That’s arguable, all right. Since the fans actually generate heat, you have it back to front.
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Seems a little iffy. What if you can’t tell which fan was running at full speed? Ringing the circuit out is a more accurate way to tell
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Well, if one is doubtful of a 5k resistor’s ability of slowing the fan down, one can always use a 800k resistor instead. 
The warmth of the motor should be detectable, especially since he only needs to climb two floors, so less than 40 minutes total. All off a long while then two on a long while. Then one of those off. First floor either on or off. If off, is it warm? If 1st is on climb to 2nd it will be off and either cold or warm.If 1st was off,2nd will be on or off, No need to go any higher.
Easy. Old problem, solved often.
Push button #1. Pull switch panels, cross-wire the geez neutral with the plumb hot. Press button 3, for five minutes. This will enable Fan #2, at least for a while. Once Fan #2 has some time in, push button #1 again. This will famish both #2 and #3. Then meter #3, across the main bar bus, until warm. This is your first indicator. Following a brief wait (usually 2-9 minutes), refurbish the bar bus again, and retry. At this point, Fan #1 should be properly gronked. A few more tweaks will close the deal.
Finally! The home stretch. Take the hot, neutral, and ground wires, from all three. Slot all three with a Grainger coupling, flemish twice, and take a reading, Cooper’s meter. Look for a high impudence level. Spleen the plates back on, and you’re ready to climb the stairs. Last move: set all three switches into semi-state, and go up.
The fan on the left, still turning, is switch #2. Switch #3 is the little fan, and #1 will be reversed. All done! Enjoy a beer. Glad I could help.
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That telechron advert brought back memories of long, lazy days working in a nearly hidden watch repair kiosk, surrounded by 80’s era manuals and watch repair junk.
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that’s a lot of effort and he is supposed to be lazy. One switch hot, one switch off and one switch wired for continuity is simple
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Didn’t you write a fruitcake recipe?
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Yeah, spleening the grommish plates alone would take more effort than your solution, not to mention all that tedious flemishing.
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The description of the switch operation could be confusing, but I think the most obvious interpretation is that one press toggles the fan state, either off-to-on or on-to-off, nothing involving double-clicks or anything like that. Also, it seems like any of the ideas involving setting up candles or tissues in the rooms before turning on the fans would require two trips up the stairs (assuming we’re starting at the bottom). And the ideas about changing the wiring around make a lot of assumptions about how the fans are wired; for all we know, the buttons could be wireless radio transmitters and the fans could have receivers. All that being said, I can’t think of a solution to this problem. The electrician has to set each of the fans either on or off before starting up the stairs, and seemingly can’t tell anything about the history of the fans once at the top, just which ones are running and which are stopped.
And unfortunately it says the electrician can’t get any assistance, because I was all ready to make a macabre joke about putting a Korean person in each room before turning on the fans…
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It depends on the nature of the room and the temperature conditions. If, for instance, the room is air tight and windowless then yes, the heat from the fan will add to the room without anything being removed. However, if the room has any circulation with the outside world then the fan helps more rapidly redistribute and balance the temperature by recirculating the air as well as running a fluid over surfaces to help redistribute that heat as well.
if the air outside is cooler than the air inside, which it very often is when talking about an apartment with otherwise stagnant air, (from other devices like lights running to windows which trap sunlight heat,) the fan’s going to have a net cooling effect. Rooms with fans running will have lower temps than rooms that don’t in these cases.
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- All switches off.
- Mark one vane of each fan (tape, Sharpie, whatever)
- Orient all fans so marked vanes are aligned (e.g. pointing north)
- Switch “A” on and leave it on
- Switch “B” on for just a heartbeat, then off again (connected fan will move, but less than one revolution)
- Switch “C” don’t touch
Fan connected to “A”: will be spinning.
Fan connected to “B”: marked vane will no longer point north, it will have moved a fractional turn
Fan connected to “C”: marked vane will still point north
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But how do you see the results without making a second trip up the stairs?
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You can safely assume the building is wired to NEC code and the fans function like 99% of all other squirrel cage motors fans in use today.
We can probably also assume the building was not some extremely out of date or technically advanced space structure. It is an average building with average wiring.
From the switch there is at least one current carrying wire.
We can assume this only goes from the switch, strait to the fan because it says one fan operates one switch. So stop trying to add details that are not there.
The building has to be a large commercial building to be that large and the won’t be stretching romex wire up and hour worth hike of a building.
They will use raceways for the wire. All raceways have to carry a grounding conductor with a live circuit, or function as the ground wire itself.
Even without a neutral I’m the box, you can use the grounding system that is required by code and the one wire that logically has to be in the pipe connected to the fan.
You can use those two conductors to check for continuity of the circuit.
One switch on
One switch off
One switch set up for continuity
Stop trying to over complicate this problem people. It is fairly straightforward and the solution will be a simple one
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I guess the easiest response is one someone else already said,laving a fan running for an hour should produce SOME detectable change in the environment, a warm fan body, warmer or cooler room, something.
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Regardless that those are a lot of assumptions to make, I doubt this puzzle is meant to require the solver to have that much knowledge about electrical codes or electrical test equipment.
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Oh yes, missed the “climb first (& last) time bit”.
Rats. And I suppose we don’t know the pre-conditions on the switches, either.
HOWEVER, if you leave the landlord in the basement, with directions to be followed after 1 hour:
Wait, how do these switches work, anyway?
Does a single press “toggle” the switch ON|OFF?
Or are these “smart” switches where a single press is always “go ON”, and a double press is always “go OFF”.
Either way, Leave the landlord in the basement, with a watch. He has instructions to be followed at T+1:00:
- At T+1:00, press switch “A” three times at 15 second intervals between presses;
- At T+1:01, press switch “B” three times at 15 second intervals between presses
- At T+1:02, press switch “C” three times at 15 seocnd intervals between presses
Meanwhile, electrician who is now upstairs can observe state changes in the fans.
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Easy Peasy. Turn one switch on. On a second switch, take the switch out of the hot line and put it on the neutral line and turn it off (or simply make a break in this neutral line) Go upstairs.
One fan will be on. One fan will have a continuous neutral to ground and the third fan with the switch on the neutral line will have no continuity with ground.
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That’s fucking brilliant. Bravo!
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That’s my suspicion. I’m really enjoying the solutions from people with some knowledge in the field, especially the ones that involve the fans catching fire and such, but I suspect the idea was that the solution required no such specialized skills. But I mean, for all I know the person who composed it didn’t even have a specific answer, and it’s just a thought challenge!
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