Ground rod installation for shed building required or not?

[LarryFine]

Now it is simpler and even less expensive to just drive two rods than to mess with proving the first one is low enough resistance.

And the trench is the perfect place to drive them.

 

[hbiss]

I know most everyone around these parts only drove one rod never measured the resistance and moved on until that change in 2011. Now it is simpler and even less expensive to just drive two rods than to mess with proving the first one is low enough resistance.

I think that's what happened here also. I don't think we (in NY) even adopted the 2011, went straight from 2008 to 2014 but I know I started using 2 rods before the 2008 but I don't know when.

The house I'm in now was built in 1955 and didn't even have a ground rod for it's original 100A service. Only bonded to the water line. So somewhere after 1955 (and whatever code we were on then, probably from the 40's) a ground rod became required.

Before my time.

-Hal

 

[mopowr steve]

If an 8 foot rod doesn't get you below frost line - it's too darn cold.

No, what I’m saying is that when the top few inches to a foot of soil freezes it heaves and pulls up on the rod. As the rest of the rod is still in damp soil and slowly gets pulled out.

Just something I have noticed after many years after even myself driving rods that I originally had maybe a couple inches above grade and now are a foot out of the ground.

 

[tom baker]

The reason that all separate buildings require a grounding electrode system is to prevent damage/fires from a lighting strike. Lighting does not care if its a 30 amp feeder or 3000 amp feeder. For a branch or multwire branch circuit, no GES is required as there is less electrical and equipment.
The GES takes care of the grounding but still need bonding, IE a 4th wire back to the source. Many in my classes and myself thought is you ran a 4 wire feeder you didn't need a GES. Nope. Still need the GES.
Orginally we would run a 3 wire feeder, GES and use the white wire for both neutral and a EGC. That hasn't been allowed since 2002

 

[kwired]

The reason that all separate buildings require a grounding electrode system is to prevent damage/fires from a lighting strike.

I don't fully agree with that. It gives a reference to ground that can give lightning a more preferred path, there is still no assurance it will prevent damage.

 

[tom baker]

I don't fully agree with that. It gives a reference to ground that can give lightning a more preferred path, there is still no assurance it will prevent damage.

My reply should of been reduce damage from fires and overvoltage, same reasons as in 250.4