# How to explain HOT

Discussion in 'General Electronics Chat' started by alim, Mar 10, 2009.

1. ### alim Thread Starter Senior Member

Dec 27, 2005
113
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I would be grateful , if anyone can give me an appropiate way to explain , the HOT terminal ,and WHY it is so called, My thinking is ,it is different from being called positive, as the neutral is not refered to as negative. Since it is an alternating current, why the HOT and neutral do not exchange 'roles'. I need this help to assist some newbies to AC circuits. Looking forward to your responses .TIA.alim.

2. ### alwayslearning Member

Feb 27, 2008
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There are many ways to explain this! I would suggest you google "wiring hot and neutral" the neutral is tied to ground at multiple locations. Assuming their are no faults the neutral is concidered to be ideally at ground potential. Though in reality the current through the neutral wire drops a small voltage across it due to the "ohms per meter" inherent in all conductors.

3. ### beenthere Retired Moderator

Apr 20, 2004
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A meter can establish the difference. The neutral conductor will have no voltage present, whereas the hot wire will measure 120 VAC - or 240, depending on your location in the world. Ideally, the neutral conductor should never be a shock hazard, while the hot conductor will always be dangerous to contact.

4. ### SgtWookie Expert

Jul 17, 2007
22,183
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That is not correct.
In a residential (home) AC service, neutral is tied to earth ground at only one location; between the neutral and ground busses.

Neutral is the return path for the current in the circuit.
Ground is for the safety of the human users of the various devices that are connected to the AC power.

There should never be current flowing through a ground wire; if there is, a fault exists, and must be corrected.

5. ### thatoneguy AAC Fanatic!

Feb 19, 2009
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If your body is grounded, and receive a shock/burn/death when touching a wire, that wire is HOT.

Household AC has one phase on one wire, Varying from +120 to -120 V (RMS) RELATIVE to the neutral wire. It may vary that much or more relative to the ground wire as well.

6. ### alim Thread Starter Senior Member

Dec 27, 2005
113
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Thanks for all the replies, I will google the topic as suggested by ALWAYSLEARNING.

7. ### lmartinez Active Member

Mar 8, 2009
224
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As I understand it from electricians in the field, the word "Hot" is being utilized to warned individuals of completing the circuit back to the source. What this means is that energy will flow back to the source(It is one of nature's laws). And the individual being part of the circuit will feel the "Hot (Energy, flowing through the body). It is "HOT" do not come into contact with it. As you can see, neutral, on the other hand, means no energy can flow form it. Caution!!!!!!!!! All conductors are always treated as "HOT" UNLESS OTHERWISE TESTED BY A LICENSED ELECTRICIAN or PE, engineer. I hope this can assist your question.

8. ### thingmaker3 Retired Moderator

May 16, 2005
5,072
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Physical contact with a properly wired neutral won't cause burns. Physical contact with a hot wire will indeed cause burns. ALWAYS exercise caution when dealing with electricity.

9. ### Metalfan1185 Active Member

Sep 12, 2008
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I agree with sgtwookie

neutral is the return path. and Ground is for safety. In all technicallity, the neutral is connected to ground, but not inside of the house/building.

but you may still recieve a shock from a neutral connection if there is a load on that line.

10. ### Mike33 AAC Fanatic!

Feb 4, 2005
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Yeah, several times I've come upon situations where neutral and hot have been reversed, leading to a flowing current in the neutral line!!! Had I not tested it first, it would have been "HOT". So, always follow the proper safety procedures, and never take anything for granted - some numby before you might have twisted things around...I've even had hot on a ground once, nasty situation!

11. ### alim Thread Starter Senior Member

Dec 27, 2005
113
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Thanks Imartinez, your response is of the kind I am looking for.The question is similar to 'how the flyback transformer got its name'?. The question was probably not clearly expressed. alim.

12. ### PRS Well-Known Member

Aug 24, 2008
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The power company creates a potential voltage between two legs of an alternator. One leg is planted into earth ground and so becomes harmless to animals in that it is at the same potential as anything connected to the earth -- trees, buildings, waterpipes, etc. But the other leg is sent across the countryside on power lines and the same difference of potential exists between that highline and ground as it does at the generating station.

Since we can all touch a ground and not get shocked (because it is at the same electrical potential as the earth ground), the high leg is called 'hot.'

13. ### cablguy New Member

Mar 1, 2009
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Since the field of electronics/electricity is so broad we should be careful not to make assumptions. Yes, in the typical residential US home the "neutral" is tied to ground. But for safeties sake we should also know that in most commercial/industrial situations the "neutral" is used to carry the unbalanced load and is very "HOT". IE... 208vac systems used for older three phase motors and 277vac lighting systems.
With that said and as was said earlier, treat all conductors as "HOT" until verified. And then remember that some "I-D-10-T" could still wander by and energize the line that you thought was okay to work!!

cablguy

14. ### beenthere Retired Moderator

Apr 20, 2004
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Yes, that is something to keep in mind - treat every exposed wire or terminal as if it carried a lethal voltage until proven otherwise.

15. ### italo New Member

Nov 20, 2005
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A HOT TERMINAL REFERS TO A POINT WICH IS HIGHER IN POTENTIAL TO ANOTHER POINT HAS NOTHING TO DO WITH NEUTRAL PHASE OR THE TIME OF DAY

16. ### thatoneguy AAC Fanatic!

Feb 19, 2009
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If this is true, why do you get a tingle when touching across a phone line with moist fingers?

Ground is a higher potential than -48V.

17. ### thingmaker3 Retired Moderator

May 16, 2005
5,072
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Who said anything about time of day? What are you talking about?

18. ### alim Thread Starter Senior Member

Dec 27, 2005
113
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Thanks PRS, for your response, we are getting there. alim.

19. ### PRS Well-Known Member

Aug 24, 2008
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Ok, alim, I think I see your real question. The term 'hot.' I'd guess that since hot burns, it is considered an all-encompassing term for something that burns you or shocks you.