Whole home generator help, existing system in home I bought

   / Whole home generator help, existing system in home I bought #1  

rholmes69

Bronze Member
Joined
Nov 5, 2012
Messages
50
Location
Zebulon, NC
Tractor
Mahindra 2810
Not sure when/who did the work. 30 year old home 2000sq ft, one 400sq ft addition plus attached 2 car garage and one detached 1 car garage. There is a main electrical panel on the outside of the house with breakers for the main home panel, addition panel and then the 1 car garage panel and then a couple other high amp draws (water tank, range, etc). The one car garage built in the mid 90's has a 220v outlet on the side of it that you wheel the 7k watts (12k surge) generator to and plug in. The plug runs to the electric panel in the garage and you would have to flip a 50 amp breaker. From there, I have no idea how power is distributed to the home. The neighbor says the prior owner would run the well pump, fridge, freezer and some lights when the power went off from the setup. I do not see a transfer switch/panel and have no idea on how to safely connect it and test it. I know from the limited amount of info I have read that hooking it up in an outage could send power back throught he lines and potentially kill a utility worker messing with the lines somewhere and power restored would fry the generator. Would I have to flip the breakers at the main panel on the house to off in order to "isolate" my home and then work backwards from the garage panel feeding power from it back to the main panel on the house where it is distributed to the house? I can take pics if need be.

Thanks for the help!
 
   / Whole home generator help, existing system in home I bought #2  
Can you post a picture of your main panel? It sounds like you have figured out how the previous owner ran things.
Personally, I would have the generator connect into the main panel and get an interlock such as the ones offered by Interlockkit so that it is physically impossible to have the generator breaker and the main breaker on at the same time.

Aaron Z
 
   / Whole home generator help, existing system in home I bought #3  
Not sure when/who did the work. 30 year old home 2000sq ft, one 400sq ft addition plus attached 2 car garage and one detached 1 car garage. There is a main electrical panel on the outside of the house with breakers for the main home panel, addition panel and then the 1 car garage panel and then a couple other high amp draws (water tank, range, etc). The one car garage built in the mid 90's has a 220v outlet on the side of it that you wheel the 7k watts (12k surge) generator to and plug in. The plug runs to the electric panel in the garage and you would have to flip a 50 amp breaker. From there, I have no idea how power is distributed to the home. The neighbor says the prior owner would run the well pump, fridge, freezer and some lights when the power went off from the setup. I do not see a transfer switch/panel and have no idea on how to safely connect it and test it. I know from the limited amount of info I have read that hooking it up in an outage could send power back throught he lines and potentially kill a utility worker messing with the lines somewhere and power restored would fry the generator. Would I have to flip the breakers at the main panel on the house to off in order to "isolate" my home and then work backwards from the garage panel feeding power from it back to the main panel on the house where it is distributed to the house? I can take pics if need be.

Thanks for the help!

Flip off the main breaker to disconnect from the grid first.

Flip off the breakers for everything you don't need to power.

Start the generator.

Flip the 50 amp generator breaker to on.

Enjoy your generator
 
   / Whole home generator help, existing system in home I bought #4  
Your system would definitly back feed power into the neighborhood if you don't shut off the main breaker while the generator is in use.
My suggestion would be to call an electrician about having a transfer switch installed. Not only is this safer, but think about the liability issues if some one got hurt. Also, your home owners insurance might not cover you if there was a claim that had anything to do with backfeeding power.
 
   / Whole home generator help, existing system in home I bought #5  
Can you post a picture of your main panel? It sounds like you have figured out how the previous owner ran things.
Personally, I would have the generator connect into the main panel and get an interlock such as the ones offered by Interlockkit so that it is physically impossible to have the generator breaker and the main breaker on at the same time.

Aaron Z
+1 on the interlock kit. The current setup is not fool proof and could set you up for liability. The good news is that the expensive part has already been done. If you are handy you can make your own interlock.
 
   / Whole home generator help, existing system in home I bought #6  
On every occasion so far, my generator is used only when a power line is downed. If I were to NOT remove the incoming power source first, my 25Kw PTO generator will effectively short and cause the overload protection breaker on the generator to open. No home generator can support a neighborhood with a downed power line in the circuit.
Dennis

Your system would definitly back feed power into the neighborhood if you don't shut off the main breaker while the generator is in use.
My suggestion would be to call an electrician about having a transfer switch installed. Not only is this safer, but think about the liability issues if some one got hurt. Also, your home owners insurance might not cover you if there was a claim that had anything to do with backfeeding power.
 
   / Whole home generator help, existing system in home I bought #7  
My Generac system comes with an automatic transfer switch. I'm sure you could by something similar, but you'd be looking at an electrician doing some rewiring for you. Basically, if the power goes off, my automatic transfer switch switches from utility power to back up power and the generator starts. Once utility power is restored, the switch transfers back to the grid and the generator turns itself off. You can purchase a "whole home" switch (which I should have done) which would make things much easier for you to rewire, but it's expensive. That would allow you to power anything in your house as long as you don't exceed the generators capacity and trip it's breakers.

Really, the easiest and cheapest (ie. free) way to do it is to simply trip your houses main breaker before you start your generator as has been suggested. Accidents can always happen, but the linesmen will ground out a line before working on them, and that will take your generator out anyway, but it's never a good idea to back feed the grid.
 
   / Whole home generator help, existing system in home I bought #8  
On every occasion so far, my generator is used only when a power line is downed. If I were to NOT remove the incoming power source first, my 25Kw PTO generator will effectively short and cause the overload protection breaker on the generator to open. No home generator can support a neighborhood with a downed power line in the circuit.
Dennis
Unless the line were to do down and break off on the upstream side, leaving the line from your house hanging in the air not touching anything
For those who say that they will remember to flip both breakers or the linemen will ground, will you remember to flip both breakers (both when turning on the generator and when restoring utility power) at 3am when you have been up all day clearing storm damage? Will your wife remember if she has to turn it on?
For my house, I will put in an interlock so that it is physically impossible to have the generator and utility power on at the same time. To me, its not worth the risk of zapping someone or cooking the generator because it got turned on while the utility power was on.

Aaron Z
 
   / Whole home generator help, existing system in home I bought #9  
Unless the line were to do down and break off on the upstream side, leaving the line from your house hanging in the air not touching anything
For those who say that they will remember to flip both breakers or the linemen will ground, will you remember to flip both breakers (both when turning on the generator and when restoring utility power) at 3am when you have been up all day clearing storm damage? Will your wife remember if she has to turn it on?
For my house, I will put in an interlock so that it is physically impossible to have the generator and utility power on at the same time. To me, its not worth the risk of zapping someone or cooking the generator because it got turned on while the utility power was on.

Aaron Z
Good suggestion Aaron. Thanks.
Can't happen here as I have an inline safety device! :D I have popped 2 transformers (mounted to power company poles around my neighborhood) while incorrectly? transferring from generator to grid. Don't know why and the line crew says it is impossible for me to do it from my side!! They have reviewed my installation. :confused:
They added 2 extra fuse-able links to the 7800v power grid side to prevent any damage from surges or shorts! I asked them to add one to the house side just in case but they refused.
Dennis
 
   / Whole home generator help, existing system in home I bought #10  
Good suggestion Aaron. Thanks.
Can't happen here as I have an inline safety device! :D I have popped 2 transformers (mounted to power company poles around my neighborhood) while incorrectly? transferring from generator to grid. Don't know why and the line crew says it is impossible for me to do it from my side!! They have reviewed my installation. :confused:
They added 2 extra fuse-able links to the 7800v power grid side to prevent any damage from surges or shorts! I asked them to add one to the house side just in case but they refused.
Dennis
You have a nice power company. If you did that around here, the power company would shut your power off until you had an interlock that was break before make (ie: the utility power has to be disconnected before the generator power gets turned on).

Aaron Z
 
 
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