Generator and transfer switch installation

Status
Not open for further replies.
A

Acxpert

Member
Location
San Francisco, CA USA
With the pending PG&E outages looming I am looking at installing an 11kW Generac generator and transfer switch. My main panel is a 200 amp combo service entry with meter and load center.

Looking at the transfer switch literature it says to "disconnect bonding connection in panelboard". Problem is that my panel doesnt have separate neutral and grounding bars and everything is tied together. It would be a nightmare if not impossible to separate them and even it I found a way I would have to make a bunch of splices.

So, would it be acceptable to run separate ground and neutral wires from the generator and connect them to the common neutral/grounding bar in the load panel?
 
Acxpert said:
So, would it be acceptable to run separate ground and neutral wires from the generator and connect them to the common neutral/grounding bar in the load panel?
Click to expand...
Normally, the service-rated transfer switch becomes the service disconnect, and the panel becomes a sub-panel, requiring separation.

How would you intercept the line conductors between the meter and the load-center?
 
Well that is another thing I am not sure about. I was planning on disconnecting the feeders coming off the lugs below the meter and running new feeders to the transfer switch and running new feeders from the transfer switch to the load center. I tried to upload pictures and for some reason they wouldnt go....
 
Acxpert said:
Well that is another thing I am not sure about. I was planning on disconnecting the feeders coming off the lugs below the meter and running new feeders to the transfer switch and running new feeders from the transfer switch to the load center. I tried to upload pictures and for some reason they wouldnt go....
Click to expand...
That requires that the transfer switch be service-rated, and the panel becomes a sub-panel. You might be able to keep the neutral/ground bond and run all conductors through a nipple.
 
Can you please be more specific about "running all conductors through a nipple"?

Because the panel is recessed the only practical way to get wire in and out of it is to open up the wall behind the panel and to run the input and output wiring in conduit over to the transfer switch.

The Transfer switch I am looking at is service rated.
 
Without knowing the manufacturer information on the generator and transfer switch I can't give you specific information. There are one of two ways you can do a generator connection when it comes to the neutral and EGC. If the transfer switch allow switching of the neutral then you have the option of connecting the grounded and ungrounded conductors at the generator and operating the generator as an SDS. If not, then you would leave them floating in the generator. The second option is the most typical in small residential backup generator installs.

I would suggest creating a separate sub panel that will carry all generator loads. This way you can handle your load shedding since the generator can't carry the entire house. You would then install a 2 pole breaker in the house panel to feed your transfer switch and your transfer switch would feed the sub panel.

I hope this helps.
 
rlundsrud said:
Without knowing the manufacturer information on the generator and transfer switch I can't give you specific information. There are one of two ways you can do a generator connection when it comes to the neutral and EGC. If the transfer switch allow switching of the neutral then you have the option of connecting the grounded and ungrounded conductors at the generator and operating the generator as an SDS. If not, then you would leave them floating in the generator. The second option is the most typical in small residential backup generator installs.

I would suggest creating a separate sub panel that will carry all generator loads. This way you can handle your load shedding since the generator can't carry the entire house. You would then install a 2 pole breaker in the house panel to feed your transfer switch and your transfer switch would feed the sub panel.

I hope this helps.
Click to expand...

After giving it some more thought, I am thinking that maybe a manual change over might be more practical. I came across this interlock kit that is UL approved and I assume will meet code.

http://www.interlockkit.com/ProductDetails.asp?ProductCode=K-1315

Although my panel is full, I do have some space in my sub panel and can re-feed a couple other loads to create the space I will need next to the main breaker.

Thoughts?
 
Acxpert said:
After giving it some more thought, I am thinking that maybe a manual change over might be more practical. I came across this interlock kit that is UL approved and I assume will meet code.

http://www.interlockkit.com/ProductDetails.asp?ProductCode=K-1315

Although my panel is full, I do have some space in my sub panel and can re-feed a couple other loads to create the space I will need next to the main breaker.

Thoughts?
Click to expand...

If the interlock is UL listed there is no problem. But if the neutral is bonded to ground in the generator you will have to remove that bond. Especially if the generator breaker is a GFCI.
 
Status
Not open for further replies.
Top