Some time ago, I posted here and got really great help planning my wire pull from shop (and power source) to my pump house about 350' away.

Well, I finished the pull yesterday and everything went great. 350', 4 conductors of #3 AWG THHN all done!

I can easily connect the ground and neutral at the load center and sub-panel. The sub-panel has large enough lugs on each of the neutral and ground bars. In the load center I am going to a neutral lug kit to add a large enough lug for ground and neutral.

The Question: How to terminate the the actual hot conductors?

The Problem: I have sized the wires (#3 AWG) to get < 3% voltage drop over the 350' for a 40 AMP load BUT the 40 amp breakers don't accept #3 wire.

What I would LIKE to do, but don't know if it is to code or a good idea, is to just use 60 amp breakers because the #3 works find in those.

Clearly everything in the system (mainly wire) Is rated to handle 60 amps, so IF there was ever > 60 amp load, everything would be fine and the breaker would just trip. As the load gets over 40 amps, the voltage drop will be more than 3%, but I will never be pulling > 40 amps.

Another alternative is to just splice (using an approve splice kit) to take wire down to #6, which will fit in the 40 amp breaker.

I just really don't like having to splice in a short piece of wire just to connect to breaker, but if that is the right thing, that is what I will do.

One Detail, for those that are wondering. I am not using a main breaker (or main lugs) on the sub-panel, because I have installed a generator plug and the mechanical lock out is installed on two breakers mounted across from one another (power in and generator in).

Thanks for all the help I have received in the past and any help with my current problem.

Cheers.

 

I would just just a 60A breaker. The wire is rated much higher than that.