-) TP