Solar installation ideas for home with 2 meters

[Pinto Yates]

I have multiple electric meters on my property and am trying to ween myself from the grid one at a time.

My property originally had a mobile home and 100A meter service 325 feet from the primary power pole. In 2022 I built a new home about 250 feet away from the mobile home. For this home I installed a second 200A service but located the meter out near the primary power pole and transformer, instead of on the side of my new house. I then added 200A cut off panel at the meter and ran the 200A service underground 330’ back to the new house.

My goal is to run the new home completely off grid and I purchased a Eg4 6000ex with 25kWh of batteries and it will run everything fine since most of my heavier appliances run off propane. I’ve installed an interlock on my indoor service panel with 40A input breaker for the inverter. Tested it out and it seems to work fine With all my loads running.

My goal is to run the new home 100% off grid. Not interested in any net metering as my power Co. is terrible. I plan to leave the mobile home service on.

I have multiple questions.

1. Are there any potential issues to consider if I run underground power from the 100A mobile home to my new home to exclusively serve to power a battery charger to use to replenish my batteries in case of low solar availability?

2. Would there there be issues using this power from the other meter to grid feed the inverter? Based on where my service panel was installed in the new house, I‘d like to avoid using a critical loads panel as all my loads in the main panel can be used And I can safely cut off grid power with the interlock+cut off breaker at meter.

3. Since both meters have earth ground rods and ground bonded neutrals, is this a problem since they are coming off the same pole transformer?

4. I found that the electricians (2 different ones) left the green bonding screw in both the 200A cut off panel and a second one in my new homes interior 200A service panel. That seems wrong, so should the second bonding screw be removed since that panel is technically the sub panel?

5. There’s no earth ground at my new house since the ground rod is 330’ away at the 200A meter is this too far To effectively ground my inverter and solar equipment? Im sure multiple meters are located this close together is small lot subdivisions but I’m not sure how far my solar equipment can be from the earth ground rod for effective grounding.

Again, my goal would be to run main house with meter turned off using inverter/battery supplemented with power from solar panels (3kW now upgrading to 8kW shortly) and remotely powered battery charging. Looking for the simplest solution within the bounds of safety. Where I live there are zero inspections or code requirements but I strive to adhere to the (older) NEC standards.

thanks!

 

[Benjamin Yang]

Question: Is there a potential problem if I bring in underground power lines from my existing mobile home to a newly constructed home specifically to charge batteries in response to a lack of solar power?

Solution: This option is theoretically possible, but you need to ensure that the power cable is of sufficient capacity and that the condition of the underground cable is maintained to prevent failure. In addition, ensure that a suitable battery charge controller is installed to effectively manage the battery charging process.

Question: Is it possible to use the mobile home's meter supply to feed back to the inverter? Given the location of the service panel in the new house, he would like to avoid using a critical load panel.

Solution: This option is theoretically possible, but you need to ensure that the system is able to switch power correctly and block power from the grid when using battery power. Ensure that the appropriate switching equipment is used so that power is switched smoothly when required.

Question: As both meters have ground earth bars and grounds, is there a problem, especially as they both come from the same pole transformer?

SOLUTION: Normally, this should not be a problem as the purpose of the ground wire and ground rod is to provide a safe electrical ground. However, when connecting new power cords, ensure that they are properly grounded in accordance with the relevant electrical codes and standards.

Question: The electrician was found to have left green ground screws at both the 200A cutout panel and the 200A service panel inside the new house. He wants to know if this is correct and if the second ground screw should be removed since the panel is technically a sub-panel.

SOLUTION: If the 200A service panel inside a new home is a subpanel, make sure it is properly connected to the main panel and remove the excess ground screw according to the relevant electrical code. Proper grounding is critical to ensure electrical safety.

Question: There is no ground near the new house because the ground rod is 330 feet from the 200A meter. He wonders if this distance is too far to effectively ground the inverter and solar equipment.

Solution: In this case, make sure you use a ground wire of sufficient length and diameter to connect to the ground ground rod. Check the maximum allowable ground distance specified by the manufacturer of the inverter and solar equipment to ensure proper operation and safety of the equipment.

 

[Pinto Yates]

Thank you for the excellent response. I’ve been working on the best solutions and making some progress. Checking maximum grounding wire length is a great point. I haven’t seen that in the manual but will dig further for recommendation.

At this point I have the 6000w split phase inverter and batteries installed in garage and primary home service panel is 40’ away inside my home. I’m temporarily powering 10 circuits through my generator transfer switch but I need to,power more than 10 circuits. I installed an interlock and 40 amp breaker on the indoor panel for the inverter input and via testing, I can connect inverter directly the 40A breaker and run the entire 25 circuit panel off the inverter when connected directly to the indoor service panel, with the interlock activated.

My challenge now is to find easiest way to get 240v AC input into inverter in the garage so I can bypass inverter’s solar/battery power to the indoor panel when batteries are low or recharging batteries is needed. Not sure I can do that from indoor panel without setting up a second critical load panel indoors and pulling circuits out of main panel and that would get too messy with the service panel flush mounted into the wall. (I didn’t think there was a way to input and output power to the single indoor breaker panel, directly from the inverter since the main breaker interlock would power down both the legs in the panel).

This is why I thought it may be easier to just run 30A 240v wire 150’- 200’ from the meter at the mobile home to the inverter in garage. I’ve got enough direct burial wire left over to do it from the well installation and I’m not subject to inspections of any sort. Maybe I’m missing a more obvious and easier solution here but I haven’t found it yet.

Still not sure if there would be a grounding/Neutral issue since the power from the mobile home is grounded and neutral bonded at a different meter panel than the home meter panel is grounded and neutral bonded to. I guess all neutrals ultimately go back to the same pole transformer and the grounds are earth connected and far apart, so maybe not?

Thank you!

 

[Benjamin Yang]

Sorry, there are some issues I didn't consider

 

[MarkSolar]

NEC prohibits 2 services to same building with exceptions that don't apply to you. You can only have 2 feeders to same building if the disconnects are both in the same location. The spirit of the rule is to avoid having to know there are multiple disconnects in separate locations to make the building electrically safe. Given your physical description I don't see how you could comply with code. If you don't need to follow code, I'd put a map placard near house disconnect showing where the other disconnect is located.

 

[angelouyonzaga]

1. Running underground power from a 100A mobile home to your new home for a battery charger introduces potential issues. It's crucial to ensure that the wiring is appropriately sized to handle the current, and the installation follows safety guidelines. Additionally, consider voltage drop over the distance and use proper conduit for protection.
2. Using power from another meter to grid feed the inverter may raise safety and regulatory concerns. It's advisable to consult with a licensed electrician to ensure compliance with local electrical codes and regulations. Improper installations can pose safety risks and may not meet legal requirements.
3. Having separate meters with their own earth ground rods and ground-bonded neutrals is generally acceptable. However, consulting with an electrician is essential to confirm that your setup adheres to local electrical codes and safety standards.
4. If the 200A service panel in your new home is considered a sub-panel, the bonding screw should be removed. Sub-panels should have the neutral and ground separated to avoid parallel paths, ensuring safety and compliance with electrical codes.
5. The distance of 330' between the earth ground rod and your new house can affect grounding effectiveness. Ideally, it's recommended to have a shorter distance for more effective grounding. Consult with an electrician to explore options, such as additional grounding rods or alternative grounding solutions, to ensure the safety and effectiveness of your system.
   
   
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