Thread: What if the neutral wire is not grounded at all ?

1. Regular Guest
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Sep 2015
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What if the neutral wire is not grounded at all ?

I was talking to an electrician. He told me neither nuetral nor hot wire would electrocute Had the neutral wire not been grounded ?
Is that true ? What if our systems werent grounded would the wires wouldnt electrocute at all ( under normal conditions ) ?

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2. If the neutral is truly ungrounded. The impedance of the loads determines the shock hazard.
So yes a definite risk.

3. Professional Member
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The electrician is correct....provided you truly understand what he is saying. I work in a hospital setting. I suggest you research "ungrounded isolated power systems" and "line isolation monitors".

I'll also mention that it is current, not voltage that plays a part in electrocution hazards. Current is related to resistance/impedance. Normal hand to hand resistance levels run in the range of 1k to 1M(ega ohm). Dangerous current levels are typically in the range of 50-100 milliamps. I'll let you work out the math. Keep in mind wet locations and breaks in skin change matters radically.

One must understand all the ramifications to pick the best protection. Sadly I find even PE don't always comprehend these matters. It bears mentioning that "ungrounded neutrals" aren't allowed in most circumstances.

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Thats great. I will definitely search for those topics .. Thank you so much

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The electrician is correct only in some scenarios. Depending on the topology and type of the network, if the neutral is not grounded a capacitance is created between the neutral conductor and ground.

The problem is that the voltage can become very high without restriction in this simple case.

6. My first question would be: where are you located, and what type of power distribution system is in use in your area?

7. Originally Posted by thescript
I was talking to an electrician. He told me neither nuetral nor hot wire would electrocute Had the neutral wire not been grounded ?
Is that true ? What if our systems werent grounded would the wires wouldnt electrocute at all ( under normal conditions ) ?

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The only time an ungrounded system can be considered safe is with ground detectors in place and tested regularly. If a phase grounds, the loads will all continue to work, but a person who is expecting that the system is still isolated can be electrocuted because he is essentially connecting himself across two phases when one is grounded and he touches one of the other two.

Because of this possible situation, these systems have fallen out of use over the years, and a grounded neutral system fed from a Y configuration is now the most common system.

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