Joseph Gwinn wrote:

And the same is possible if the "lamp" burns out at just the wrong
time, as it is prone to do with the voltage fluctuations during
run-up. Bright-light is not as sensitive, but somewhat safer.

Use two lamps, one "lamp on" (in a green globe), the other "lamp out"
(and in a red globe)?

Never seen a "bright light" system.
Every power plant I have ever been in, that had idiot lights, had
lights that were out when in sync. All but a couple also had
synchroscopes.
jk