Are PV modules getting too big for our standards?

How to limit the current from a PV module from Glen Morris on Vimeo.

AS/NZS 5033:2014 has an exemption to the requirement to have a switch-disconnector between the PV array and the PCE (inverter, charge controller or load) for DC Conditioning Units.

The input circuits between the PV modules and the d.c. conditioning units are not required to have load break switch-disconnectors provided the input to the d.c. conditioning units is arranged so that the following applies:
… (c) Each input is limited to 350 W maximum PV power at STC and a maximum input voltage no greater than ELV.”

However, back in 2014 maximum module size was around 250W and this 350W limit seemed to allow any single module to be connected to a DCU such as those made by SolarEdge, Tigo etc… now, just three years later modules are heading over 300W and some nudging the 350W limit already.Interestingly, module manufacturers such as those listed below, already required covering of the module with an opaque material to limit any current before connecting or disconnecting the plug and sockets of a PV module. This manufacturer’s requirement provides a safe way to attach modules >350W @STC to a DCU and still ensure that the power in the cables is kept below 350W.

Covering with an opaque material also allows a safe (and no plug/socket damaging method) to disconnect a PV module from a faulty DCU (has gone short circuit internally).

I would argue that since the intent of the standard is to limit the power supplying the DCU to <350W, if following manufacturer’s installation instructions and covering the modules before disconnecting plugs and sockets, then modules larger than [email protected] can be connected to a DCU and still meet the “no switch-disconnector on PV to PCE” exemption of clause 2.1.5.

List of module manufacturer’s who’s installation instructions require covering of the module with an opaque material:

*If you search the word “opaque” within these documents you will find the procedure to be universally applicable and acceptable.

350W DCU Limit Solution from Glen Morris on Vimeo.

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