Overhead neutral not insulated

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The electron man said:
Now I'm confused
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He's referring to the fact that current is what causes voltage drop.

Conductors attempt to keep their load ends at the same potential as their source ends.

Also, current, as the result of voltage between points given a conductive pathway, is what causes damage.
 
Ok try this: consider a pole transformer serving a house. At the secondary of the transformer, the center tap, which is just the midpoint of the secondary winding, is grounded. Thus the neutral conductor is at the same potential as the Earth AT THAT POINT. If there is no current flowing on the system, then the neutral conductor and the Earth will be at the same potential everywhere, the exact same. Now consider the real life case where current is flowing. Think of ohm's law: Whenever you have current flowing there is a voltage drop. So as you move further away from the grounding point yes the potential will deviate from Earth. But if you just run some numbers for typical wire length resistance and amps flowing, you will probably only get a few volts of difference between neutral and ground.
 
There is insulated triplex available where the nuetral is covered. The coast utility I mostly work with now does this. It's not to protect against shock but rather to gain life expectancy of the wire.

Nuetral is bare in SE cables used as service cables also. The issues that you get from air corrosion is far less than in ground corrosion. Also the GEC is often bare and tied to this same system. I prefer it being bare to make it obvious what it's purpose is and when hitting an in ground electrode it adds surface area to the GEC system and the ground. This is entirely separate though.

Last reason is utility's aren't subject to NEC we can use triplex and quadruplex overhead according to the NEC but if we weren't utilities would still be allowed. They have bare wires on insulators for all their large primary wires also that use ceramic and air as insulators.
 
The electron man said:
Doesn't an uninsulated neutral pose a safety risk ??
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The electron man said:
Or since its already grounded there is really no risk ?
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Yes, and No. As others have said the neutral being grounded at both the utility transformer and at the premises it is put to the same potential to earth limiting the risk.
NEV resulting from voltage drop does increase the touch potential but usually at a level that it is not usually considered a safety concern. But there are conditions that this increase in touch potential can be hazardous, such as an open neutral or ground, or in a swimming pool.
An open neutral or ground, depending on location of the opening, can put you, if in contact, in a position of an alternate path for the imbalance and VD to travel. And an increased Risk when making contact.
In a swimming pool the touch potential can be hazardous at a much lower level than in other environments due to the potential for shock drowning, where the touch potential is not enough to cause electrocution under other conditions but enough to cause a disruption of muscle control and subsequent drowning, in a pool or other body of water. This is why proper equal-potential bonding so critical in a swimming pool environment to put anything within reach while in the water to the same potential to limit the risk.

So really anything that results in a difference of potential can put a person at risk if you become an alternate path.
 
In general the only voltage on the neutral as measured to earth is that caused by the voltage drop on the neutral. That is typically a low enough voltage to not be a hazard.
However a poor connection or an open neutral will result in line to neutral voltage between the neutral and the earth and that is hazard. In addion where the utility transformer is connected line to neutral on the primary side, the voltage drop on the primary neutral will also be on the secondary neutral as they are connected together at the transformer.
 
Fred B said:
Yes, and No. As others have said the neutral being grounded at both the utility transformer and at the premises it is put to the same potential to earth limiting the risk.
NEV resulting from voltage drop does increase the touch potential but usually at a level that it is not usually considered a safety concern. But there are conditions that this increase in touch potential can be hazardous, such as an open neutral or ground, or in a swimming pool.
An open neutral or ground, depending on location of the opening, can put you, if in contact, in a position of an alternate path for the imbalance and VD to travel. And an increased Risk when making contact.
In a swimming pool the touch potential can be hazardous at a much lower level than in other environments due to the potential for shock drowning, where the touch potential is not enough to cause electrocution under other conditions but enough to cause a disruption of muscle control and subsequent drowning, in a pool or other body of water. This is why proper equal-potential bonding so critical in a swimming pool environment to put anything within reach while in the water to the same potential to limit the risk.

So really anything that results in a difference of potential can put a person at risk if you become an alternate path.
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I watch a mike Holt video explaining Nev neutral to earth voltage and how the utility has a multi point grounding on the service neutral now it all make a lot more sense thanks
 
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