{"id":182828,"date":"2015-05-29T19:59:00","date_gmt":"2015-05-30T00:59:00","guid":{"rendered":"https:\/\/www.panix.com\/~msaroff\/40years\/2015\/05\/29\/run-away-from-these-people\/"},"modified":"2015-05-29T19:59:00","modified_gmt":"2015-05-30T00:59:00","slug":"run-away-from-these-people","status":"publish","type":"post","link":"https:\/\/www.panix.com\/~msaroff\/40years\/2015\/05\/29\/run-away-from-these-people\/","title":{"rendered":"Run Away from These People"},"content":{"rendered":"

On a web site dedicated to people who do consumer electrical work, someone posits that Tesla’s new home battery packs will force homes to go voltage DC current<\/a>. This is absolutely and completely wrong, because fails to get even a single fact right, as would be clear to anyone who knew the most basic physics:<\/p>\n

CE pros might be sitting in the proverbial catbird seat when it comes to the future of wiring homes.<\/span>

<\/span> With the solar revolution seemingly in full swing all across the nation, consumers are enamored with \u201cgoing off the grid.\u201d And many homeowners are counting on home batteries to be the next phase of their off-the-grid plans. Companies likes Tesla and RoseWater Energy Group are leading the way in the development of these new power storage devices for homes.<\/span>

<\/span> But if the battery power trend takes off, it must lead to a new paradigm in which homes will be powered more with low voltage wiring than line voltage electrical, according to a blog by CE veteran Paul Self on Buildz.com<\/a>. <\/span>

<\/span> Indeed, will the pure science limitations of AC\/DC conversion eventually force a gigantic sea change from builders, electricians and the National Electric Code itself in the way homes are constructed and wired? The answer is \u201cYes\u201d that might have to happen, says Self.<\/span>

Here is Self\u2019s logic:<\/span> [Or more accurately, here are his completely incoherent thoughts]<\/p>\n

\u201cAn underlying issue with solar power and the Tesla battery is the fact that they run on DC while the power infrastructure in buildings is AC. Stepping power up and down from AC to DC and vice-versa wastes energy, about 20 percent is lost in the conversion. Some converters do a better job than others, but resolving this 20 percent loss is very important when working on a battery stored energy supply.<\/span><\/p><\/blockquote>\n<\/blockquote>\n

Ummmm. No. Inverters operate at efficiencies of about 95% at their design points, and if you are connected to the grid, as Tesla envisions, you will only use the inverter . <\/p>\n

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Many devices in a home could run on DC. Almost all non-incandescent light bulbs can run on DC and require a transformer to step the 110 VAC down to a 12 \u2013 5 VDC signal for the bulb. <\/span><\/p><\/blockquote>\n<\/blockquote>\n

No. The a fluorescent light ballast operates as follows: It uses a transformer to jump UP the voltage (not down), then rectifies it to DC, and then uses an inverter (square wave, because unlike motors, that is fine for gas tubes) to hop the frequency from 60hz in the wall, to 1+ Khz to eliminate flicker.  (For incandescents, it’s not an issue, because even as the AC current goes through them they hot.  CFLs are generating lights from individual sparks).<\/p>\n

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Other devices like computers, TVs, cable boxes, and cell phone chargers all operate similarly.<\/span><\/p><\/blockquote>\n<\/blockquote>\n

No again. They cannot use line current, they need to condition the power, and it is easier to do this with AC current.<\/p>\n

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Appliances like electric ovens, electric water heaters, and air conditioners will require 110VAC, but most of the house is on DC.<\/span>
Let me paint you a picture.<\/span><\/p><\/blockquote>\n<\/blockquote>\n

They reacquire 110VAC because they are high power, and at low voltage, the amperage, and wire size go through the roof. (Details follow)<\/p>\n

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