20KW generic generator

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Benton

Senior Member
Location
Louisiana
Hi guys,

If you install a generator and didn't land the neutral in the generator when you go to test the generator would the lights come on?
 

hillbilly1

Senior Member
Location
North Georgia mountains
Occupation
Owner/electrical contractor
Depending on how balanced the load is, for a short while, at least until you let the smoke out.:lol: Hard to get it back in though once you let it out. (provided you have line to neutral loads, if you have no line to neutral loads, then there should be no smoke!)
 

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
Hi guys,

If you install a generator and didn't land the neutral in the generator when you go to test the generator would the lights come on?

many generators have the N and gnd connected at the generator. if you ran a ground wire out there but no n wire the N current would just run on the ground wire instead of the non-existent N wire if there is a N-G connection at the house end.
 

hillbilly1

Senior Member
Location
North Georgia mountains
Occupation
Owner/electrical contractor
many generators have the N and gnd connected at the generator. if you ran a ground wire out there but no n wire the N current would just run on the ground wire instead of the non-existent N wire if there is a N-G connection at the house end.

True, but most of the residential generators have "Floating" neutrals.:)
 

ceb58

Senior Member
Location
Raeford, NC
They should come on if the neutral is not switched in the transfer switch. The utility line neutral, the gen. line neutral and the load neutral would all be bonded together in the ATS.
 

hillbilly1

Senior Member
Location
North Georgia mountains
Occupation
Owner/electrical contractor
They should come on if the neutral is not switched in the transfer switch. The utility line neutral, the gen. line neutral and the load neutral would all be bonded together in the ATS.

But the OP is saying the neutral is not connected at the generator. If the neutral is floating, like on most residential sets, the return path would be the hot legs only, creating an open neutral condition. If the neutral was connected, then the common tie in the transfer switch would ground it through the service neutral as you stated.
 

kwired

Electron manager
Location
NE Nebraska
The neutral is connected, it is the equipment grounding conductor that is floating on most of them.
??????

You probably have the right idea but your wording gave me the wrong impression.

The neutral has to be connected to the mid point of the generator winding or you will have "open neutral" problems. When you say the neutral is "floating" that is what came to my mind.

I see it as there is typically no neutral to equipment grounding conductor bond - leaving the equipment grounding conductor the "floating conductor" These generators are "ungrounded systems" even connecting a grounding electrode to the lug on the frame still leaves the system ungrounded, all it does is ground the equipment grounding conductor.

When properly connected to a premises wiring system, the generator neutral and equipment ground are separately brought to the system bonding jumper of the premises system and that is where the bond takes place, not in the generator.
 

hillbilly1

Senior Member
Location
North Georgia mountains
Occupation
Owner/electrical contractor
You probably have the right idea but your wording gave me the wrong impression.

The neutral has to be connected to the mid point of the generator winding or you will have "open neutral" problems. When you say the neutral is "floating" that is what came to my mind.

I see it as there is typically no neutral to equipment grounding conductor bond - leaving the equipment grounding conductor the "floating conductor" These generators are "ungrounded systems" even connecting a grounding electrode to the lug on the frame still leaves the system ungrounded, all it does is ground the equipment grounding conductor.

When properly connected to a premises wiring system, the generator neutral and equipment ground are separately brought to the system bonding jumper of the premises system and that is where the bond takes place, not in the generator.

Correct, the neutral is "Floating" until it is connected to the neutral bar in the transfer switch, where it is bonded through the utility neutral. If the transfer switch switches the neutral, then the neutral ground bond would be installed at the generator (not common at all in residential)
 

kwired

Electron manager
Location
NE Nebraska
Correct, the neutral is "Floating" until it is connected to the neutral bar in the transfer switch, where it is bonded through the utility neutral. If the transfer switch switches the neutral, then the neutral ground bond would be installed at the generator (not common at all in residential)

I think we are on same page.

The neutral is floating from ground, but I initially deciphered what you said to mean the neutral to be floating from the generator winding, that would be highly undesired.
 

hillbilly1

Senior Member
Location
North Georgia mountains
Occupation
Owner/electrical contractor
I think we are on same page.

The neutral is floating from ground, but I initially deciphered what you said to mean the neutral to be floating from the generator winding, that would be highly undesired.

Yeah, that would not be good, especially for the manufacture! Sitting here waiting for an inspector right now on a 100 kw unit. You gotta love sometime between 8:00 am and 4:30 pm!
 

ceb58

Senior Member
Location
Raeford, NC
But the OP is saying the neutral is not connected at the generator. If the neutral is floating, like on most residential sets, the return path would be the hot legs only, creating an open neutral condition. If the neutral was connected, then the common tie in the transfer switch would ground it through the service neutral as you stated.

We are on the same page. What I am saying is if the utility, gen. and load neutral were bonded together and isolated ( my term for floating) the lights would work even though the neutral was not connected in the gen.
 

hillbilly1

Senior Member
Location
North Georgia mountains
Occupation
Owner/electrical contractor
We are on the same page. What I am saying is if the utility, gen. and load neutral were bonded together and isolated ( my term for floating) the lights would work even though the neutral was not connected in the gen.

But if the neutral is NOT connected at the generator, it will be an open neutral condition because the only return path is the two hots. Doesn't matter if the other end of the neutral is terminated to the neutral bar in the transfer switch if it's not connected at the generator. Believe me, I know, one of my guys installed one at a house where he taped up the wires to push them through the wall, he failed to untape them all the way and missed terminating the neutral from the generator. He terminated the hots and the ground. He fried the customers wireless phones, tv, and other electronics.
 

Ridgewiz

New member
If no Neutral is connected at Generac Gen?

If no Neutral is connected at Generac Gen?

I can tell you from experience, if you do not connect a neutral to the generac gen, your lights will come on but they will be very dim & you gen will be putting out 440V AC but it will be unbalanced (maybe 120vAC on one leg and 320vAC on the other leg). The ground from the TS (transfer switch) was connected at the gen. As stated already, the Generac gen has a floating neutral. The ground & neutral bar at the rear of the gen are kinda hard to see due to the lid of the gen. But they are seperated by a small piece of plastic. No, the magic smoke didn't come out of the lights. As far as I know there was no damage to the gen or the load. After installing a neutral from the TS to the neutral bar in the gen, all was well. Ohhhh how foolish I felt after discovering the error of my way. :blink:
 

kwired

Electron manager
Location
NE Nebraska
I can tell you from experience, if you do not connect a neutral to the generac gen, your lights will come on but they will be very dim & you gen will be putting out 440V AC but it will be unbalanced (maybe 120vAC on one leg and 320vAC on the other leg). The ground from the TS (transfer switch) was connected at the gen. As stated already, the Generac gen has a floating neutral. The ground & neutral bar at the rear of the gen are kinda hard to see due to the lid of the gen. But they are seperated by a small piece of plastic. No, the magic smoke didn't come out of the lights. As far as I know there was no damage to the gen or the load. After installing a neutral from the TS to the neutral bar in the gen, all was well. Ohhhh how foolish I felt after discovering the error of my way. :blink:

If we are talking a 120/240 output and the neutral is left floating or "open" you will have unbalanced voltage that will vary depending on connected load, but it will never be higher than the applied 240 volts.
 
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