It may seem simple to most of you guys but why are we able to plug ina piece of equipment and have the voltage return on the grounded counductor but when you touch an ungrounded energized conductor to a grounded conductor the circuit will immediately short out. I can't seem to grasp what is going on electrically and theoretically???????
ungrounded to grounded?
- Thread starter justin
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Re: ungrounded to grounded?
Justin, as Dereck says it is a function of E/R
Take a 100W 120V lamp which equals 144 ohms
120/144 = .83 amps
Now if we take a resistance of say 2 ohms
120/2 = 60 amps
Let's now look at #12 solid on a 120v circuit and short it at 20 feet from the panel.
#12 has a resistance of 1.93 per k ft.
we will look at a total of 40 feet of wire.
1.93 x .040 = .0772 ohms
120/.0772 = 1554 amps
Roger
Justin, as Dereck says it is a function of E/R
Take a 100W 120V lamp which equals 144 ohms
120/144 = .83 amps
Now if we take a resistance of say 2 ohms
120/2 = 60 amps
Let's now look at #12 solid on a 120v circuit and short it at 20 feet from the panel.
#12 has a resistance of 1.93 per k ft.
we will look at a total of 40 feet of wire.
1.93 x .040 = .0772 ohms
120/.0772 = 1554 amps
Roger
Ed MacLaren
Senior Member
Re: ungrounded to grounded?
This sketch might help illustrate what the others have explained.
By the way, it would not matter if the return wire was actually grounded (connected to the earth) or not.
Ed
This sketch might help illustrate what the others have explained.
By the way, it would not matter if the return wire was actually grounded (connected to the earth) or not.
Ed
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