NFPA 70, the National Electrical Safety Code, describes requirements for rapid shutdown of photovoltaic arrays in Article 690.12. Most local Authorities Having Jurisdiction (local building code board
Apology to the reflector - I conflated NESC, an IEEE standard, with NEC, which is the NFPA 70 document. Article 690 is part of the NEC, not the NESC. Too many standards on the brain...... 73, Mike, K
Hi Gordie, I advise separating the decision about your PV array DC bus voltage from the decision about the battery bank bus voltage. The Trina PV modules you acquired have an open-circuit voltage of
No flames, Randy - just a request for the source of the statement attributed to Ms. Rosenworcel, the FCC chairperson. I can't believe any FCC senior appointee would make a qualitative or quantitative
I have not seen this type of spectrum in the wild, Alex, but the stepped frequency dithering of each 'carrier' component in the spectrum suggests an SMPS which is inadvertently modulating an RF carri
Agreed, David (K1TTT) - the step frequency variation could readily be due to the FFT computation interval while the frequency wobble of the spectral lines occurs continuously because of drift in the
The recent discussions on RFI due to solar photovoltaic systems induced me to read a bit more about the standards that Ed, W1RFI has described repeatedly. While by no means comprehensive, this pair o
Sorry, Ed! The link had context information indicating the original source in which I found it. The correct link is minus the ?context..... stuff. https://training.ti.com/fundamentals-emi 73, Mike, K
Thanks, Ken - it doesn't present that way in my email client, which may be part of the issue. Glad you saw through the fog! 73, Mike, K8CN ________________________________ From: Kenneth G. Gordon <kg
Hi Michael, All inverters, whether centralized or distributed (microinverters on each module of the PV array) have an accepted input voltage range over which they will perform the DC to AC conversion
Thanks, Bob, for raising that question again. The maximum solar irradiance on the Earth's surface is about 1300 Watts/square meter. A full moon produces about 1 mW/square meter, six orders of magnitu
It's important to note that the Solar Edge power conversion architecture uses two stages: the DC to DC converters that are attached to each PV module in an array, and the central inverter that conver
Hi David, I studied the links you provided. I did not see specifications for RMS noise voltage or frequency bandwidth. Indeed, these specifications make no sense for a battery pack, which the Super B
If my reading of that table from the source Joe linked is correct, the China transmitter on 7.195 MHz has a TX power of 50 watts. Seems unlikely to provide S9 + 10 dB signal or larger in west central
Correction to my last post - there are many SW broadcast stations on 7.195 MHz with 50 kW and up TX power. I put the table in frequency rank order and looked at the many stations on 7.195 MHZ. An unm
This article from IEEE Spectrum does not bode well for RFI levels generally: https://spectrum.ieee.org/wireless-charging With fundamental switching frequencies moving from the few hundred kHz range i
Hi Tom, ZNShine produces the photovoltaic modules, not the power converter electronics that are the source of RFI. You need to speak to the system installer to find out what conversion architecture w
Hi John, I can't speak specifically to POE lighting, but the New Hampshire ARRL RFI hunter team did earlier this year find a case of a noisy POE injector in a home security camera system. The injecto
Hi Jim (W6YA), Others may chime in with specific model recommendations, but I'll note that modern refrigerator/freezer units that attain a good Energy Star rating invariably use PWM control of air ci
Thanks for the detailed update, Don. It is a bit intimidating to think that resolution of similar RFI issues might require high-level intervention at the level of a major corporation's president's of