Our area suffers from frequent blackouts, and many people including
myself use generators, (manually) during these periods. It would be
really helpful to know when the utility side of the circuit is once
again live so that I can put the generator away. Basically I need to
monitor the entrance cable side ahead of the main.
I thought about the simplest way which would be to wire a small NE2
neon lamp across the 240, ahead of the main, (with the appropriate
series resistor of course). The lamp would be lit all the time there
is utility supplied power and off during a blackout. The plan is to
not have to uselessly be running my generator after power unbeknown to
me is restored. The down side of this if it is really any concern
would be that this lamp, small as it as well as its associated wiring
would be would not be protected by a breaker.
The lamp is of course the simplest way, but I was wondering if there
is some sort of inductive circuit someone may know of that that would
not require that current be flowing through a conductor, basically a
circuit that would indicate the presence of voltage.
For instance I carry a little "pen" shaped device in my tool box. I
press and hold an on button and the unit chirps when brought near a
hot AC circuit. It's a great time saver when trouble shooting a job,
but can something like this be implemented as a full time monitor
circuit? It could be powered off small rechargeable batteries and
always indicate the state of the entrance cable. Thanks, Lenny