I want to do something that seems a bit more complex to myself. I want to have 4 switches in my garage that I can use to turn on the garage lights I'll be installing. (Switch on workbench, by the door, etc). Here's where I'm stumped. I want the lights to come on when ANY switch is on but only turn off if all of the switches are off. How would I accomplish this?
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Where in the world are you located?– DoxyLoverMay 1, 2021 at 6:39
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(1) Wire the switches in parallel. (2) Don't do this, it's a bad idea. (3) A standard "4-way" circuit will better serve this usage.– A. I. BreveleriMay 1, 2021 at 7:12
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1@A.I.Breveleri is it electrically a bad idea, or is it a bad idea because it will make turning the lights off extremely annoying? I'm assuming the latter.– Ryan MMay 1, 2021 at 8:26
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2I just thought of a sensible use case for this: Assume multiple garage users who cannot easily see one another, or easily know when others are using the garage. The standard multiway circuit encourages a user who assumes he is the only current user to accidentally leave the others in the dark.– A. I. BreveleriMay 1, 2021 at 9:04
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1I know you think you want that, but you don't. Consider normal 3-ways or the GE RR7 system.– Harper - Reinstate MonicaMay 1, 2021 at 19:48
1 Answer
Here is a quick sketch of some light switches connected in parallel:
If any switch is on, the lights are on. If all the switches are off, the lights are off.
Querent has not responded to requests for clarification of his purpose, but it's not impossible to imagine a use case for this circuit. Suppose the garage is used by several parties, who don't always know when others are present and using the lamps. With a "multi-way" circuit, someone leaving the garage might turn off the lights, leaving other users in the dark.
With the parallel switches, each user must turn on a switch when entering the garage, even if the lights are already on. This insure that he will not be left in the dark when he is the last one there. On leaving, each user must turn off the switch that he turned on when entering. (If the lights go off when he does this, then he knows he was the last one out, not that it matters.)
For completeness, here is what the "multi-way" circuit looks like:
with two "3-way" switches and two "4-way" switches.
Now, following the comment by Harper, a future owner of the property might want to convert to the multi-way behavior instead. Querent could facilitate the conversion by using the switches required for the multi-way, but using only the SPST functionality of each switch, and wiring them in parallel. Like this:
This saves the future owner buying new switches, but must be carefully and thoroughly documented or else it will be worse than useless.
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A similar circuit is used to control the lights in a 4 floor stairwell if timer-switches are used.– JasenMay 1, 2021 at 12:02
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1Note that the same physical wiring could also support a 3/4 way switch network, so you could easily rewire to the behavior most people would want. May 1, 2021 at 19:48
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@Harper - Reinstate Monica: Yes, with different switches. - In fact, since a "3-way" switch or a "4-way" switch can also be used as a SPST switch (by simply ignoring some of the terminals), I would wire this first as a "3/4-way" network, then convert it to a parallel switch bank by leaving the switches and just changing some connections. - The future user wouldn't even have to buy any devices to correct the circuit behavior. He would merely have to post a snarky question on Home Improvement SE about the drunken sparkmonkey who miswired his garage. May 1, 2021 at 21:18
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Ah, so pre-purchase the 3-way and 4-way switches. That's fine, though the 4-ways are $10 a pop... May 1, 2021 at 21:30
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1@Harper: I think it will be worth the extra expense now, as I am confident that "the future user who is not satisfied with parallel switches and wants to convert to multi-way switches" will be querent Nickolas Shaffer himself, after he has had a chance to try his idea in practice. May 1, 2021 at 23:41