I was helping a friend change his deep water well pump which is rated at 220 volts AC,3/4 H.P. Most of these I have seen are wired with three yellow wires that run from the pump to the pump switch on the water tank that are stranded. His was wired with three yellow stranded wires that were rated for the same voltage from the pump up to the top of the casing, where they installed the pump switch and used a coiled water tubing to connect to the pit-less adaptor to work the switch. From the switch they ran a 220 line underground, grey color, solid, three wire to the fuse box inside the house.

Which wire is better for this use? Solid or Stranded?

  • The pressure switch is outside in the well? What is the climate? I would definitely be worried about it freezing..
    – gregmac
    Jun 26, 2012 at 4:33
  • Yes gregmac;Pressure switch is on a four foot PVC pipe,that is then lowered into well casing,i think that keeps it from freezing.And you can pull it up to replace it.Being it,s attached to a 12 foot coil plastic tubing down to the pitless adaptor.I,v never seen this done before,but being they buried the water holding tank underground mite explain it? This is in N.E.Pennsylvania.
    – PAUL
    Jun 27, 2012 at 14:21
  • Water holding tank?? This sounds like a dug well, or a drilled well in a well pit. You don't want surface water to infiltrate drilled wells, which is why we no longer use well pits. The WellAware site has a lot of good info on this stuff -- unrelated to the original question, but you may want to check it out. Floats in dug wells are rare, in my experience, and if it's not a dug well it's a warning flag something was done wrong.
    – gregmac
    Jun 27, 2012 at 16:12

1 Answer 1


The biggest difference in solid and stranded is the flexibility of stranded. It is easier to pull and bend. One does not handle more amperage or voltage than the other, unless you get into fine stranded cable like a battery or welder, which are not used as building wire.

  • 2
    +1 flexibility is the big plus for stranded. If it is not needed, solid is chosen because it is typically less expensive.
    – pilotcam
    Jun 26, 2012 at 2:32
  • 2
    I have worked on many wells, and I can picture two where solid wire was used and we were replacing it: in one case, it was brittle and had snapped, and in the other it had rubbed against the exterior of the well and broken the line. In at least the second case, the wire may have worked if it was secured to the pipe (taped every few feet): every time the pump starts up, it spins the whole thing probably 90 degrees, so if you leave the wire hanging there over time it'll damage it. Stranded wire is probably less affected by this, but still can have the same problems.
    – gregmac
    Jun 26, 2012 at 4:39
  • In my opinion, as long as you are using submersible pump wire and have it secured properly, you're okay. Most common is stranded submersible pump wire, but they also make stuff that looks the same but is solid (it's just less flexible). Also, any connections in or around the well should be done with heat-shrink connections, I've seen wire nuts used at the top of the well and that's just a safety hazard if they fall apart or get wet.
    – gregmac
    Jun 26, 2012 at 15:43
  • 1
    Actually we suggest either a resin kit 3M 82A Series for underwater or cold shrink for moisture tight seals. A lot of times the insulation on heat shrink is too thin.
    – lqlarry
    Jun 27, 2012 at 2:05
  • Thanks lqlarry;Thats what i was wondering! Which one of these wires would carry the amperage or voltage better.
    – PAUL
    Jun 27, 2012 at 14:27

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