# Can i connect my Generator's neutral line with Grid's or Government neutral line?



## neeraj26jan (Apr 30, 2020)

Hi, I have a question. Right now i have connected my Generator's neutral line directly with Grid's or main line neutral and switching only between the phase of main line and phase of generator to give power supply to my house. However it does not cause any issue but still i am not sure whether is it safe or not. Can experts advice me in this regards. Thanks in advance.


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## drmerdp (Apr 10, 2018)

You have it correct. Neutral gets connected to the same bus bar that your mains neutral is connected to. If its your main panel and not a subpanel then your ground connection is likely on the same bus as well. 

Only the hot leg gets switched. 

What country and what means of feeding your house are you using? Manual transfer switch? Interlock?


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## neeraj26jan (Apr 30, 2020)

drmerdp said:


> You have it correct. Neutral gets connected to the same bus bar that your mains neutral is connected to. If its your main panel and not a subpanel then your ground connection is likely on the same bus as well.
> 
> Only the hot leg gets switched.
> 
> What country and what means of feeding your house are you using? Manual transfer switch? Interlock?


Thank your for your reply. I am from India, that is a main panel and i am using a manual transfer switch.


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## iowagold (Jan 22, 2020)

make sure you have proper grounding on the house or building!
India wiring is dicey at best in some areas!!
lol
in other areas it is just outright scary!! lol
at least from the videos that I have seen!!
hey snap a few pix of your service panel and the outside of the building where it connects to the utility!!
then we can see exactly what you have to start with!!

what are the rules in your India city for electrical work on buildings??
do you need permits? and are there rules where any electrical must be performed by an certified electrical guy?

I have thought a person who is real good with wiring could start a good biz over there and do well and make a good living at rewiring the whole country!!
getting it up to at least American grid standards..
same with most of south east asia..


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## crabjoe (Apr 20, 2020)

Sorry to take this off topic, but it is about India. Years ago, I had to take some training in pole climbing to get ready for strike duty. A picture they showed us was like the below and we were told it was from India. When I saw it, I was like WTH? How does anyone know what line goes where? All I know is that if a lot of pole look like this, those guys in India climbing poles are some brave souls, because many poles share phone and electric... And believe me on this.. even if you're only working on a phone line, it's scary when you have a transformer near your head and it's buzzing...


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## iowagold (Jan 22, 2020)

yea it is almost as bad over there as it was here in USA when dc was in some areas...
power suppliers were not using a "one transmission system"
that is why in most areas they say no to common neutral in those areas..
it is not like it is here in rural America where almost every house has its own pole transformer.. 

neutral is supposed to be grounded at the transformer to earth.. it is the point of reference...
that is why it is tricky on hose earth grounds...
if your ground rods are not ultra heavy duty as well as the connections and conductors.
then it will not stand the load!!

for me earth ground should be important! for all systems!
but in a shared environment … it is tricky at best!

you have to know the exact path of power!


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## exmar (Jun 29, 2015)

Sort of on topic, maybe. Periodically see neutral switching kits advertised. I understand they're to be used if the gen neutral is tied to ground (frame) at the unit. The intent is to assure that the neutral is only tied to ground at one place, typically in the load center. On units so equipped, they typically come with a 4 wire-240V connector. Presumably, to feed a load center, the "correct" way to do that is lift the gen frame ground and rely on the green wire from the load center. In the real world does a "double ground" really matter? Actually, not a double ground but a double grounded neutral as the only ground is the driven earth connection (usually) at the load center. I said "real world" to attempt to distinguish from the "subtleties" in the NEC. 

To further confuse this issue, I would guess that most portable gensets have frame grounded neutrals as that would be proper when used in "portable" applications, e.g. construction sites. Hopefully, someone would know to drive a ground rod. 

My question is, has anyone used a neutral switching kit in a residential portable genset application?


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## iowagold (Jan 22, 2020)

here is the thing...
it is all about reference... that is what a ground is... now in the case of single phase you really want the neutral to be the same potential as earth ground in the area where the power is consumed...
here is the rub...
some neutrals are referenced to earth ground at the utility pole where the (pig) transformer is... in some areas these are the green boxes at the end edge of your property. 
some locations make this connection at the location of the meter socket...

so what we are trying to eliminate is case ground or "skin effect" power from happening. 
this happens with induction with steel or copper or any materials that can conduct as materials in near field effect. it is parallel to the field and couples energy to the chassis or skin material of the device in question.

one thing to test your grounds is to measure ac voltage from your stove chassis to the sink drain or tap..
another is the same from a water heater chassis to the furnace and the same to sewer pipes...
any and all of these can conduct energy enough to be a problem...

at the very least it erodes the metal... and if a person gets referenced between these "hot" or different potential areas... zappo!! you get a shock or dead.

so you want the house to be at zero point... and every thing you can touch to be at zero point as well!!

the tricky part is having a large enough conductor at the reference points!! 
skinny grounds burn up!! as well as skinny neutrals!! they heat up as heat soak over time.

check your earth grounds!! wear your high voltage gloves when checking this stuff!!
and stay safe out there!!


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## exmar (Jun 29, 2015)

Iowa, nice discussion but you didn't answer the question. FYI, here in Southern Ohio, AEP is the utility, The transformer is grounded at the pole, at the end of the service wire at the weather entrance to the house another ground is driven for the load center. So everywhere in their system there are two grounds typically, 50-100 feet apart. I think someone told me they ground the "neutral" every half mile along the transmission lines. 

Thanks for the response


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## tabora (Sep 6, 2018)

exmar said:


> ...So everywhere in their system there are two grounds typically, 50-100 feet apart. I think someone told me they ground the "neutral" every half mile along the transmission lines...


In most of the US, the MGN (Multi Grounded Neutral) is tied to the ground at almost every pole:


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## iowagold (Jan 22, 2020)

exmar said:


> My question is, has anyone used a neutral switching kit in a residential portable genset application?


hey ex
no... we never change any thing on the gen sets internal wiring them selves.
if you have to "bond" or "lift" a ground it is done at the inlet or the inlet plug.. or with a bonding plug.
but we do not run in to this as we do not use the gfci outlets on the generator outlets for the connection to the generator inlet to a proper interlock connection to a house...

the honda eu 1000i, 2000i , 2200i, 3000i, 6500i and 7000is, series of gen sets do not have neutral bonding inside the generators from the factory as of 05/01/2020
that is why we only use the honda eu series. excluding the industrial and open frame gen sets from honda.

other brands.. well you will find things like this bonded ground to neutral!!
is it right??? "weelllll" lol!! depends on who sees it!! or what or how the system is reacting to this bonding..

we only run in to issues when trying to use the onboard gfci 125 volt sockets with a drop cord to a 125 volt inlet
on an interlock inlet to the breaker box.

the gfci does not like this... and same on some modern computer controlled furnace units as well.
so here is what we do!!

we only run twist locks or the parallel ports when doing a generator tie in to eliminate the gfci issue on the gen side.
and then use green as chassis ground for the gen set.
the green ground to neutral bonding is done at the main breaker panel as per local code for my area.


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## exmar (Jun 29, 2015)

Thanks Iowa, that's about where I am on this issue. I can't see any reason to use a neutral switching kit, unless, "somehow" the backup gen is located away from the house and has a separate ground provided. I guess that some manufacturers and installers don't mind selling and installing unneeded things.


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## iowagold (Jan 22, 2020)

exmar said:


> Thanks Iowa, that's about where I am on this issue. I can't see any reason to use a neutral switching kit, unless, "somehow" the backup gen is located away from the house and has a separate ground provided. I guess that some manufacturers and installers don't mind selling and installing unneeded things.


yea... there is always another gimmick some where lol.
just wire it safe.. period. and over kill is a good thing. leave at least 50% room for more power.
pricy, but safe. why take a chance of things going wrong.

now I can see if there is something heating up in a system taking a look..
but that is what the thermal camera is for.
we run in to all kinds of ground loop issues in the industrial equipment...
but that is in mfg plants that are on several acres of ground.. 
for data we use optical isolators or fiber optical lan gear for Lab view and valve controls.
as well as cctv camera systems..
in a lot of those plants due to the use of inverter motor drive units we cannot use WIFI in those plants..
just in the control or mcc rooms and the out of the plant meeting rooms..

the thing we run in to is when doing a "shut down planned repair event" 
is isolation from our gen sets to the building equipment...
the new requirement is the gfci with arc fault when using an gen set in these plants for year 2020.
it helps with shock hazard during a rain or snow event.
that is why the statement of "it is all about reference" you are only in trouble when you are referenced to ground for electric shock.
watch the videos of the guy's repairing the 200+kv powerlines via helicopter.
that will give you the shakes for sure.
a few hundred feet in the air, on a skinny wire, on a cart.
they are NUTZ for sure.. lol.
but back in the day I did tower repair when I was young..
free climb stuff.. GOOD MONEY in that!
but super high risk field of work.

we always treat every piece of equipment as a "hot chassis" when walking up to it.
always check with a proper meter with the safety gear on. high voltage gloves and hot stick meter when working on the super high voltage stuff.

oh yea when working on any electrical stuff use a high voltage rated fiberglass ladder just to be safe..
no aluminum, and try not to use wood.
safety first!
stay safe out there!


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