AFCI

[Joe Crecca]

I had a conversation with our leasing company. They asked us if we were installing AFCI protected inverters. I said no obviously didnt know that the rule had a set standard and was being implemented. I am only aware of one listed inverter for AFCI and that is the SMA TL. Was wondering if anyone was aware of the code being enforced, or where it stands as of now. Thanks in advance.

 

[augie47]

This was added in the 2011 Code and may well be enforced in any jurisdiction that has adopted 2011:

690.11 Arc-Fault Circuit Protection (Direct Current).
?

690.11: Added new requirement covering listed dc arc-fault circuit protection devices in PV systems operating at 80 volts or greater.


Photovoltaic systems with dc source circuits, dc output circuits, or both, on or penetrating a building operating at a PV system maximum system voltage of 80 volts or greater, shall be protected by a listed (dc) arc-fault circuit interrupter, PV type, or other system components listed to provide equivalent protection. The PV arc-fault protection means shall comply with the following requirements:

(1)

The system shall detect and interrupt arcing faults resulting from a failure in the intended continuity of a conductor, connection, module, or other system component in the dc PV source and output circuits.

(2)

The system shall disable or disconnect one of the following:

a.

Inverters or charge controllers connected to the fault circuit when the fault is detected

b.

System components within the arcing circuit

(3)

The system shall require that the disabled or disconnected equipment be manually restarted.

(4)

The system shall have an annunciator that provides a visual indication that the circuit interrupter has operated. This indication shall not reset automatically.

 

[jaggedben]

Here in California the 2011 code doesn't take legal effect until the end of this year (in the form of the 2013 California Electric Code). Presumeably because of this, none of the jurisdictions I've worked in have mentioned it so far.

See the last paragraph of 90.4. If you can't actually obtain an AFCI inverter or separate DC AFCI device for your system specs, your AHJ should give you a pass.

I believe the SMAs are only just hitting shelves right now in most places. I think a few other inverters are coming with AFCI but off the top of my head I don't remember which.

 

[Joe Crecca]

thanks for the replies, so what I really need to do is contact the AHJ and ask what NEC is compliant in the area for this matter. I am not changing my invertes on any job just yet. But I dont want to eat or hold onto inverters that I have already purchased.