Why a Typical Home Solar Setup Does Not Work with the Grid Down

Re:Why a Typical Home Solar Setup Does Not Work with the Gri... by alkonaut on Thursday August 02, 2018 @05:10AM (#17670174)

When I work on electrical wires at home, I test if they are hot after flipping what I believe is the correct fuse. If I’m right I know it won’t become hot while I work on it because I control the switches and fuses.

If I worked on wires where I was not in control of incoming power, then I can not be sure the wire isn’t hot just because I measured once. This is for example the case when working with stuff with big capacitors.

So my point is: can line workers really assume a wire isn’t hot just because they tested it? They don’t control both ends, since as you pointed out, anyone could have a) a power source or b) a faulty connection, whether it’s allowed or not. So as a line worker I’d basically just not touch anything even in supposedly dead grid sections.

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Re:Why a Typical Home Solar Setup Does Not Work with the Gri... by zaarn on Thursday August 02, 2018 @09:03AM (#17671071)

I recommend shorting to ground. Even if it's your own fuse. Shorting means that if you picked the wrong fuse you notice. And when your friend comes by and flips the fuse back on you don't get a spark shower (something like this has happened to me, don't underestimate people willing to flip fuses for no reason)

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Re:Why a Typical Home Solar Setup Does Not Work with the Gri... by wlesieutre on Thursday August 02, 2018 @09:38AM (#17671259)

A common solution for this is lockout-tagout, where you physically lock the breaker open using a lock with your name on it, and nobody can flip it until you come back and take the lock off.

Used on electrical circuits as well as dangerous machines if you need to climb inside a compactor for maintenance or something.

https://www.osha.gov/Publications/3120.html

http://www.deenergize.com/?target=Universal_Circuit_Breaker_...

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Re:Why a Typical Home Solar Setup Does Not Work with the Gri... by zaarn on Thursday August 02, 2018 @09:51AM (#17671342)

That works too, though IIRC the common procedure in the industry in my country is to use a warning label/shield and hang it on the breaker box during repairs, locking the breaker box itself, then short out the circuit to ground and measure to be sure.

Locks on the breaker itself are more rare (usually for low voltage repairs where the common person might frequent the area)

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Re:Why a Typical Home Solar Setup Does Not Work with the Gri... by crististm on Thursday August 02, 2018 @07:17AM (#17670612)

When they work on train power lines, what they do is physically short them to the tracks.

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Re:Why a Typical Home Solar Setup Does Not Work with the Gri... by Cerium on Thursday August 02, 2018 @12:04PM (#17672532)

You should test if they are hot before you flip the breaker, then test again after. If you only test after you are not protected against faulty test equipment or improper wiring.

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Re:Why a Typical Home Solar Setup Does Not Work with the Gri... by alkonaut on Thursday August 02, 2018 @12:47PM (#17672977)

Yes. This was assuming the light was shining (or equiv, that it showed 230V) before work starts of course.

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Re:Why a Typical Home Solar Setup Does Not Work with the Gri... by VectorLock on Thursday August 02, 2018 @01:12PM (#17673267)

I'm so paranoid I lockout-tagout my home breaker panel.

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