House grounding rods???
What are they installed for??
My teacher says it's only for lightning
I say it's lightning and leakage of power and to ground the circuit cause it's not all copper these days.
What do you guys think??
Lightning is the number one reason we have rods, now a mere sibling in a family of Grounding Electrodes.
The second purpose is to provide a local connection between the neutral and ground. At the service entrance, all equipment grounding conductors are tied to the service neutral by means of the system bonding jumper. In this way, the neutral (the uninsulated wire that has the two or three insulated wires wrapped around it) is not the only way that unexpected energy can find its way to an earth ground. The transformer where the power is supplied has the center tap of its secondary tied to an earth ground, and that is also where your service neutral ends up, too.
question how do you guys drive the grounding rods into ground
i did one last week for a generator, used my jackhammer to drive it into ground it took about 3 min and head of the rod kind of stuck in jackhammers chuck
Post hole driver, then sledgehammer, then sawzall if I hit a rock.
I've always had luck with a sledge. I have a mini-sledge, and if I have to use the big sledge I'll break it out.
FYI, matt was joking about cutting them off. We all know you have to hit it a few times after you cut them off, so the inspector doesn't see a raw edge.
"Better tell the sandman to stay away, because we're gonna be workin on this one all night."
"Dude, you need more than 2 wires to a condenser to run a 2 stage heatpump."
"Just get it done son."
Rods are installed according to 250.53 G. You can drive a rod at an angle up to 45 degrees to avoid rock.
Just to clear up a term I mentioned:
The jumper for bonding at the panel is the MAIN bonding jumper. The System bonding jumper is used where to have a transformer in a store (for example) where the service is 460v, and the transformer is there to supply power to the outlets, lighting, equipment, etc, that needs 120v. In the transformer you have the SYSTEM bonding jumper, as it is a "separately derived system."
[Avatar photo from a Florida training accident. Everyone walked away.]
2 Tim 3:16-17
RSES CMS, HVAC Electrical Specialist
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