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  • OT Electrical Equipment Corrosion Protection

    My new home has a deep well to supply water and the pump is located 800' down. At the well head there is a control box for the pump containing all necessary electrical equipment to run the pump (capacitor, contactors, etc) all in a nice weatherproof enclosure rated for outdoor use. The trouble is that here in the mountains we have lots of humidity at various times and moist air makes it into the enclosure and some moisture condenses inside as outside temperatures change. Making the enclosure airtight is impractical so, what I would like to do is find a spray that I can put on teh various electrical components that will prevent corrosion while note interfering with conductivity or performance of the components. The local big box store has CRC 2-26 available but before I use it I thought I would ask others for their experiences and recommendations using various corrosion control products that work on electrical equipment. I know there are LPS 2 and 3 products as well as Boeshield, and perhaps others. Any thoughts would be appreciated.
    Thanks in advance,
    Steve

  • #2
    The old stand by is Glyptol, available at most electrical suppliers.
    In some cases Dielectric grease from automotive stores works, but is messy, good for terminals etc.
    Max.

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    • #3
      What is happening is the at the box is breathing with the daily temperature cycles. In the day it heats up and vents air and in the night (when the humidity is high) if cools down and sucks air back in. The best solution is a thermostatically controlled heater in the box set for about the average daytime high temperature. That stops the breathing and keeps the air temperature above the dew point at night.
      Last edited by jlevie; 07-26-2014, 08:08 PM.

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      • #4
        www.deoxit.com is what I use on my motorcyles many and various switches and electrical connectors.

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        • #5
          There is NO SUCH THING as a box that has some form of door, and some form of inlet for wires, that doesn't let in some air. Not without more work than you want to go to, and a lot more expense. Regular conduit, poured seal fittings near the box, etc, etc.

          So you have to assume the box will let in humid air. You then need to let out the water, for which rain-tight boxes generally have weep holes.

          One factor is sun... if the box is exposed to sun, it will bake out shortly after full sunrise. That still leaves cloudy days and overnight.

          Moisture isn't harmful alone, but with dirt, or airborne contaminates, natural corrosive gases (swamp gas, etc), typically ones containing sulfur, you can have troubles. Then the heater might be needed.

          If you do use any sealant of whatever, make sure it is an electrical type, that will not contaminate contacts, damage insulation, damage other typical materials, or whatever. Most petroleum types are suspect, although some may be OK.
          Last edited by J Tiers; 07-27-2014, 12:39 AM.
          1601

          Keep eye on ball.
          Hashim Khan

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          • #6
            Originally posted by jlevie View Post
            What is happening is the at the box is breathing with the daily temperature cycles. In the day it heats up and vents air and in the night (when the humidity is high) if cools down and sucks air back in. The best solution is a thermostatically controlled heater in the box set for about the average daytime high temperature. That stops the breathing and keeps the air temperature above the dew point at night.
            We had the same problem at a cottage in NC. Solved it with several small light bulbs in series. The bulbs lasted for years since they never got really hot, but it was enough to keep the enclosure above ambient all the time.
            Any products mentioned in my posts have been endorsed by their manufacturer.

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            • #7
              Thermostat and heater is the only way to prevent moisture due to condensation. If that's not an option, slather liberally with die-electric grease.

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              • #8
                Originally posted by winchman View Post
                We had the same problem at a cottage in NC. Solved it with several small light bulbs in series. The bulbs lasted for years since they never got really hot, but it was enough to keep the enclosure above ambient all the time.
                Agreed, just find something that will output about 20W of heat and see how it does. two 100W bulbs in series should be about 25W

                Or just buy it a nightlight. It seems like any non glowing, small heater is $$$$$$$, even without a thermostat.
                Play Brutal Nature, Black Moons free to play highly realistic voxel sandbox game.

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                • #9
                  Apparently your pump is quite different from mine: my pump has a 3-wire cable that is fed into my garage, along with the plastic pipe from the pump. The control box is screwed to the wall, right next to the pressure tank. Obviously, the garage is kept above freezing. It's been working since about 1972.

                  Is there a reason your control box has to be outside?

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                  • #10
                    Originally posted by jdunmyer View Post
                    Apparently your pump is quite different from mine: my pump has a 3-wire cable that is fed into my garage, along with the plastic pipe from the pump. The control box is screwed to the wall, right next to the pressure tank. Obviously, the garage is kept above freezing. It's been working since about 1972.

                    Is there a reason your control box has to be outside?
                    My pump requires 4 wires after the control box. The well is about 200' from the house so the well drillers opted to save me some bucks on wire by running a 3 wire cable to the control box and 4 wire cable from the box 800' to the pump. The pump is a capacitor run pump, requiring 2 capacitors, one to start, one to run, hence the need for the additional wire from box to pump. Apparently there is no centrifugal switch at the pump to switch windings, probably due to the wet location. If the box had been located another 200' away the wire gauge would have need to be significantly larger and more costly.
                    At this juncture I may wish I had spent the big bucks on a larger wire and had the box located indoors, but it's far too late for that now.

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                    • #11
                      Gotcha, your pump is a bit different. Mine has the capacitor and a starting relay in the control box, with 3 wires between it and the motor. There is no centrifugal switch, just the relay, as far as I know.

                      Dunno the price difference, but I think I'd have paid it just to not have that box outside.

                      You may or may not have trouble anyway. My A/C condenser unit has a relay associated with it, outside, in the enclosure. Twice now, it's caused trouble at the beginning of the season, after sitting for several months. A slight "wiggle" to break through the oxidation and she's good to go for all Summer. Your pump will not sit for that long, so I doubt you'll have trouble at all. I wouldn't over think it.

                      If you do have trouble, it might be possible to put the entire thing in a NEMA 12 enclosure with a desiccant inside.

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                      • #12
                        Years ago I complained to a manufacturer about all the water in a raintight enclosure. He laughed and said that since no electrical conduit fittings are watertight, the term 'raintight' means 'leaks out bottom faster than it comes in!'

                        I made some keyboards that were truly watertight. After a week under water in a bucket they were absolutely dry. We put them in a greenhouse and after a month there was a teaspoon of water inside, and lots of corrosion! It turns out that the boxes breath between the strands of the wires that pass through the waterproof connector, bringing in moisture. On the same machine in the same environment was another enclosure sealed only against dripping water. It remains completely dry because it stays about 10 deg F above ambient.

                        So a little heat source will take care of the problem.

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                        • #13
                          pumpit full with silicone grease.

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                          • #14
                            A sock full of silica gel dessicant. Change/recharge twice a year.

                            doug

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