The only two energy resources we're really tapping for this house are natural gas and electric power, but provided here by the local utilities, SCE&G for gas. and Aiken Electric Cooperative for power.
Like most residences here, we are getting single-phase service. Most homes here get 20 KVA feeds. (We need to double check this: 20 KVA is 16 Kilowatts but it may possibly be a 20 KW feed; we don't foresee needing that full capacity).200-Amp service may be enough.
Surge protection is a critical factor, and we will have an Eaton whole-house surge protector at the breaker box. Most wiring will go through Atkore steel conduit, which also eliminates some causes of surges. Signal lines (cable, phone, etc.) entering the house will also run through surge protectors, preventing “back door” surge sources.
A Cummins generator (fueled by natural gas) will provide backup power. It won't be working alone.
CyberPower and Tripp-lite products provide always-on (also known as continuous-online double-conversion) true sinewave power for critical systems. This avoids problems when the power switches back from the generator to again being utility-supplied and is compatible with even the most finicky computer systems.
A surprising number of traditional power points in the house will not be connected to AC power at all. These devices are, for the most part, designed to work with batteries. We'll feed them a different way. Does the box on the left look familiar? It's typical of an ATX PSU, the power supply units found inside most desktop PCs. It provides clean and regulated DC power at 3.3, 5 and 12 Volts. The unit on the right is a CyberPower line-interactive sinewave UPS. At various locations around the house, mostly in the attic or the crawl space, we can set up the UPS, plug in the PSU and populate a second run of steel conduit with lines carrying the DC power feeds to our automation gear.
Credit old friend Al Roberts for confirming our selection of 14 gauge wire as the best choice for carrying these DC feeds, based on the Voltage and the probable current draw. We also spoke about the best way to tap the bus run to deliver the various power feeds. We discussed the trade-offs of several approaches (like crimp-on connections and taps, wire nuts and soldering); one concern is that any connection can become vulnerable to aging through oxidation or other mechanisms. Also, any effective reduction of the wire diameter can add path resistance, which may drop the Voltage on the line. Al suggested adding an electrolytic capacitor at the far end of each feed; it will store the highest Voltage that it's been fed and act as a buffer, buoying the line if too many devices seek too much current at once. In this application, 1000 microfarads is enough, a 50-Volt capacitor that sees no more than 12 Volts provides additional survivability and longevity, as does specifying a higher operating temperature tolerance.
LED lighting fixtures also run on DC, but in their case, a device called a driver connects to nearby AC power.
As we mentioned, a lot of places that usually see AC power connections in most homes don't see them here.
The switches on the wall are actually low-power Bluetooth Smart Mesh devices from Aircable’ automation decodes presses or taps on them into instructions for the Synapse Wireless lighting control system, for the ceiling fan control relays in the CAP modules and so on.
Most switch locations (in the usual and expected place, just inside a door) will have a 3-gang electrical box with one switch nominally for lighting, one nominally for ceiling fans and one seemingly in reserve. Engineers would refer to these as software-defined switches.
For starters, the light switch could respond to a tap to turn on or off and a press-hold to dim. Later, multiple taps could have a special meaning; for example, 5 taps might signal that guests are expected in a room that's been vacant.
The room will have power outlets, of course, including USB power outlets. We don't plan to control any of those outlets; it can be confusing when an outlet doesn't deliver power.
Heating, most cooking appliances, hot water heat, clothes drying, the fireplace and the backup generator are the energy endpoints for the natural gas feed to the house.
Can't think of anything else to say about that for the moment, but no doubt something will come to mind later.
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