Can You Get Shocked Without Being Grounded?

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Discussion Overview

The discussion centers around the phenomenon of electric shock and the conditions under which it can occur, particularly focusing on whether a person can receive a shock without being grounded. Participants explore theoretical aspects of electrical circuits, capacitive effects, and the behavior of current in relation to the human body and AC power sources.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant suggests that if a person touches a live wire while isolated from the ground, they should not receive a shock, citing examples like birds on transmission lines. However, they note personal observations of current indicating on a tester when touching a live wire, proposing that the body may act like a capacitor.
  • Another participant references a video where a person in a "faraday cage" suit provides an alternative path for current, implying that such protective gear alters the current flow dynamics.
  • A different participant argues that circuit theory remains intact, stating that a human body can be modeled with capacitance and resistance, and that touching an AC line will always result in current flow.
  • Several participants pose hypothetical scenarios about climbing utility poles and the potential for shock, questioning where the current would flow if a person were to grab a live wire.

Areas of Agreement / Disagreement

There is no consensus on the conditions under which a shock can occur without grounding, as participants present differing views on the implications of circuit theory and the role of the human body in electrical systems.

Contextual Notes

Participants express uncertainty regarding the assumptions about grounding, the behavior of current in open circuits, and the modeling of the human body in electrical contexts. The discussion includes various hypothetical scenarios that remain unresolved.

Gruxg
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It is ussually thought that if you receive a shock touching only one cable is because you are not well isolated from ground. In theory, if you touch only one wire in one point and you are not conected to ground, you should not get a discharge (we all have seen small birds in the transmission lines). However, I have noticed that if I am standing on a plastic stool and not touching the ground anywere and I touch a live wire with one of those test lights like a screwdriver used by the electricians, it indicates current. This tester is only a light and a very high resistance between the wire and my finger, and it is indicating that the current is going into my body (with small intensity due to the high resistance of the tester). I guess my body is acting like a capacitor or something like that. It is possible to receive a painful or dangerous shock if you are not grounded, only by the capacitive effect?.

And in a more general sense, if an large object (like a human body) is conected to one of the terminals of an AC generator but the circuit is open (no return cable) and there are no other objects close to the big body that can act as "the other plate of the capacitor", can there still be a current?. If the body is sufficient large, I do not find any physical reasons to think that this would not happen. However it breaks a bit with the common asumptions of the circuit theory.
 
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skeptic2 said:

Note the guy in that video is wearing a "faraday cage" like suit. Since the guy on the wire provides an additional parallel path to the current flowing through the wire, a small percentage of current would flow through the guy if not for the "faraday cage" suit that carries that small percentage of current instead.
 
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No it doesn't break with circuit theory.
A human is usually modeled as having a capacitance relative to Earth and a resistance.
So yes, if you touch an ac line there is a always a current flowing. That's also the reason why birds never land on high voltage power lines. They may land on medium voltage lines or on the ground wire of a high voltage power line. But never on wires carrying more than a few dozen kV.
 


Just curious, let's say that someone hypothetically climbs a utility pole with no special equipment/clothing on and grabs a live wire. Will they get shocked? And if so, where is the current going through them grounding to?
 


spamctor said:
Just curious, let's say that someone hypothetically climbs a utility pole with no special equipment/clothing on and grabs a live wire. Will they get shocked? And if so, where is the current going through them grounding to?
Consider the person to be similar to an antenna connected to an 500,000 to 700,000 volt AC power source, there is current flowing through an "antenna" as the AC voltage at the powered end of the "antenna" cycles back and forth.
 
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