Clearance between front of electrial panel and inverter

[ArCal]

I have an existing situation where a 200 amp electrical panel is located in an alcove with 3'4" in front. The owner just installed a PV system and placed the inverter on the wall in front of the panel. Now there is only 30" between the front of the panel and the inverter. He is going to have to remove the inverter to get the 36" required. This bought up a question. If the inverter was installed in front of the panel, what would be the required distance from it to the inverter? Table 110.26(A)(1) notes 3 different conditions which determine the space in front of a panel, would the inverter create condition 2 or 3? I would appreciate any comments.

Thank you.

 

[c_picard]

What does the AHJ say? I'd go with 4 ft(151-600V to ground on a grounded system, which that is) to be safe, but I don't think it's likely that both pieces of equipment would need to be serviced with their covers off at the same time. Condition 3.

Hard to tell from the pic, but it looks like if you stack the two Sunny Boys on top of each other your clearance issues go away. Careful moving that inverter, I don't see a DC disconnect.

 

[cowboyjwc]

What does the AHJ say? I'd go with 4 ft(151-600V to ground on a grounded system, which that is) to be safe, but I don't think it's likely that both pieces of equipment would need to be serviced with their covers off at the same time. Condition 3.

Hard to tell from the pic, but it looks like if you stack the two Sunny Boys on top of each other your clearance issues go away. Careful moving that inverter, I don't see a DC disconnect.

The DC disconnect is on the bottom of the inverter.

I would think that as long as you had three feet clear that it wouldn't be an issue.

 

[c_picard]

That disco won't help...

That disco won't help...

I saw the integrated disconnect, but if you're moving the whole inverter, it doesn't help if there's nothing on the array side, DC conductors are live during daylight hours. That's why I said be careful. Better yet, hop on the roof and break the circuit at the modules(not under load). Or wait till dark!

 

[c_picard]

A panel should definitely be considered grounded, and a typical inverter operates at more than 150V to ground, so how in this situation would 3ft be enough clearance? At the least code requires 3'6".

 

[ArCal]

Thanks for your response. The inverters are going to be moved.

 

[cowboyjwc]

A panel should definitely be considered grounded, and a typical inverter operates at more than 150V to ground, so how in this situation would 3ft be enough clearance? At the least code requires 3'6".

I argue this point all of the time with other inspectors. The section that everyone quotes also says, "....or maintenance while energized....". Just turn of the inverter. Is the inverter grounded yes, is the stucco wall that was there grounded, yes (Concrete, brick or tile walls shall be considered grounded. Stucco is concrete) A steel stud wall is grounded.

Look at the big picture. Guys are arguing over the cost of having to install an AFCI for a new addition, but don't have a problem making a guy tear out and move and already installed piece of equipment (yes I agree that it was a violation and I would have made them move it too.).

These are the kind of things that get me so wound up on this fourm.:happyyes:

 

[don_resqcapt19]

Two panels across from each other, even when they have grounded covers in place is a condition 3 installation. Look at 110.26(A)(1)(c). If two panels across from each other is not condition 3, then there would be no reason for the text in (1)(c).

 

[Marvin_Hamon]

The wording has always be problematic. Take the part of condition 1 that says

... or exposed live parts on both sides of the working space that are effectively guarded by insulating materials.

"Exposed live parts" and "effectively guarded by insulating materials" in the same sentence? If it's insulated then it's not exposed in my book. Maybe they are trying to describe conductors, an exposed live copper wire effectively guarded by a coating of insulating material.

 

[c_picard]

In my experience the only time an inverter needs service or maintenance some troubleshooting is required, energized...and by the 'just shut it off' logic we wouldn't need any working clearance anywhere.

 

[jaggedben]

The solar disconnect is a switch enclosure that cannot be de-energized during the day except by disconnecting the solar outputs on the array.

I really don't know how to interpret whether it satisfies condition 1 or 2 to leave the cover on the solar disco while working on the panel, or vice versa. But if it does not, then the only options are a) to get on a ladder and disconnect the solar outputs on the array, b) to only work on the equipment at night, or c) to move the equipment. How are you going to ensure people do (a) or (b)? It seems the only thing that unequivocally satisfies the code is (c).