Standard for photovoltaic inverters provides relief


The CISPR 11 standard with the catchy title "Industrial, scientific and medical equipment - Radio disturbance characteristics - Limits and methods of measurement" covers power electronic devices such as solar inverters. Although there were voltage limits for conducted emissions at the mains port in the past, limits for the connections to the solar cells were missing.

After a positive vote of the international standard bodies, CISPR 11 Ed.6.0 is about to appear officially. In this new version limits finally apply (74 dBuV between 500 kHz and 30 MHz) for the DC terminals, in particular for systems up to 20 kVA in residential environments (Class B).

Through intensive work of the IARU in the standardization bodies during the last 5 years this goal has now finally been achieved. "But the work in terms of photovoltaic does not end here," said Thilo Kootz, DL9KCE, EMC Coordinator of IARU. “The limits are currently being validated by checking the emissions of installations in a computer model. It is possible that limits will be readjusted after this validation phase. With the current limit, however, a reasonable protection for shortwave reception has already been achieved."