0

Since 12 gauge wire run from a 20 amp breaker is a max. of 50 feet, based on voltage drop table. I want to know if I can run 10 gauge wire from the 20 amp breaker for approx. 50 feet to a j box the 12 gauge wire from there for 25 more feet to a 2000 watt 120 volt 20 gal. electric water heater, which is all that will be on that line. Then run the same set up on another 20 amp breaker to lights, a receptacle and an exhaust fan.

Jerry Collins
  • 1
  • 1
  • Possibly related: https://diy.stackexchange.com/q/109855/95658 – Doug Deden Jun 23 '21 at 18:44
  • 3
    Where in the world did you find that 12 awg on 20 amp can only be run 50’? – Ed Beal Jun 23 '21 at 18:49
  • 1
    @EdBeal I'm not the OP, but maybe he looked at a table like this --https://www.cerrowire.com/products/resources/tables-calculators/voltage-drop-tables/ . – Doug Deden Jun 23 '21 at 18:51
  • 2
    @doug deden That question did not have a load listed. I was one of the ones answering. As a 20 amp circuit is lormally load limited to 80% or 16 amps 100’ of #12 with 16 amps at 120v is only 4.63%. 3% & 5% voltage drop max are provided as notes in the national electric code but #12 is good to 100’ there within the longest point fine print note again not code enforceable in the US. Doug be cautious on using answers that are more than a few years old code changes every 3 years and there was not an accepted answer for that question. And this was discussed in the comment after my answer. – Ed Beal Jun 23 '21 at 19:07
  • 4
    There is no 50’ limit on circuits. You may have heard a "rule of thumb" based on a wild misinterpretation of data about voltage drop. It is wrong. – Harper - Reinstate Monica Jun 23 '21 at 22:43
  • edbeal: The water heater is 2000 watts, 120 volts, therefore 16.67 amps. 80% of 20 amp breaker is 16 amps. The line would be approx. 75 feet from breaker box. Will 12 awg work in that situation all the way or do I need to do as in my question. – Jerry Collins Jun 24 '21 at 15:08

0 Answers0