EPAIII
Diamond
- Joined
- Nov 23, 2003
- Location
- Beaumont, TX, USA
This is for those who are well acquainted with the NEC. I want the official poop, not just some guesses.
In building a circuit that uses lower Voltages, probably a DC supply of some sort and housing it in standard electrical boxes which would be attached to either the building or to equipment in it, what would be the code's requirements for isolation of the low Voltage wiring vs. the line Voltage. It is my understanding that they should not be in the same box or conduit. But I could be wrong.
Now I know that electronic devices are routinely built with AC power being brought into an enclosed chassis that also has the lower Voltage electronics inside it. It is usually routed to a power switch, fuse holder, and transformer with wires that are as short as possible. And there is no objection to this in the NEC. But what happens if the low Voltage circuit (the electronics) is to be housed in a standard electrical box.
I built one such circuit once. I used a transformer which mounted in a knock-out hole and the line connections were passed through that hole. So the power was in one box and the low Voltage wiring was in a second one that was attached along side of it. The line connections passed through the aligned holes in the two. Was this OK?
And what does the NEC say about running 115 or 230 Volt power in the same conduit as perhaps a 24VDC or even a cable with logic level signal? Is this ever permitted?
In building a circuit that uses lower Voltages, probably a DC supply of some sort and housing it in standard electrical boxes which would be attached to either the building or to equipment in it, what would be the code's requirements for isolation of the low Voltage wiring vs. the line Voltage. It is my understanding that they should not be in the same box or conduit. But I could be wrong.
Now I know that electronic devices are routinely built with AC power being brought into an enclosed chassis that also has the lower Voltage electronics inside it. It is usually routed to a power switch, fuse holder, and transformer with wires that are as short as possible. And there is no objection to this in the NEC. But what happens if the low Voltage circuit (the electronics) is to be housed in a standard electrical box.
I built one such circuit once. I used a transformer which mounted in a knock-out hole and the line connections were passed through that hole. So the power was in one box and the low Voltage wiring was in a second one that was attached along side of it. The line connections passed through the aligned holes in the two. Was this OK?
And what does the NEC say about running 115 or 230 Volt power in the same conduit as perhaps a 24VDC or even a cable with logic level signal? Is this ever permitted?