John Pink G8MM commented as follows on my concerns for RFI from Solar that can negatively affect amateur radio operations:

*From:* john_pink *Sent:* Monday, May 07, 2018 12:02 PM *Subject:* RE: NEC 2017 codes of practice.

Bob, I read with interest your comments on the implications of NEC 2017. You said 'I hope I am not being alarmist' - I don't think you are - however you are tackling the issue on the wrong front.

The issue that you need to raise concerns the 'standards' that govern the interfaces between panels and optimisers - and any other ancillary equipment. There are IEC and IEEE standards that state the permissible levels of emission from the ports of these equipment, and the frequencies they use The standards are for the most part derived from standard agreed by CISPR.

As a contributor to CISPR through my work at British Standards Institute, and CENELEC in Brussels, I am aware of many licenced radio amateur from the USA who are involved in this work. In fact the lead representative for the USA on the subject of harvesting of solar energy is an active licensee. He is also involved with all aspect of Near Field charging of vehicle - another topic which should cause radio amateurs great concern.

I would recommend two things. Firstly that you encourage ARRL to increase its support for this important and valuable work, this may means financial support for the representatives, since the meetings are held around the world. ARRL need to sponsor 'experts' to ensure that the cost of travel is reimbursed. ( RSGB has been very generous in this respect). Secondly, find a way, if this does not already exist, to become involved in NEC affairs - it should be possible to have ARRL representation involved in their work. The objective is to ensure that 'best practice' is used on all and every installation of Solar harvesting schemes.

To summarise, the steps should ensure that the items of equipment (apparatus) are compliant with international standards that are designed to protect radio services, and then ensure that the equipment are installed in such a way that they do not negate compliance with the standard. For example, if the equipment is connected with twisted pairs in order the meet the compliance test - the installer must follow the same practice - and so NEC 2017 (or later versions), must make that clear.

Since every authorised installer should carry and be checked against the NEC installation practice, things will get better. However, I acknowledge that best practice is followed when safety issues are concerned - but rarely are rarely understood when EMC matters are important, and that it what you have to get across with NEC - and we have to get across here in Europe, where we face exactly the same challenge.

All of this is an international effort, because for the most part Solar harvesting equipment is manufacturer around the world. Here in Europe the systems come from China or Germany. Which means that it may be compliant with CENELEC requirements to carry the ubiquitous CE mark. Note that little word 'may', by which I suggest that there are ways around the compliance system - just as there are ways around FCC marking.

CISPR - Special International Committee for Radio Interference, affiliated with International Electro-Technical Commission (IEC)

CENELEC European Committee for Electrical Standards

I hope this helps - do let me know if I can provide any additional background.

John - G8MM, F5VKU