Things to know about electrical......

[mountain eagle]

I just noticed an old post in another thread with some incorrect info so I though I'd start a list........



1. Except for the first point of service after the meter, your grounds and neutrals should NOT be on the same buss. Ideally, even at the first point of service they will be kept separate as well, EXCEPT for one bonding strap that makes the neutral to ground bond.

Now we know that it's not always been the case, and there's loads of older services and subpanels out there where there is just one common neutral/ground buss. However everyone should be aware that it is less than ideal and that should you have the option to upgrade or even just clean up and separate them, you should take the opportunity to do so.

2. If you have a detached structure, from the point of service, it should have a proper ground which as noted above is kept separate from the neutral. While there are several options all of which when available should be tied together to make the grounding system, typically you will use a ground rod, likely two. Any of the following should it be available should be tied to ground, metal underground water pipe, building steel, concrete encased electrode (ufer), ground ring, and should none of those be available at a structure one of the following will be added and used, ground ring, rod and pipe electrode, plate electrode, other approved electrode. Additionally, you are usually required to have a supplemental electrode.
2a. Note that the multibranch circuit feeding a subpanel needs to be 4 wire, hot, hot, neutral, ground.

To boil it down, if a structure has metal water, ufer, or building steel they must be tied together and brought to the primary panel serving the structure. If none of those are existing (most older detached garages) you must install a ground rod. Additionally any of those may require and additional ground rod.

Example for 1 and 2 above. Service goes to the garage and under ground to the house. The neutral buss is bonded in the main disconnect panel with one strap. Otherwise all grounds and neutrals are on their own busses. The garage has no other ground, so two ground rods are installed and bonded together and to the panel. The house has water but nothing else, so an additional ground rod is installed. Water and ground rod are tied to the house main panel. That panel serves a sub panel in the basement with a 4 wire system.

3. No more than one multi-branch circuit will serve a separate building. So if you have a single 20A circuit going to an outbuilding, you can't bring others to add more circuits. The correct thing is to install a sub panel, which would likely need larger wire. As well as installing a ground.

4. Never make a junction box inaccessible. Seems obvious but I see it too often. Of course I've done it when it was for my purposes on my property........

[jbman45]

Very good post! It is one of those things never said, but should be. Grounding can be confusing and it bothered me for years and you have it right in your note. One explanation made it easier to understand from a long time electrician I know......electricity always follows the shortest route to ground! Which is why they want you to set up separate grounds for outbuildings and service, not carry the ground way back to the main panel. You want your ground as close to your major work as you can so it sees that as the shortest distance....not you!

Good post, thanks for sharing with us.