Generator wiring

   / Generator wiring #1  

tree grower

Silver Member
Joined
Dec 29, 2007
Messages
182
Location
Cuttingsville, VT
Tractor
Ford 1210, Bobcat 742B, John Deere 1050
This is a little off topic, but I bet some of you know the answer. I just bought a house built in 1979. It has a generator hook-up, but the realtor said it has never been used--not part of the issue. It was installed and wired by a reputable local electrician. Attached to the generator cable connection box is a 12-circuit load panel with a double 60 being incoming power from the main load center and a double 20 being incoming from the generator connection. The remaining 12 breakers (some are tandems) are wired to individual circuits in the main panel.

What this amounts to is circuit A being a black and white wire leaving the main panel, (but still long enough to go around the perimeter of the panel as originally wired) , but powered by a yellow (or any other color) wire from a breaker in the gen panel to the black wire, and a white wire from the gen panel to the white wire in the circuit A. With 12 out-going breakers in the gen panel there are 24 additional wires entering the main panel and wire-nutted to the existing black and white out-going wires PLUS there are circuits in the main panel that are not connected to the gen panel. The congestion of wires in the main panel is beyond anything I have ever seen.

Despite having power outages a few times per year, I have never felt it necessary to buy a generator, and I have no experience with them. I would think that a generator would just push juice into the main panel replacing what normally comes from the grid. Clearly the gen won't put out the everyday amperage, so the homeowner needs to determine what he wants to run--the water pump, freezer, refrig and furnace , but not every light and appliance in the house.

I would love to disconnect (and ultimately remove) all connections to individual circuits from the gen panel to the main panel. I am not an electrician, but I feel perfectly comfortable inside a 30 circuit 150 amp panel. Is there some good reason why I must retain this multi-colored bowl of spaghetti in my load center?
 
   / Generator wiring #2  

Rustyiron

Super Member
Joined
Mar 5, 2011
Messages
5,623
Location
Lakes Region, Maine
Tractor
M 9540 Kubota
They've had big and less complicated (and expensive) improvements in 40+ years.
One of those is available at big box orange and probably blue. It's a device that goes into your main panel and powers it and safely isolates it from the grid. You'll need to have room for an appropriate breaker and this "kit" is panel specific afaik. I have one for my backup generator if I have an issue with my main generator. 😆
Iirc it's called a generator interlock or something similar, if you're using an electrician he'll be familiar. There's a little more hardware that's involved, basically a new wire and recptical to connect the generator to the panel... properly without a cheesy cord running through an open window or door.
I'll look for a YouTube link.
 
   / Generator wiring #5  

Ken45101

Elite Member
Joined
Feb 14, 2009
Messages
3,641
Location
southern Ohio
Tractor
Kubota M5040, M9540, B21 TLB, B2710, RTV900, JD 325 Skid steer, KX-121-3 mini excavator
If I understand correctly, you really want to remove all the extra wiring and not bother with any generator connection. You are not looking for a better generator connection.

IF I understand the current wiring, you would have to disconnect the breaker on the utility side before closing the breaker on the generator side if you wanted to use a generator. IOW if both breakers were closed at the same time, the generator would backfeed the utility line. If my understanding is correct, that is dangerous and illegal. Modern code require some sort of interlock that prevents both from being closed at the same time.
 
   / Generator wiring #6  

Fuddyduddy1952

Gold Member
Joined
Aug 10, 2022
Messages
444
Tractor
john deere
I'm a do-it-yourselfer also with everything (almost). If I were faced with this it would be one of those (almost) times. I think about all the money I've saved over the years doing things but this is a case where paying an electrician I would do. I bet it wouldn't take that long to do or be that expensive. They would do it differently than I would and it would meet code plus peace of mind it's done properly and safely.
 
  • Good Post
Reactions: JJT
   / Generator wiring #7  

etpm

Platinum Member
Joined
Jun 30, 2021
Messages
767
Location
Whidbey Island, WA
Tractor
yanmar ym2310
This is a little off topic, but I bet some of you know the answer. I just bought a house built in 1979. It has a generator hook-up, but the realtor said it has never been used--not part of the issue. It was installed and wired by a reputable local electrician. Attached to the generator cable connection box is a 12-circuit load panel with a double 60 being incoming power from the main load center and a double 20 being incoming from the generator connection. The remaining 12 breakers (some are tandems) are wired to individual circuits in the main panel.

What this amounts to is circuit A being a black and white wire leaving the main panel, (but still long enough to go around the perimeter of the panel as originally wired) , but powered by a yellow (or any other color) wire from a breaker in the gen panel to the black wire, and a white wire from the gen panel to the white wire in the circuit A. With 12 out-going breakers in the gen panel there are 24 additional wires entering the main panel and wire-nutted to the existing black and white out-going wires PLUS there are circuits in the main panel that are not connected to the gen panel. The congestion of wires in the main panel is beyond anything I have ever seen.

Despite having power outages a few times per year, I have never felt it necessary to buy a generator, and I have no experience with them. I would think that a generator would just push juice into the main panel replacing what normally comes from the grid. Clearly the gen won't put out the everyday amperage, so the homeowner needs to determine what he wants to run--the water pump, freezer, refrig and furnace , but not every light and appliance in the house.

I would love to disconnect (and ultimately remove) all connections to individual circuits from the gen panel to the main panel. I am not an electrician, but I feel perfectly comfortable inside a 30 circuit 150 amp panel. Is there some good reason why I must retain this multi-colored bowl of spaghetti in my load center?
Yeah, I can think of two good reasons. One, you may one day decide you need a generator. Not for convenience, but for necessity. Two, if the current situation (like that pun?) doesn't require changing things then why take the chance of goofing things up? You can certainly undo all the wire nuts and put the wires into their respective breakers in the main panel, it won't hurt anything. But if the wires are not showing any distress from overheating wire nutted connections why change things? My generator sub panel is set up similar to yours. I wired it myself and passed inspection. Got the signed green sticker from L&I and everything. There are a lot of wires and wire nuts. But I did a neat job, it meets or exceeds code, and will not cause me any problems later on. Your installation sounds, from your description, as if it has been working for a long time trouble free. But hey, if it offends you that much then go ahead and remove the generator panel wiring.
Eric
 
   / Generator wiring #8  

orezok

Elite Member
Joined
Jan 30, 2004
Messages
3,437
Location
Mojave Desert, CA
Tractor
Kubota B7800
This is a little off topic, but I bet some of you know the answer. I just bought a house built in 1979. It has a generator hook-up, but the realtor said it has never been used--not part of the issue. It was installed and wired by a reputable local electrician. Attached to the generator cable connection box is a 12-circuit load panel with a double 60 being incoming power from the main load center and a double 20 being incoming from the generator connection. The remaining 12 breakers (some are tandems) are wired to individual circuits in the main panel.

What this amounts to is circuit A being a black and white wire leaving the main panel, (but still long enough to go around the perimeter of the panel as originally wired) , but powered by a yellow (or any other color) wire from a breaker in the gen panel to the black wire, and a white wire from the gen panel to the white wire in the circuit A. With 12 out-going breakers in the gen panel there are 24 additional wires entering the main panel and wire-nutted to the existing black and white out-going wires PLUS there are circuits in the main panel that are not connected to the gen panel. The congestion of wires in the main panel is beyond anything I have ever seen.

Despite having power outages a few times per year, I have never felt it necessary to buy a generator, and I have no experience with them. I would think that a generator would just push juice into the main panel replacing what normally comes from the grid. Clearly the gen won't put out the everyday amperage, so the homeowner needs to determine what he wants to run--the water pump, freezer, refrig and furnace , but not every light and appliance in the house.

I would love to disconnect (and ultimately remove) all connections to individual circuits from the gen panel to the main panel. I am not an electrician, but I feel perfectly comfortable inside a 30 circuit 150 amp panel. Is there some good reason why I must retain this multi-colored bowl of spaghetti in my load center?
If the 12 circuit looks something like this, what you have is an automatic transfer switch.
B1D59E69-3974-4FD1-8E77-F2B679972904.png
 
   / Generator wiring #9  

grsthegreat

Super Star Member
Joined
Jan 26, 2011
Messages
11,507
Location
north idaho
Tractor
Kioti DK45SE hst cab
If you want to remove it, all you do is disconnect all the white and black wires coming from transfer switch and reland all the house white wires back onto the neutral buss on house panel, and land the black circuit wires back onto to empty house panel breakers.
then remove the 60 amp circuit feeding the generator panel from the house panel.

Simple job.
 
   / Generator wiring #10  

rScotty

Super Member
Joined
Apr 21, 2001
Messages
6,457
Location
Rural mountains - Colorado
Tractor
Kubota M59, JD530, JD310SG. Restoring Yanmar YM165D
Houses with generators that power household circuits through the Load Center are required to have an approved Transfer Switch which positively disconnects the house from the grid when the generator is running. That is so your generator doesn't fry the guys working on the grid by "backfeeding" the power lines.

That Transfer Switch can be manual or automatic and looks like a smaller version of a load center. If manual, it will have a large manual switch on the side. If it is the automatic type it will not have a switch but will have several relays inside, along with a subcircuit to keep the battery in the generator charged. An automatic transfer switch would explain the reason for the extra wiring in the main load center.

If you have any doubts, the safe way is to disconnect the generator from your load center so it is totally independent of your household wiring. Then simply use the generator to power a couple of extension cords rather than being connected to houshold wiring.

Then when you have time to understand your system a little better you can always hook it back up to an approved transfer switch.

rScotty
 
 
Top