On 12/12/2013 5:10 PM, Pete C. wrote:

Nate Nagel wrote:

On 12/12/2013 05:49 PM, Pete C. wrote:

The Daring Dufas wrote:

On 12/12/2013 3:12 PM, Pavel314 wrote:
I recently hooked my generator into the main box, with a lock-out
device of course. If the power goes out, I'll turn off the main
switch to the street manually and flip to generator power.

The problem is how to know when the street power is back on, other
than looking down the street to see if the neighbors have lights on
again. When I just ran extension cords from the generator to the
well, refrigerators, etc., during an outage, when the power started
up again various lights would light up around the house as they had
been on and were still street-connected. Now, everything is
disconnected from the street.

It would be nice if there were some sort of induction device I could
clamp on the main line coming in from the street which would light up
an LED if there were power in the line, but if there's no current
actually flowing I don't see how it would pick up the potential
voltage in the line. Is there such a thing available or will I have
to invent one?

Paul


Years ago, I installed some taps for roadies to hook up lights for the
stage in a night club. To let them know that the power was on the box
at the end of the conduit, I installed a neon pilot light for each
phase. In your case, you can get voltage sensors that can be wired to
an alarm or flashing indicator light to let you know when your main
power comes back on or just wire up a standard wall light or an exit
sign with your own panel reading "POWER". ^_^

TDD

Along those lines I installed a pair of neon indicators mounted to a
metal box cover, installed in a metal electrical box and connected to my
panel with a metal offset nipple. They are connected to the input side
of the main breaker directly, being ~18ga wire and enclosed in metal
enclosures if something fails they are self fusing and can't start
anything on fire. I use an interlock kit for the generator connection
(Square D kit in a Square D panel).


That sounds like a good idea, and probably what I would do were I trying
to do something like this myself, I just wonder if it's code compliant?

I'm not sure on that, code mostly is concerned with fire risk, and when
enclosed in all metal conduit and box the heat produced in the mS it
takes to vaporize an 18ga wire at fault currents couldn't possibly set
anything outside the enclosure on fire.


I always put an inline fuse holder on the power feeding the indicators
and install a 1 amp or smaller fuse.


Also, at what voltage do the neon indicators light up? e.g. will they
glow if there's say 10V on the line?

A quick look on Digi-Key seems to indicate a 105-125VAC rating on many
indicators. I don't see a clear indication that 105VAC is the threshold,
but I expect it's not too far below that. For more $ you could install
basic panel meters, and probably inline fuses on them, though I'd still
use the indicators as well since you can check them from a distance to
see if utility power is back.


I seem to recall 90vac as the lowest voltage that will light one of
those small neon pilot lights. ^_^

TDD