Does this look like a good set of parts for a grid tie system?

[reader2580]

Here are the parts I am looking at using for my grid tie system that will be a 6.1KW system. Any comments?

Qty 20 CSUN 305 watt panels
Qty 20 Solaredge P400 optimizers
Solaredge SE6000 inverter

I believe pricing on these items with shipping will be about $5,200.

I have not decided on how to do a ground mount yet plus there are a bunch of miscellaneous items I will need. I plan to go with Solaredge over SMA because the SMA inverter is more expensive and the SMA requires adding on rapid shutdown. Solaredge isn't that much more and includes rapid shutdown at each optimizer.

[Mike90250]

Why do ground mounts need Rapid Shutdown ? That's only for house mounted gear as far as I understand.

[reader2580]

I finally read section 690 of the 2014 NEC and I think I still need Rapid Shutdown because the inverter will be mounted in my garage. It seems like the NEC requires Rapid Shutdown if any PV circuit is in a building.

690.12 Rapid Shutdown of PV Systems on Buildings
PV system circuits installed on or in buildings shall include a rapid shutdown function that controls specific conductors in accordance with 690.12(1) through (5) as follows.

1. Requirements for controlled conductors shall apply only to PV system conductors of more than 1.5 m (5 ft) in length inside a building or more than 3 m (10 ft) from a PV array.

I believe Rapid Shutdown applies to me because my PV system conductors will be more than 10 feet from the array and they will be going inside my detached garage. I am still researching to verify I am correct on that. The thought process seems to be that if firefighters pull the electric meter to cut power that there should be no high voltages in any building. A PV system could still be supplying high voltages inside a building.

[inetdog]

I finally read section 690 of the 2014 NEC and I think I still need Rapid Shutdown because the inverter will be mounted in my garage. It seems like the NEC requires Rapid Shutdown if any PV circuit is in a building.

690.12 Rapid Shutdown of PV Systems on Buildings
PV system circuits installed on or in buildings shall include a rapid shutdown function that controls specific conductors in accordance with 690.12(1) through (5) as follows.

1. Requirements for controlled conductors shall apply only to PV system conductors of more than 1.5 m (5 ft) in length inside a building or more than 3 m (10 ft) from a PV array.

I believe Rapid Shutdown applies to me because my PV system conductors will be more than 10 feet from the array and they will be going inside my detached garage. I am still researching to verify I am correct on that. The thought process seems to be that if firefighters pull the electric meter to cut power that there should be no high voltages in any building. A PV system could still be supplying high voltages inside a building.

There is a little bit of room for discussion with your AHJ whether in your case the RSS needs to disconnect the DC within 10' of the array or just somewhere before it reaches the building.
The DC disconnect at the inverter is pretty clearly not going to meet the intent.

[reader2580]

Regardless of where the Rapid Shutdown is located it is still an extra expense with an SMA inverter that is not there with Solaredge. 690.12 doesn't say the Rapid Shutdown has to be within 10 feet of the array that I can tell. I believe the 10 foot thing is if your PV conductors are more than 10 feet long then you need to do Rapid Shutdown if the conductors go into or on a building.

The 2017 NEC has a change that says if you have a dedicated building that is only for PV equipment then you don't need Rapid Shutdown.

[SunEagle]

Section 690.12 of the NEC was introduced as a way to prevent the electrocution of the first responders trying to put out a fire in a building that had pv as a second power source.

There already is a way to disconnect the grid power but since solar panel keep on working and generating power there needed to be a way to disconnect that power as close to the source as possible so as not to expose anyone that may come in contact with the energized conductors.

The 10 foot rule was determined as being the best distance from the generating source to have it disconnected which allowed people to work around the energized conductors while trying to put out a building fire.

The interpretation of when the Rapid Shutdown is needed will depend on the local fire codes and AHJ which may require a procedure that is stricter then the NEC (pick a year).

IMO even if the building only has PV as it's power source then there still needs to be a way for the first responders to shut it down or reduce the hazard of electric shock to personnel.

[solarix]

If you are doing a ground mount, you just need a simple disconnecting means at the array. Just a manual disconnect like a SQ-D DU361RB mounted at the array (within 10') will be fine.
You don't need a remote shutdown unless the array is in an inaccessible location (rooftop). Your building dept may be different however - check with them.

[reader2580]

The inverter will be in my garage so I do need rapid shutdown per the 2014 NEC. Minnesota is on the 2014 NEC and will probably adopt the 2017 NEC on July 1, 2017.

I think rapid shutdown is absolutely stupid. If my detached garage is on fire the firefighters are unlikely to go into my garage to turn off the DC disconnect on my inverter. They would probably just let the garage burn because they would be afraid of electrocution from DC voltage for the array.

[SunEagle]

The inverter will be in my garage so I do need rapid shutdown per the 2014 NEC. Minnesota is on the 2014 NEC and will probably adopt the 2017 NEC on July 1, 2017.

I think rapid shutdown is absolutely stupid. If my detached garage is on fire the firefighters are unlikely to go into my garage to turn off the DC disconnect on my inverter. They would probably just let the garage burn because they would be afraid of electrocution from DC voltage for the array.

I would not try to interpret the NEC or what you think you are required to install. You still need to check with your local fire department and AHJ. They will make the final decision, not you.

[reader2580]

I would not try to interpret the NEC or what you think you are required to install. You still need to check with your local fire department and AHJ. They will make the final decision, not you.

I talked to the city and they said I need no building permit at all for solar. I do need a electrical permit. The power company requires an exterior AC disconnect.

[inetdog]

I talked to the city and they said I need no building permit at all for solar. I do need a electrical permit. The power company requires an exterior AC disconnect.

There you go! For safety and maintenance, I would definitely include some form of DC disconnect at or near the array.

[SunEagle]

I talked to the city and they said I need no building permit at all for solar. I do need a electrical permit. The power company requires an exterior AC disconnect.

Adding a disconnect switch near the array will improve the safety of the installation. It would be a smaller cost to do now then to have your pv system destroyed by the first responders because they felt unsafe by not being able to kill the DC power from the array.

Doing the minimal may save you money now only to cost you many times more in the future due to unforeseeable issues.

[reader2580]

Since my PV array will be ground mount it will be some distance from my detached garage. If anything it would make sense to put a DC disconnect on the exterior of the garage. It is pretty unlikely the PV array is going to catch on fire.

[SunEagle]

Since my PV array will be ground mount it will be some distance from my detached garage. If anything it would make sense to put a DC disconnect on the exterior of the garage. It is pretty unlikely the PV array is going to catch on fire.

Your money your choice.

[reader2580]

I talked to the fire chief and he said so long as I meet code the fire department doesn't have any specific requirements for a PV solar system.

He also said they won't pull the meter. They will turn off the main breaker if they can get to it. They call the power company to pull the meter if needed. (How long would that take if the house is on fire?)