Electrical sub-panel question

[WranglerX]

Call electrician, dig a trench from main panel to sub panel, lay in conduit and pull in wire and have electrician connect 100 amp sub panel at "shop" and at main panel.... Do it right, be safe, be happy forever...

Dale

 

[WranglerX]

Grounding is a most misunderstood element of electrical work. I always refer to the Apprentice School Textbook "Soares Book on Grounding and Bonding". Available at Amazon. That and one of the good books on DIY electrical work get me through most situations w/o digging out the NEC. There is a situation that extra grounding can create a "Ground Loop" which can be detrimental to electronic equipment especially.

Ron

YES.....

Grounding - Safety Fundamentals (1hr:13min:19sec) - YouTube

Dale

 

[CobyRupert]

Ground rod at a remote subpanel is required by Code, but IMHO it’s a big “meh”. It helps to keep static charge on metal surfaces low..big whoop.
Relying on a ground rod and earth as the path for fault current to get back to the (grounded) transformer winding isn’t a very good path. You want a low resistive path that results in high (fault) currents that trips a breaker. Low faults currents that don’t trip the breaker leaves things dangerously energized.
IMHO its more important a good ground conductor gets run to the sub-panel from the main panel (where the ground is bounded to the neutral and has a conductive path back to the opposite end of the transformer winding from where the current originated).

 

[RoyKing]

Sub panels are supposed to have ground and neutral. Ground rod connections can be the weather head, meter can, first disconnect. Most ground rod connections are very poor after a few years. the Clamp gets loose and corroded. A 10' rod seldom get you within 20 ohms, doubling to a 20' and using and exothermic weld will insure far less damage from lightening. Communications cabinets require 5 ohms or less.

 

[Tractor Seabee]

Codes and common sense don't always mesh. Having been a quasi Building/Plumbing/Electrical Inspector in conjunction with QC duties I have concluded a lot of code stuff is promulgated by manufacturers to sell their new ideas to satisfy a once in 10 million casualties. Arc fault being the latest and now it is expanding. At one time I had a shelf full of codes, standards, and reference materials almost 10' long and the stuff changes every three years. The digital world eliminated those hard copies.

Ron

 

[dragoneggs]

Code around here I believe is two rods six feet apart. Anyone that can pound a ground rod in undisturbed soil... I mean rock, has my vote. I installed a sub panel to my detached shop running 6-3 copper. Still need to add a ground rod or two.

I have three 220v circuits one being a 30amp for my welder and plasma cutter. The other two 220v are 20amp circuits that power my table saw, band saw, planer, jointer, and air compressor As it is a one man shop I am only running one of the big tools at a time and the compressor is on its own, since I never know when that will kick on. Beyond that I have two 110 20amp circuits for lighting, hand tools, a mini water heater, dust collector and air filter. Also have the original single 110v for the basic lighting and original outlets.

 

[BrokenTrack]

My ground is too rocky, and thus too close to ledge rock to drive a ground rod that way, so I do not even try. I dig a trench with my backhoe as deep as I can go, and then put the ground rod in the trench, and then back-fill.

This was a trick an electrician showed me when we were laying a lot of underground cable, and i thought it was a much better way to "drive" ground rods in the ground.

I am not sure what other electricians think of it, but I see no reason why it is not a good way to do it.

 

[BrokenTrack]

YES.....

Grounding - Safety Fundamentals (1hr:13min:19sec) - YouTube

Dale

Hey thanks guys, I will have to look into that more, because I had never heard of that phenomenon.

In my latest work, I grounded my generator engine (dedicated genset) from engine to frame, then frame to ground. But I also did that with the generator head, going from generator, to generator frame, to ground. But also the generator panel to ground. I think that would be well within reason.

 

[BrokenTrack]

Talk about Project Creep...why not just upgrade your shop to 3 phase power while you are at it! (LOL)

I actually thought about it. For $1700 I could switch over to a 3 phase power unit. Go with single phase for the house, and 3 phase for the shop...

 

[CobyRupert]

In my latest work, I grounded my generator engine (dedicated genset) from engine to frame, then frame to ground. But I also did that with the generator head, going from generator, to generator frame, to ground. But also the generator panel to ground. I think that would be well within reason.

The bigger question is did you bond the neutral and ground at the genny?
Hopefully not, unless your transfer switch also switches (& isolates) the neutral(s).