First off, I am not an electrician and Robert you are correct about the “ground wire”, a poor term on my part.
The grounding electrode conductor and it’s eventual termination to ground better have good enough continuity to trip a breaker, otherwise what purpose does it serve? No current should ever flow through the GEC unless the neutral wire is disconnected at the utility outside the house. Hence my defining the “device grounding system” as a back-up neutral.
I was just trying to keep it straight forward as this is what the original poster was requesting. I beleive that in simple terms what I have posted is correct. A course in electrical engineering would not be helpful nor would any of the information be relavent to a home inspection.
Am I really that far off base here or are we just splitting hairs at this point?
Michael (OP), you might want to look at Basic Electrical Theory by Mike Holt and read Unit 13 (chapter 13) of that book. It explains all of this along with sketches and diagrams to better understand it. This subject is more complicated than can be condensed into a simple post or two. INACHI might even be able to provide you a copy of that book at a better price, check with HQ.
Bruce…the ITA instructor!?..Wrong!?..gasp!..bite your tongue
ok I was just kidding…the problem is me, I’m sure I missed part of that equation.
Allright now listen here y’all…people still keep talking in terms of ‘circuit’ and then Rob M inserts that little diagram of 120 coming off each side of the transformer but theres that pesky neutral in the middle. Now I was just about to retire and figure I understand about 75% and the rest I’ll just relegate to smoke and magic. But now I’m back saying where is the circuit?..since in 220 each side uses the other side (in its off phase) as ‘neutral’ so there is no circuit per se (this is still in my mind…I know that) since one side hot is only ‘circuiting’ back to the other side (seperate hot) seems more representable by a rope with a noose tied in the end…what complete circuit is there if each hot just loops back to the other hot? am I totally washed even thinking you ‘need’ a circuit…i thought you did but I’m ready and willing to be wrong
i know i sound like a broken record…you young guys probably don’t know what a ‘record’ is
The circuit is made through the load device. You only need 2 wires to make a 240V device run. No ground needed, no neutral needed. The ground is to make the metal case safe in case something shorts to it.
A/C power transmission is an awesome solution to DC methods that just does not work over long distance.
You are stuck on this ground/return thing. Think voltage and hot legs, thats what matters with 240V.
Read this entire thread again, its all there in simple terms.
great scott…I think i just got it!! let me power this down to terminology I can understand and then tell me if I’m right (essentially…no wyes and deltas) Here I go…if I pull this off I can talk intelligently with buyers.
In 120…neutral completes a circuit with power source on one end producing AC and agitating electons fourth and back each 1/60 second. Nobody needs to head to earth (though them may want to) unless some part of the setup is breached in some manner.
In 220 no neutral needed because of the AC (I think this concept may have been the real hangup for me) since there is the circuit of the two hot wires already and again the electrons are still agitated to or fro at perfectly opposing phases and still a ground is simply for errant electrons who jump the fence somehow.
and we bond the neutral and gec in the main just to make sure that all strays, however they may escape get an easy path back to source or earth, and make it so easy that they prefer that path to the one through my body.
Holy moly…can it be that easy? between batteries and illustrations and all input im thinking my light just went on. its all in the AC… say im right…even if just super basically
you guys are rock stars
(if theres a major issue with this wait till tommorrow to tell me because im practiclly having a bud moment here)
Yes, you do have it. If you want to make a visual then:
Take the sketch that Robert provided in post #25 and Save Image and then print it out 3 times, large enough to work with. You’re going to sketch in some ‘loads’ that will complete the circuit and maybe make it more understandable.
Sketch one - add a load represented by a resistor (a little zigzag line) between Black and White and another one between Red & White. Although this sketch is really of a multiwire circuit don’t let that bother or worry you. That sketch now electrically represents general 120 vac circuits you see within a home like light bulbs, fans, etc.
Sketch two - add a load (the resistor zigzag line) between Black & Red only. That shows a 240 vac load. Remember that load can be a heater, motor, pump, etc. That’s not important.
Sketch three - add a load between Black & White and another further to the right on this sketch between Black and Red. This sketch now represents a 240 vac load (like a stove top) along with a 120 vac load (like a stove clock).
Get that far and come back with observations and questions.
The purpose of a ground rod is not to facilitate the breaker tripping. The resistance of earth is too high. Ground rods are for high voltage event like a lightning strike.
The neutral to ground bond facilitiates the low impedance path back to the source to trip the breaker.
I love it…I know theres folks out there saying ‘well yeah…thats what ive been trying to tell you over and over’ Im grinning like a dumb ape…I love revelation moments
thanks to all who hung with me patiently
funny mboyett…thats just what finally did it…i printed out robs picture and sat here and drew arrows and suddenly went ‘whoa!’ and somewhere behind me fireworks bursted in midair
jim…im going to ponder your statement later, right now im busy reveling in my discovery.
now so many things that were said before make perfect sense
Robert M - Good catch. You are correct at the phasing.
Jim Port - Are you stating that a neutral conductor is not required in the wiring to an electrical appliance which uses 120v and 240 v? Are you saying that the proper wiring in these scenarios only required hot-hot-ground?
Are you also saying that there is no 110 - 220 in residential settings, and that the only voltages seen will be 120-240?
I agree and I would consider 110 and 220 similar to using slang words.
When mentioning voltage it’s best to use the standardized nomenclature. I deal mostly with 3 phase Wye systems, 208/120 and 480/277 volts. I cringe when I hear electricians say 110/220 when describing a Wye system. :shock:
