alive15
Member
Hello all,
We have an electrical cabinet which powers an okuma machining center (OMC) and also includes i/o module for robot. All devices related to OMC is powered from 480V, which is stepped down to 120V (NPN), which is then stepped down to 24V (NPN). The main breaker / disconnect is tied to the 480V 3 phase coming in.
Looks like few years down the line, they added a fanuc robot in front of the machine, so it was necessary to install an i/o module inside the same cabinet. However, for some reason, this was wired using PNP setup. So someone added a separate 120V power supply inside the cabinet, which is then stepped down to 24V pnp. The 120V is not connected to any switch / breaker, there are only fuses. It is actually coming from a power outlet next to the machine.
From my understanding, the idea was, in case the OMC went down, the robot i/o module was still powered on, and the robot could still run.
My task is to eliminate the safety issue where if someone turns the breaker off, they may assume there is no power in the machine, when actually there is still 120V / 24V pnp for the robot i/o module.
So I have figured out the wiring, and I can re-wire the robot module circuit to get fed by the original 480V coming in, so everything inside the panel would be tied to the OMC main breaker, but would lose the advantage of having the robot running in case the machine goes down.
Is it considered good practice for me to add a plexi-glass covering with holes around the robot i/o module power supply, and maybe change the wire colors to "orange" to showcase that power is still inside the machine, even though the main breaker is off? I want to figure out a way to keep the robot alive, even if the OMC breaker is turned off. I don't want to create a separate panel / junction box just for the robot i/o module power.
The reason I have recommended this idea, is I have seen something similar on different machine, were they used orange cable to denote power was still on the machine (it was backup battery for computer)
Any ideas are appreciated. Thanks,
We have an electrical cabinet which powers an okuma machining center (OMC) and also includes i/o module for robot. All devices related to OMC is powered from 480V, which is stepped down to 120V (NPN), which is then stepped down to 24V (NPN). The main breaker / disconnect is tied to the 480V 3 phase coming in.
Looks like few years down the line, they added a fanuc robot in front of the machine, so it was necessary to install an i/o module inside the same cabinet. However, for some reason, this was wired using PNP setup. So someone added a separate 120V power supply inside the cabinet, which is then stepped down to 24V pnp. The 120V is not connected to any switch / breaker, there are only fuses. It is actually coming from a power outlet next to the machine.
From my understanding, the idea was, in case the OMC went down, the robot i/o module was still powered on, and the robot could still run.
My task is to eliminate the safety issue where if someone turns the breaker off, they may assume there is no power in the machine, when actually there is still 120V / 24V pnp for the robot i/o module.
So I have figured out the wiring, and I can re-wire the robot module circuit to get fed by the original 480V coming in, so everything inside the panel would be tied to the OMC main breaker, but would lose the advantage of having the robot running in case the machine goes down.
Is it considered good practice for me to add a plexi-glass covering with holes around the robot i/o module power supply, and maybe change the wire colors to "orange" to showcase that power is still inside the machine, even though the main breaker is off? I want to figure out a way to keep the robot alive, even if the OMC breaker is turned off. I don't want to create a separate panel / junction box just for the robot i/o module power.
The reason I have recommended this idea, is I have seen something similar on different machine, were they used orange cable to denote power was still on the machine (it was backup battery for computer)
Any ideas are appreciated. Thanks,