Disconnect from electrical main panel

[Andres Arias]

During the installation of residential photovoltaic PV systems in New York City, we used to install a disconnect between the AC subpanel (that controls the strings of the solar modules installed on the roof) and the electrical main panel of the house. As a thumb rule, we always proceed with installing that disconnect at no more than 10 feet from the electrical main panel, either inside or outside of the building (house). However I would like to know if the 10 feet rule is clearly stated in a any electrical code in NYC, as checking in NEC the 10 feet is not stated in the 690.13; just saying that the disconnecting means should be readily accesible.

Thank you

 

[pv_n00b]

In the 2008 NEC that the NYC electrical code is based on, 690.14(C)(1) simply requires that it be readily accessible outside the building or inside at point of entry, no 10ft requirement. The 10ft requirement may be coming from the NYC electrical code or the utility. Utilities often want the PV disconnect near the service disconnect. I don't have a copy of the NYC electrical code but I assume you do and since it's based on the 2008 NEC just look for any local amendments to 690.14(C)(1).

 

[Andres Arias]

Thank you. You are right. NYC local regulations state the 10 feet rule. See attached

 

[jaggedben]

Thank you. You are right. NYC local regulations state the 10 feet rule. See attached

That doesn't state a requirement for a disconnect "between the AC subpanel (that controls the strings of the solar modules installed on the roof) and the electrical main panel of the house" like you asked. There is no general NEC requirement for such a disconnect.

Note the list of equipment at the top of 690.15 does not include panelboards or other equipment (such as an Enphase combiner) besides what is listed.

A requirement for a disconnect within 10ft of a meter or service panel would almost always be a utility requirement.

 

[jaggedben]

That quote sure doesn't look like the 2008 NEC. It would seem that at least article 690 in the NY Electrical code is based on the 2017 NEC.

 

[pv_n00b]

NYC is currently in the process up updating its code to be based on the 2020 NEC. The active code is based on the 2008, they are one of the laggards in the US. https://www.ecmweb.com/national-ele.../new-york-city-modernizes-its-electrical-code
NY State has a different code from the city. You need to be very careful to know what code applies to the project you are working on.
The 2023 NEC 690.15 is for disconnects that isolate equipment, it's not for the PV system disconnect. The PV system disconnect is in 690.13.
In the 2008 NEC the system disconnect location is called out in 690.14(C)(1):

(1) Location.
The photovoltaic disconnecting means shall be installed at a readily accessible location either on the outside of a building or structure or inside nearest the point of entrance of the system conductors.
Exception: Installations that comply with 690.31(E) shall be permitted to have the disconnecting means located remote from the point of entry of the system conductors.
The photovoltaic system disconnecting means shall not be installed in bathrooms.

No reference to a 10ft requirement.