I went to school with a very pretty girl...until you looked at the other side of her face which was pretty disfigured from exactly that...you asked about generator hook-up...I told you how to do it properly...ya know what, after seeing all the replies here on how to mickey mouse it...and how it is more desirable (or so it seems) to do it in that fashion carry on and have fun.

 

Your neutral comes from the center tap of the secondary of the transformer....look up and you will see 3 terminals...120-0-120...neutral is bonded to main ground in mains compartment of service disconnect.

 

Ahh, lets give up - he's not listening........

 

Well...it's entertaining at the very least.

 

Ok I see where you guys are missing it and its partly my fault due to bad explanation. Lets take my residence, very rural, single phase.

over the river and thru the woods first energy gives me 2 and only 2 wires. one is hot, lets say for maths sake, it is a 12kv ac signal. the other wire, what people call neutral is ALSO ground. It is connected by a wire to a metal stake at every pole. they guarantee it.

this means this wire, neutral = ground and not one microvolt different.

It feeds the primary side of the coil - which is all a transformer really is. this creates a signal that varies high to low for a total of 24kv. therefore for a 240v home I need a 100:1 stepdown. cake walk.

now mind you, this is not a dual core tranny where the utility gives you 2 180* phased hots and a neutral center tied to the center of the output side. (if they did, we'd get a proper stepdown and no voltage variance, but the utilities system is at risk in a fault scenario)

the output side, has 120, not used (you called it 0, but thats only a relative term), 120. If there was a connection to the center, its not done today standalone, or is fused and the reason is simple. the secondary side only has to have a 240v potential side to side. it DOES NOT have to be -120 to 120. It can be 0 to 240 with the center at 120volts. It can be 400 to 640 with the center at 520. This can blow stuff up in the event of a ground fault. but since the generating plant has a few square miles of copper mesh buried in the earth, their voltage signal revolves around exact zero. We should strive to do the same.

without the exact same kind of tie on the secondary side you have what one referred to as a floating 'ground'. This is bad because the sides of the transformer must always equal 240v gross potential. If you crank up a sweeper with a huge current draw, there will be a voltage drop from 'neutral' (note the quote marks which designate that it is sorta kinda a neutral) to the hot side that must be matched with a voltage INCREASE on the other side. (ever sit in an older house when someone kicks on a sweeper and the lights get brighter?)

Please assure yourself that even if I had a 0-240v condition with 120v being the 'neutral', every single damn thing in the house would STILL work (convince yourself why and you are on the way to discovering what a voltage doubler is - and the reason I was able to tickle myself with a 240v DC signal the other night on a 110v AC line, using only 2 IN4001 diodes and 2 capacitors...)

In other words, long story short - neutral is what you make it to be. I repeat, the power company does not give you a '0' neutral. Your pole does. Or should.

the transformer will always be unbalanced left to right - nothing you can do about it. one side will have less resistance than the other. nothing you can do about it. if I USED this 'neutral', which is not 0, and never will be, at the point I tied it to ground - which WILL occur somewhere, I will consume power. a small amount of power, but power nonetheless. times 60 million houses and this is about 1 power plant worth of power. We can put a $$ value on it.

So take a new installation like mine, my 'pole neutral' (meaning it comes from the pole) is tied to the pole ground. the center tap of the tranny - if equipped? - uninteresting. all I need to do is revolve my voltage swing around earth ground, like the utility does and Im happy. they are happy. everyone is happy. I could care less about any further terminals. Please note, its the tying of this neutral to ground is what solidifies my voltage swing and nothing else.

now consider another reason this is done: lets say you have a 200 amp service. as you said, your house bond is #4 wire.

It is possible to turn on everything in the house that uses one pole and not the other. In fact, 100 amps worth of stuff. wont trip the breaker, but will overwhelm the 4 wire tying neutral to ground in the even of losing one wire. you could also create a situation where there is a potential difference between the two - tripping the whole house GFI (which IIRC is now a requirement)

and as a sidebar: the vintage stereos i restore have for the most part non-polarized plugs, simply becuz when they were sold in the 70's and early 80's, a lot of houses were like that - non polarized, not even grounded.

but wait, these systems need to produce the 'rail voltages' for the amps - but as I said, they simply have to have potential, not potential around 0. 100-50 = 50, same as 50-0 and both will react with a P-N junction the same.

but wait again, they can take input signals from CD players and DVDs etc which are polarized...this is an instance where a floating ground is desired - the input op amps only need a signal difference.

but wait just a 3rd time, what if the antenna is grounded - which it will be? well each chassis has a 1Meg-Ohm chassis ground connection from the amp sides. problem solved. this really isnt all that different from what your house faces.

now lastly, since this was a thread about generators - remember what I said in an earlier post - you create a dummy plug tying neutral to ground. why? the genset has no idea what '0' is. its sorta like a secondary from a nonbonded transformer. if its a 240v gen set its 'about' -120 to 120 and the center behaves the same. by creating the dummy plug, you remove the ability for the genset to drop voltage on one side and increase on the other - IF you PROPERLY ground the genset chassis, you also tie the center voltage (neutral) to earth - 0 (all this is in the instructions for your genset btw)

and to address a question about the part I posted about - that thing was pricey over $1000 but it was fully automatic. there is no requirement that the failover has to be automatic. If I had the base switch for $200 Im still ahead.

 

I'm finished with this.

 

Im listening, I just wasnt home.

 

IF you crank up a heavy 120v load - sweeper, toaster, coffee pot, etc, and your lights get brighter, you DO have a neutral problem. And if your house is wired like you say it is, you've got BIG problems.
Not so - normal installations are supplied with a neutral from the center tap on the pole transformer secondary.
Again NOT SO. I can turn on all breakers on one leg only and will not "fry the #4ground wire". In a correctly installed system, the neutral will handle the full current, and the current in the ground wire will be very small. Note also that as you turn on breakers from the other leg, the neutral current DROPS.
Do you know how to properly ground a genset? In view of the information you have presented so far, I know you don't. One question will prove this....what type generator requires a transfer switch that switches the neutral as well as the 2 hot leads, and which type doesn't? If you don't, go back and reread post # 37 - there's a hint there.

 

You can't quit now, it's just starting to get interesting!

 

you did a pretty good impression of not reading what I wrote, or not understanding it, or using only half of sentences, or any combination of all 3.

while it is true you do not have to know how a power system works to get your license, you do in order to design one.

everything you need to know was in that post.

and to answer your question: not mine, if you READ my post(s) and follow the instructions, or as I said, RTFM for the genset, its ALSO in there.

As I pointed out, using my genset which is likely representative of what most everyone has (except many hondas), it is a floating neutral. (did you not read that part?) this would require a DPDT switch as I mentioned in a previous post is it is suitable for a non-separately derived system. since I plug 3 wires in my installation into the garage and ground the genset to the garage rebar, my bonding occurs in my panel. should I power something standalone 220 like a plasma cutter, (or tools to build a house since I *do* own a construction company and *CAN* get inspected by 'osha'), or use a temp distribution center in case of a massive power failure, that uses 110 and 220v, i have to use the dummy plug at the gen side. for the 3rd time, these instructions are in your manual.

however this is purposeful obfuscation on your part to avoid one undeniable truth: until a neutral is bonded somewhere - especially a genset - 'neutral' has no earthly idea what '0' is. neutral is relative. you have no dang way of knowing the condition of your magnets and how it excites. heck, it will excite differently on a warm day than it does on a cold day. for all you know, on your genset when you start it up, neutral can be 100 volts over earth 0. and I repeat stronger: until you understand this and WHY, do not reply. It is that fundamental.

and i theorize most of the confusion stems from not understanding what the ground in power cords are REALLY for. Grounds in power cords are human safety devices. nothing more, nothing less. they are a direct path to earth not affected by bi-directional current flow. they have zero current flow in normal operation Grounds that fail on non-GFI circuits cease to be safety devices because at that point some current is ALWAYS flowing thru them when the device is running. Once you get to the panel that fact that neutral and ground are the same to the pole is irrelevant. if I cut all 3 wires to any properly wired house service, and ran a continuity test from the moist dirt to the neutral line, i will get a signal. And I got good meters. case closed.

In the case of bonded neutral gensets, when running a load the genset frame has a voltage on it, UNLESS the frame is tied to earth directly, in that case it is a parallel circuit, contrary to strict code, but not a safety problem, keeping in mind that the ground wire in the power cable aint strictly a ground anymore.

grounds on supply lines tie neutrals or else you get the condition outlined in the 6th paragraph of this post. And there is nothing you can do about it. it just is.

now you will excuse me, blade runner is on and I like it and have missed enuf of it. As I said, do not post again until you fully understand the concepts I have outlined for you and are able to demonstrate them in a practical application. then and only then I will accept criticism.

 

You're right, I don't fully understand the concepts you outlined. Most others don't either. You have repeatedly danced around your statement that the power co. does not supply a neutral. A number of other posters beside myself have stated they do. Are we all wrong?
Me too. When someone tells me not to post, it's all over. Sayonara.....

 

Unless you or anyone else is prepared to show us one single line on any utility pole, that connects to any house in the US, that is directly connected to the power companys neutral line, then yes, you are wrong

As I stated emphatically and with no ambiguity in another post: there is no direct connection to the utility, other than mother earth.

 

I said I was done, but......one picture being worth a thousand words:
NOTE the THREE terminals on the transformer that the triplex connects to. The two outside ones are each 120 V measured to the center terminal. Across the two outer terminals is 240v. The center terminal is the NEUTRAL, and connects directly to the neutral buss bar in the service panel. There is no variation of the 120V lines in respect to neutral regardless of load. As I stated before, lose this neutral and smoke will fill the house.

 

I agree. A picture is worth a 1000 words. So I am gonna use 2000 words worth of credit, plus the ones I typed in as I notice the picture you gave, carefully does not show where any of the connections go, which is exactly the point.

These pictures are large - 3200x2700 and were taken at dusk. The image software on the camera lit them up well, but the shutter speed was too slow and I guess I shake more than I think I do, so I used the flash and 18x zoom which give the subject on a nice black background as it washes the sky.

Without further ado:



The picture above shows you exactly what I said it would and exactly what a house needs. The 'neutral' is part of the catenary. Can you have a wrapped neutral? yes, but its a waste as the 'neutral' from the pole is tied to ground - might as well make it the rust resistant steel cable. The picture labelled is self explanatory.

The weatherhead I put in 1996 when I built the garage/shop and upgraded the hosue from 100A fused panels (circa 1950's/1960's) to a 200A breakered panel.

"But this shows nothing!" you retort, that catenary can be connected ONLY to the transformer. Good point, so lets look at the next picture



This picture is not as self explanatory and since my pole is very much higher than the old one, I labelled what your are seeing. Since I zoomed in you cannot see the hot wire from the poco (7.5kv IIRC) nor the top of the tranny, but I verify there are 3 connections - 2 black coated wires for left/right and a center wire which is shown in the picture.

Now note, you see the POCO neutral/ground
To it you see attached the center wire from the transformer
You also see the pole end of the house catenary (which we have already shown supplies my neutral bus bar)
You also see the pole ground and guy wire attachment (which is just a bunch of that cable twised together
You also see another connection that runs to the second pole of the transformer primary and 'another ground' which not shown is a #4 or better coated wire to a steel rod in the earth next to the pole.

This was installed summer 07 (18 months ago-ish) by 'Penelex', aka First Energy, aka the same POCO you have, in fact, we may on the same subregion.

To sum up what I have said previously, carefully checked for spelling or missing words:

1) The 'neutral' from the POCO is tied to ground at the plant via many square miles of copper mesh buried during construction. This ties explicitly the generator neutral to '0'. Exactly zero. not .000001v above or below. Recall as I told you, an AC generator is not required by any force of nature or law of phsyics to have its neutral be at 0 volts. I said quite explicitly, there is no direct connection to the plant except for mother earth. The neutral is not isolated from the ground and the hots are isolated in a transformer.

2) Each pole with a joint, division, transformer, fuse, etc is ALSO tied to ground. This prevents any capacitive buildup in the line over distance. And it gives multiple points of reduncancy should something fall on the lines (more on that later)

3) At my pole, which is very modern and very up to code (note how unweathered my transformer is and how virginal my UT pole looks) I have a number of connections which do as I said: tie the house neutral to ground, before it gets to my house.

4) A point I tried to make that you missed was that a ground in the house simply protects humans when the current does not go back thru the neutral - nothing more. This is why we tie the equipment grounds to the busbar at the box and box only. But the ground at the pole, transformer, substation etc ties the generator output neutral to ground as it would suck if there was a voltage between POCO neutral and ground. Nothing, repeat nothing would be safe.

5) to address the OP, if a generator is the type that mine is (very likely) then the only equipment needed is the stuff I mentioned. You may spend more. It is your money. Double male ends between a gen set and a power in plug are not illegal. Mains that are not make-break-make are, when used this way.

6) I give/gave you props for mentioning words to the effect of a floating neutral. So you knew something existed. But failing to study after at least 3 times admonishing you to read up on it and understand exactly what that means and the effect it will have on your installation I have to deduct props for. That is not saying the same as me saying you are a bad person, electrician, or going to get someone killed. If you didnt understand the explanation the first time, thats ok, but you could have asked for further explanation, or links to pictures or whiteboards etc.

There is a reason all of these connections are made. AS I explained in another post, the POCO has AC current that oscillates around a 0 volt neutral. We should strive to have the exact same setup in our house.

More on what later:
I live close to Kinzua. In July 2003 a storm of historical significance came thru and caused me and pretty much everyone in 3 counties to pay attention to how our houses were wired as many were very old piggybacks. For a week I was the only one in easily 10 square miles with any lights after dark. Oddly, I had cable and phone, so I worked from home, watched tv, and was popular in the "neighborhood". However, none of the concepts I have given in this thread came from the apprenticship that got my license - most came from Mr Occhuzios Physics class in 12th grade and the rest came from my Initial major, but eventual minor in EE. To be honest, getting my license I learned nothing new about 'tricity except how to appease inspectors. Thats what I meant - its so fundamental. You probably do not have to understand it in your day job, but wouldnt it be nice to understand why you are required to do what you do? Just askin...

 

Couple last comments before I unsubscribe to this thread.
(I quoted you in full this time)
You do NOT have the same power company that I do.

The power company does supply a neutral - its the center tap on the transformer secondary. This neutral is NOT connected to the ground wire on the pole. In fact
the ONLY connection to earth ground is at one point, usually the service disconnect neutral. This is why you have to KNOW what type generator you have so you can select the appropriate transfer switch - 2 pole if your generator neutral floats, 3 pole if it's bonded to frame.
I did clip this post of yours, it was rather long and windy:
As someone who has worked in the electrical/electronics field for 40 some years, with industrial single and three phase to 460 volts and 10 KV line, as well as aircraft and mainframe computer electrical systems, I think I probably do understand .........
Bye Bye