CONTRACTORS STATE LICENSE BOARD - Solar Panel Inspection

[mtnelect]

Did an inspection on a new solar system today that was not working. The homeowner and contractor were not speaking anymore to each other, so the homeowner filed a complaint. When we arrived the Solar Edge "Fault" indicator was on showing "3XBE" Arch Fault. So, we reset the system, and it went back online. Is the "Phanton" tripping affecting the solar systems now ? They have an "Energy Efficient" HVAC unit on the roof, which has been identified as causing problems with "AFCI & GFCI" because of the DC controlled hermetic compressor motors.

 

[solarken]

I would not think the HVAC noise could couple easily onto the PV conductors in or from an array, but I suppose it is possible if the conductors were in very close proximity.

 

[mtnelect]

It's not about having conductors close to one another that is causing the problem, it's about the higher frequencies that the electronic motor control circuits run on that interfere with the AFCI/GFCI. Most of the electronic motor control, and even electronic ballast circuits run on 600 MHZ. These signals are interjected into the premises wiring, where you now have "Phantom" tripping.

 

[mtnelect]

Correction ... 20 to 120 KHZ.

 

[jaggedben]

Really not enough info to guess from here. How do we know that the PV system didn't have an actual arc fault at one time or another? These things can be occasional or intermittent or dependent on weather conditions.

 

[mtnelect]

I would not think the HVAC noise could couple easily onto the PV conductors in or from an array, but I suppose it is possible if the conductors were in very close proximity.

They are both in emt, but both leave the roof together to the service side of the structure.

 

[solarken]

It's not about having conductors close to one another that is causing the problem, it's about the higher frequencies that the electronic motor control circuits run on that interfere with the AFCI/GFCI. Most of the electronic motor control, and even electronic ballast circuits run on 600 MHZ. These signals are interjected into the premises wiring, where you now have "Phantom" tripping.

But those circuits are connected to the AC premises wiring. The DC Arc Fault detection in SolarEdge systems is looking for the signature in the DC circuits. What I am saying is that noise on the AC side would not likely be seen on the PV (DC circuits) in the array. The DC and AC side of the inverter are isolated.

 

[jaggedben]

But those circuits are connected to the AC premises wiring. The DC Arc Fault detection in SolarEdge systems is looking for the signature in the DC circuits. What I am saying is that noise on the AC side would not likely be seen on the PV (DC circuits) in the array. The DC and AC side of the inverter are isolated.

Well, no, the DC and AC sides of a Solaredge are not isolated. But there are a lot of capacitors in there that I think would act as a filter.