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Considering that most electronics run off DC and PV cells output DC, why not run a DC distribution bus in certain areas like a home theater, ham shack, or computer closet? Especially if you have PV cells or other power generation on-site or an electric car charging station.

I am aware that DC doesn't like long runs without very large conductors, but if the runs can be kept short...

Think about it: instead of dozens of wall warts and converters for electronic devices, each with its own efficiency loss, heat generation, and cable management problem, you could simply plug those things into something like a Powerpole system.

Thoughts?
 

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Thoughts.
It would be fine if they ran off the same DC voltage. But the thing you mentioned could be anywhere from 5 volts(wall warts) to 120 volts or higher(electric car). DC does not convert like AC with a simple transformer.
It works well in travel trailers and boats where everything is 12 or 24 volts.
 

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I have installed countless DC distribution busses, from 24 VDC - 540 VDC.

None of them for residential distribution, all commercial - telco, UPS and network distribution.
 

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I have done this for security camera systems to have battery backup. There may be dozens of security cameras which run off of 12 VDC. So just a matter of placing an AC to DC power supply / battery charge controller in a large enclosure (like for an alarm panel), then using "barrier strips" and wires with spade lugs to connect all the wires.

Solar electric systems use 12 VDC charge controllers.







 

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i would not use that cheap chinese power supply with probably no protection at all inside, also you must fuse every wire since they cant deliver 33A without overheating
 

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Discussion Starter #7
Thoughts.
It would be fine if they ran off the same DC voltage. But the thing you mentioned could be anywhere from 5 volts(wall warts) to 120 volts or higher(electric car). DC does not convert like AC with a simple transformer.
It works well in travel trailers and boats where everything is 12 or 24 volts.
Yes, I recognize this as a complication, but exactly how complicated is uncertain until I assemble a list of all the devices that I would connect and see if there are any natural clumps around common voltages. Most ham radio gear is 12V, so I would definitely start with a 12V bus in my radio room.

I'm curious about integrating the DC bus into the building's main power supply and grounding/bonding system. Also curious on how to sell such an idea to the city residential permit office, which will probably start from the default position of "it can't be done" (yes it can, per NFPA 70 & FL code).
 

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I'm sure it can be in addition to all the required 120volt AC circuits. I don't think you could wire a building 100% DC under current code.
 

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Considering that most electronics run off DC and PV cells output DC, why not run a DC distribution bus in certain areas like a home theater, ham shack, or computer closet? Especially if you have PV cells or other power generation on-site or an electric car charging station.

I am aware that DC doesn't like long runs without very large conductors, but if the runs can be kept short...

Think about it: instead of dozens of wall warts and converters for electronic devices, each with its own efficiency loss, heat generation, and cable management problem, you could simply plug those things into something like a Powerpole system.

Thoughts?
I'm sure it can be in addition to all the required 120volt AC circuits. I don't think you could wire a building 100% DC under current code.
joed, your post is interesting and I am sure that the OP had a legitimate question, which is not entirely answered by your comment.

In my own home I have a "situation" where I have an alarm system and an emergency lighting system, both powered by a 12 V battery "on float".
That battery is capable of supplying a large number of amperes but the current supplied to any of the house wiring is limited via fuses appropriate to the gauge of the conductors supplying the load and the insulation over those conductors is appropriate to the (higher) voltage of any adjacent conductors - according to the local rules.

It is not that "100% DC wiring of a building" may be under consideration (as Edison may have wished) but appropriate current limitations on conductors, of whatever gauge, and voltage requirements on insulation between them must be observed, as they are in "normal" domestic/industrial installations between "Low" and "Extra Low" voltages.
 

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The point I was trying to make is that in a home you are required to have certain circuits. Some of those would be receptacles every 6/12 feet along a wall, Kitchen counter small appliance branch circuits.

Dc circuits would of course need to be used properly. I can only assume the same rating as AC would apply, 15 amps on #14 wires 20 amps on #12 etc.
 

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Discussion Starter #11
It is not that "100% DC wiring of a building" may be under consideration (as Edison may have wished).
Correct, I am not trying to replace AC with DC across the whole building. I only want to experiment with the potential energy savings, heat dissipation, and cable management benefits of using a centralized, high-quality AC-DC converter and supply those rooms that will be filled with electronics (i.e., radio room, IT closet, and home theater/studio).

Also, it was Tesla who preferred DC. Edison got his wish through some very underhanded tricks.
The point I was trying to make is that in a home you are required to have certain circuits. Some of those would be receptacles every 6/12 feet along a wall, Kitchen counter small appliance branch circuits.

DC circuits would of course need to be used properly. I can only assume the same rating as AC would apply, 15 amps on #14 wires 20 amps on #12 etc.
The common rules about AC are irrelevant to my intent for this thread. AC bus will not be impacted by my idea, except for 2 possible ways (if I'm missing something, please clue me in):
1. The connection of the central AC-DC converter at the main panel or a subpanel somewhere.
2. The grounding/bonding of the DC bus to a common, single-point equipotential ground system for the whole house (my system can't tolerate ground loops).

Conductor sizing would of course be appropriate to the demand and distance, but it doesn't correspond to the AC conductor rules. The smallest conductors will probably be 8 or 10AWG from the socket to the device. The bus will be in the "aughts". DC needs big cables. Or a busway....
 
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