What happens to electricity that is “grounded”?


What happens to electricity that is “grounded”?

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Quite literally, into the ground (in many cases). Basically, to avoid unwanted/dangerous build of electricity where it shouldn’t be, we give it somewhere else to build up. The earth is so massive that it can safely absorb the extra electricity.

If electricity reaches ground, it dissipates. It spreads out as much as it possibly can, basically diffusing and becoming harmless. Electricity is kind of like water – if you pour water on the ground, the water spreads out all over the ground and diffuses into the earth. Same idea.

> electricity that is “grounded”

We use the term ‘grounded’ more often to describe a device having a ground connection. Eg. “that electrical panel is grounded”

Ground is an area of low electrical potential. Sometimes, this is literally be *the earth* – as in, the device has a cable attached to it that connects it to a metal stake embedded into the earth. Other times, ‘ground’ is just to a place of relatively low electrical potential compared to the rest of the electrical circuitry – in a car, for example, the electrical components are usually grounded to the car’s chassis.

The electricity doesn’t go into the ground like a big tank of electricity.

It just completes a circuit using the ground as part of the circuit.

We connect things to the ground mainly to make sure they won’t shock you. As long as only one part of the circuit is connected, it makes no difference to the circuit since there’s no complete circuit that goes through this connection. But it does prevent static electricity build-up.

There’s also a safety purpose: if some wire breaks, for example, and it touches a grounded metal part, then it *does* complete a circuit, usually in a way that trips the circuit breaker, so you don’t get shocked by touching it later.

Usually, every metal thing you could touch is connected to the ground. That’s the purpose of the ground pin on power plugs. Also, one side of the actual circuit is connected to ground – the neutral side. Remember, this makes no difference when everything is normal.

There’s a common misconception that it just gets absorbed into the earth, but this is not the case. Electricity flows in a circuit – the current that flows out of a source of electricity always wants to return to the source.

The electricity distribution network and the wiring in every building all have a connection to ground – literally copper rods buried in the soil. When there is a fault that interrupts the normal flow of current, the ground between these copper rods literally becomes an alternate path for the current to get back to the source.

Electricity that only goes one way, like from a battery, has to go back where it came from to complete a circuit. Electricity that switches direction back and forth can go from a source into a capacitor without going back to the source, because the direction switches before the capacitor fills up, so the two electrical directions cancel each other out.

The electricity in your walls switches direction. The moist dirt under your house can act like a giant capacitor. Often for safety, electrical devices will connect a piece that’s not supposed to be electrified (like a metal shell of an appliance) to the dirt under your house, so that if a malfunction electrifies the piece, the electricity will dissipate in the dirt instead of shocking you.

The wire that connects an appliance to the dirt capacitor under your house is the ground wire. Electricity that alternates direction will cancel itself out and become harmless if you put it into the ground wire.