Technical Corner: Installing MICRO Inverters and Gaining Good Communication with the CDD Unit

This month Paul Baker, Customer Information Center Representative at Power-One, shows how customers can impove the communication between their AURORA MICRO inverter and their AURORA CDD by optimizing the signal strength.

“MICRO inverters communicate to the CDD unit over a radio frequency wireless link. With good signal strength the assimilation process can be completed quickly and easily, but as with any communication it is vital that the best conditions are put in place to achieve this good signal.

An improvement in signal strength can be easily gained by repositioning the aerials on the AURORA CDD. Radio signals travel horizontally and the radio antenna on the unit will readily receive these radio signals when the right hand aerial on the CDD, looking at the unit from the front, is not directly pointing upwards but at 90 degrees to the vertical plain. The left hand side aerial should be in the upright position as this is the aerial that receives the Wi-Fi signal.

The best location for the CDD is as close as possible to the inverters, though of course, the location must be readily accessible to the user and as close to the Wi-Fi router as possible. Obstacles between the CDD and the MICRO inverters will also degrade reception. Such obstacles are generally solid objects and include metal roof surfaces or other metal objects, metal-reinforced concrete and rebar, building frames, granite and other hard stone, bulletproof glass, some tinted glass, some reflective surfaces, or even particle board. The following table shows the signal degradation that these materials can result in:

Obstacle material

Signal degradation relative to an open field

Metal

Up to 100% (complete blockage of signal)

Metal-reinforced concrete

10-90% (depending on the amount of metal)

Stone, particle board, pressed cardboard

10-40%

Wood, plain glass

0-10% (little degradation of signals)

If such items are in the way, or if the CDD is far from the inverters, try relocating the CDD. Note that fog and rain can also affect signal transmission, but PV panels are not likely to be producing energy when it’s foggy or rainy.

So as you can see with good lines of communication the MICRO installation can be easily completed and the system can soon be in full production.”

If you would like to submit a question for one of the next newsletter editions, please contact aurora-academy.uk@power-one.com.