Alan,

I've worked with a large local PV installer to solve RFI problems, and I can vouch for the fact that it can be difficult to de-noise PV interters. the MPPT circuit is not analog and can turn the DC input lines into hash antennas, and as you stated, the inverter itself can put RFI on the 120/240 interconnect.

When I was in the market for PV equipment, I took a small battery operated emergency radio and visited several sites as well as showrooms of local vendors where they had demo systems. The quietest PV install I found used the SMA 3000US inverter. I just looked on-line, and the closest I could find to this model is now called the 3000TL (transformerless) so I cannot vouch for it's RFI characteristics.

I installed it using a combination of EMT and BX wiring to shield the input and output wiring, with twisted conductors in the conduit, adb BX having inherently twisted conductors. I see zero increase in my noise level due to the PV system from my 160M OCF which goes right over the house, so I can definitely recommend that model SMA. They are not the cheapest inverters, but as a student of switching supply design, I know the least RFI-generating topologies are not the cheapest, and good transverse and common-mode filtering is not cheap to implement at the power levels a PV system can operate.

Contact me if you need any other info.

Howie - WA4PSC
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to arch...@mail-archive.com

Reply via email to