During power outage, backfeeding battery bank power to main panel

[ortiesdad]

We had a power outage this evening and I began to wonder if I may be able to transfer the power from my battery bank (12-6V
@220AH batteries) to my home to run a few things like lights, fan, micro, etc. (not all at the same time of course). A little over a year ago, I had installed 5.5 KW system with micro inverters that are grid tied. I realize that these shut down during a power outage. In addition, I have eight panels that charge my battery bank in my barn, which is almost always fully charged. The subpanel in my barn supplies regular 'house power' so I have some outlets for planer and table saw but I also took a 3000 watt inverter and connected several outlets that I run small hand tools (grinder, sander, etc). So here is what I was thinking when my power is out:

1. turn off the main breaker in my house panel box
2. turn off the breaker that sends the power from the 5.5 KW system
3. turn off all breakers in my main panel box
4. make a short extension cord with two male ends and connect from the battery bank outlet out to the house power outlet
5. turn on only the breaker(s) of what I currently need such as lighting in certain areas, or microwave in my main house panel box

This would only be done during extended outage. Any thoughts or other ideas are greatly appreciated!
Dave

[Naptown]

What is the battery inverter.
It is possible to do what is called an AC coupled system which will allow the panels and micro's to work.

[ortiesdad]

What is the battery inverter.
It is possible to do what is called an AC coupled system which will allow the panels and micro's to work.

Hi Rich...the current Inverter is a POWER BRIGHT 2300 Watt continuous/4600 Watt peak model:PW2300-12

I'd be very interested to hear if I might be able to use the panels along with the micro inverters to work...Please explain.

Thanks so much!

Dave

[lkruper]

We had a power outage this evening and I began to wonder if I may be able to transfer the power from my battery bank (12-6V
@220AH batteries) to my home to run a few things like lights, fan, micro, etc. (not all at the same time of course). A little over a year ago, I had installed 5.5 KW system with micro inverters that are grid tied. I realize that these shut down during a power outage. In addition, I have eight panels that charge my battery bank in my barn, which is almost always fully charged. The subpanel in my barn supplies regular 'house power' so I have some outlets for planer and table saw but I also took a 3000 watt inverter and connected several outlets that I run small hand tools (grinder, sander, etc). So here is what I was thinking when my power is out:

1. turn off the main breaker in my house panel box
2. turn off the breaker that sends the power from the 5.5 KW system
3. turn off all breakers in my main panel box
4. make a short extension cord with two male ends and connect from the battery bank outlet out to the house power outlet
5. turn on only the breaker(s) of what I currently need such as lighting in certain areas, or microwave in my main house panel box

This would only be done during extended outage. Any thoughts or other ideas are greatly appreciated!
Dave

I believe your cord with two male ends is called a suicide cord because of the danger to the user getting electrocuted. The other danger with back-feeding, which is why it is illegal, is that if one makes a mistake the grid outside ones home is powered which is a hazard to other people.

The proper way to do this is the install a transfer switch. I just received one that will be installed soon.

[Mike90250]

If the inverter is not a pure sine wave inverter, it will likely blow out when connected to a grounded house system.

Also very dangerous, because of the cord and absence of interlocks. Get a transfer switch and do it right.

[SunEagle]

If the inverter is not a pure sine wave inverter, it will likely blow out when connected to a grounded house system.

Also very dangerous, because of the cord and absence of interlocks. Get a transfer switch and do it right.

I agree.

Unless some type of mechanical interlock can be installed that will not let you plug in that "cord" into the receptacle before your Main CB is turned off will increase the chance of someone getting hurt.

A manufactured transfer switch is the safe way to go.

[inetdog]

I agree.

Unless some type of mechanical interlock can be installed that will not let you plug in that "cord" into the receptacle before your Main CB is turned off will increase the chance of someone getting hurt.

A manufactured transfer switch is the safe way to go.

And you can either get:
1. A manual switch that transfers power to the input of the panel. This can also be done with approved breaker interlock hardware made for your panel model.
2. A manual switch that transfers the power to a critical circuits subpanel.
3. A manual transfer panel that deals with the output side of selected breakers one by one and does not involve changes to the supply side of the existing panel.