Well Pump Electrical Critique

[hpinson]

I'm wondering if I could get a critique on my well pump electrical setup. This was in place more or less when I got the land and I am looking to improve safety.

Main service panel, grounded, has a 50 amp breaker which feeds 4 Gauge UF 3 strand wire underground 120 feet to a outdoor weatherproof subpanel.

The subpanel is mounted outside on a post near the side of a outbuilding, and is lockable. It contains six slots, two of which have breakers in them.

One breaker is 20 amp, 120v GFCI and goes about a foot via conduit and Romex to a receptacle housed in a weatherproof box.

One breaker is 30 amp, 240v, no GFCI and 14 gauge wire is attached by a foot run to a Coyote Pump Protector, then by another foot run to a new Grundfos 240v AC pump controller, and then 120 feet underground to the well head and another 290 feet down the well (14 gauge waterproof) to a new 1/2 HP Grundfos pump. The runs above ground between the devices are all in waterproof conduit. The breaker is within site of the well head.

Several questions:

The subpanel is not grounded to a local electrode even though ground is running from the main service. Should I drive one?  My reading of code is that I should do this for a subpanel at a remote outbuilding, but it is a but gray and there are some exceptions. 

Should I replace the second underground run of 14 gauge three strand wire with something more robust?

Any other comments to improve safety?

[muldoon]

Great to hear your concerned with electrical safety!  A few things spring to mind as I read your description.

Outdoor subpanel -> conduit -> gfci outlet cabled with Romex.  Technically, romex is not suited for wet locations and outdoor conduit is considered a wet location.  You should more likely be using THHWN wiring, 12 gauge, one black, one white, one ground.  They sell this wire by the foot at most big box stores and should be really cheap to replace this.  Be sure the W is present in the wiring description, most THHN wire is also rated for THHWN.

For the second breaker, to the pump, 14 gauge wire is not suitable for 30 amp service.  (14=15amp, 12=20amp, 10=30amp) google ampacity table for industry references.  Again, since your subpanel is outside, you should use W rated wire, again by the foot is cheapest.  Of course when running single conductor wiring for 220, you'll have two hots, so be sure to get the correct amount of cable. 

For remote subpanel ground, I read and read and read on this when I did this.  I have read electricians with decades of experience arguing about this on the internet.  I did not drive a second ground rod at my remote ends, but have beefy grounds back to the main.  It was inspected by an electrician and passed.  If in doubt, call your permitting folks and see if they have a preference.

[hpinson]

Great comment, and thanks.

Is there any reason not to place an extra ground? An 8' 5/8" diameter copper rod is not expensive, nor is installation difficult. If I understand right, it won't hurt anything, or am I wrong about that?

[MountainDon]

Too many grounding rods can cause problems. I can not describe the actual reason as I do not have a firm grasp on the issue, but it has something to do with "eddy currents" or something like that. I did look into this deeply when planning our cabin electrical. There is a ground wire between the 2 panels as there should be. Then only one (or a second ground connected directly to the first ground rod) should be used. Never two ground rods connected to different parts of the same inter-grounded system. A

Also only one point in the system where there is a ground to neutral bond.