I actually need this set up for my workplace, but I believe you folks here will have the answer.

We need a light to come on every 30 minutes to alert staff to check something routinely. Newer staff are prone to forget or wait too long, and so a light to indicate a certain time interval has passed will do a lot of good.

Imagine a red LED that comes on every 30 minutes, a person sees it, does their routine check, presses a button which then shuts off the light resets the 30 minute timer.

I've done a lot of looking and I don't seem to see anything online that would do this, so I figure I may have to wire something myself. Everything turns things off after a set interval, but not on.

Any help would be appreciated, what I would need to do this and how I'd need to set it up. If there is anything I could purchase that will do this out-of-box that would be ideal.


  • Hello, and welcome to Home Improvement. Unfortunately, shopping questions are off-topic here. – Daniel Griscom Aug 17 '18 at 2:47

Easy peasy.

Get a common, mains-rated 30-minute rundown timer - the kind of thing you see on bathroom fans or heat lamps.

Except look for a special version of this which is either "Normally Closed", "NC" or "SPDT". You might have to hit up Galco or Grainger for this.

If you get the kind that is mechanical, it wires up like a plain old light switch. And that's exactly what you do; you wire up the switch and light exactly like a light switch circuit.

If you wire it as a "switch loop", I'll admonish you to obey NEC 2011 and provide a neutral wire. (I.e. Use /3 cable in the switch loop). That is because there are many other ways to solve this problem, and almost all of them will call for a powered device that will require neutral.

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