Question Re: Swamp Cooler Wiring
March 18, 2014 1:07 PM   Subscribe

My swamp cooler is not working [previously], and after taking a closer look at the wiring, I see that one of the wires is not connected. Can anyone help me understand this situation?

It looks like there are five wires going up from the switch box -- white, green, red, black, and blue. It's the blue wire that goes from the switch box to nothing, and there's a corresponding unconnected wire coming down from the cooler that looks vaguely blue (the wires are very dusty).

From the info I'm able to find, that blue wire appears to go to the water pump. My question is, if the pump wire is disconnected, wouldn't the fan motor still work? As it is, when I plug it in at all (even with the box on "off" position), the circuit breaker is tripped.
posted by Mo' Money Moe Bandy to Home & Garden (7 answers total)
So wait, last year, as we read in the linked post, you refurbished your swamp cooler and installed a new motor and a new pump, and now, after looking closer at the wiring, you suspect that the wire to the pump doesn't connect. Who did the wiring back then? On the basis of what information? That's where I'd start. One also always can look at whether the loose ends match, and whether they broke or burned off or whatever else.

In any case it wouldn't be safe at all to let some internet people diagnose what potentially is a hazard in your home.
Also, if the wires are disconnected and don't touch anything else, but the machine still trips your circuit breaker (in the "off" position!), there's apparently more going on there than that the pump isn't connected. Something does connect that shouldn't. I'd leave it alone with a vengeance, and certainly wouldn't try to plug it in any more. This is definitely work for a pro.
posted by Namlit at 1:31 PM on March 18, 2014

When the new motor and pump were installed, the guy just swapped them out and connected them at the cooler, so he didn't do any additional examination of the wiring going down into the house.

The loose wire ends don't look burned or damaged -- it looks as if the wire nut joining them fell off at some point. It's puzzling because everything did work for quite a while wired up as it is now, so the disconnected blue wire is the only thing I can think of that is different.

I did actually call an electrician who came out and looked at it today, but he just said he would rewire the whole thing and that it would cost $600-800, so I should probably just buy a new swamp cooler. I'm convinced this can be repaired without such drastic measures, and probably will get a second opinion, but in the meantime I'm just trying to understand the situation.

With the loose wire, one thing I was wondering about was whether this could be causing the breaker to trip. If neither end is touching anything, wouldn't that simply mean the pump wouldn't work when turned on?
posted by Mo' Money Moe Bandy at 1:50 PM on March 18, 2014

It's difficult to imagine a loose wire that is not touching anything (important - for example it might short out against the enclosure) causing the breaker to trip, but I'm far from an expert. Did you try replacing the circuit breaker or running it on a different circuit as was suggested before?
posted by exogenous at 2:09 PM on March 18, 2014

Seconding that if trying to turn your swamp cooler on trips a breaker and you don't know why, it's time to call an electrician instead of trusting internet strangers to diagnose the problem.

Specifically, if a breaker is tripping, there is a short or bad circuit somewhere, which could be a sign of many varied problems of varying degrees of badness. I'd hate to see someone burn their house down over saving a hundred or so on professional help.
posted by Aleyn at 2:11 PM on March 18, 2014 [1 favorite]

I did actually call an electrician who came out and looked at it today, but he just said he would rewire the whole thing and that it would cost $600-800, so I should probably just buy a new swamp cooler

If you don't have any idea how to rewire it yourself you should just hire an electrician. Your swamp cooler is a box full of water and electricity and you don't want to fuck up on this.

If you need new wiring in your wall, putting a new swamp cooler on the old wiring isn't going to do you a bit of good. You might want to talk with a different electrician.

It sounds like the wiring in your house wasn't replaced at the same time as the cooler, so I wouldn't count on the colors necessarily meaning anything on the wall wiring.

when I plug it in at all (even with the box on "off" position), the circuit breaker is tripped

Not sure if you are plugging in a standalone cooler or plugging the fan into an outlet inside the cooler. If it's a standalone cooler, it might still be under warranty.
posted by yohko at 7:19 PM on March 18, 2014

Don't forget to treat contractors like and say that you're taking bids on a small repair. This should be a sub$100 fix in my opinion unless things got very screwed up since your last repair.

When they know they are bidding against others they are much more likely to give you the straight dope and may not even charge for the estimate. Good luck!
posted by snsranch at 7:22 PM on March 18, 2014

Black, white, and green are hot, neutral, and ground and are standard for all electrical wiring. I suspect that red is the signal wire for the fan motor. It will be easier to "guesstimate" if you know and can post the model number of the swamp cooler and thermostat.

The difficulty and expense is that a tripping circuit breaker can be a bunch of different things. In-wall wiring might have gotten corroded and is causing a fault. You could have a circuit overload if the swamp cooler is still on a shared circuit. The breaker itself could be bad. All of these take time to diagnose and a swamp cooler can pull a lot of electrons so an electrician is usually going to recommend that it be put on its own circuit since that will eliminate all three of those common problems.
posted by fireoyster at 1:41 AM on March 19, 2014

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