S
P
E
C
I
A
L
S
E
C
T
I
O
N
Address connectivity issues to reduce trips to solar sites
Y
ou’re a solar installer, not “the IT guy,” so why spend time dealing with connectivity issues, rebooting customers’ Wi-Fi networks? While real-time monitoring is an essential feature of today’s PV systems, communication between system monitoring devices and the customer’s router is often overlooked. Understanding the options for today’s connectivity—and making smart choices for your customers—can save you costly return visits to jobsites.
The challenge Relaying performance data from the
solar system to the customer’s computer or smart device and the manufacturer’s database involves constant, reliable communication between specialized components. The typical signal chain for communication links the solar array to the data collector, which is typically called a gateway—such as the APsystems ECU or the Enphase Envoy. The signals travel to the home internet router and onto various monitoring stations. It sounds straightforward, but differences in home size and layout can mean the gateway and router are separated, likely by walls and floors.
Bridging the gap Today’s solar customers have an almost bewildering array of choices (and acronyms) for linking the gateway to their router. There are Wi-Fi extenders or Ethernet cables, such as Ethernet-over-powerline (EoP), where wires used to distribute power inside homes also transmit digital data based on time division multiple access (TDMA) technology. You can even use old-
school CAT-5 or CAT-6 Ethernet cables. Each option has its particular strengths and weaknesses, and the right answer for one installation may not work for another.
Making the right choice Solar customers want reliability, from the solar modules to inverters to production. Connectivity should have the same level of reliability. Match your hardware choices to the size and layout of the house with proven technologies and products to ensure uninterrupted, around-the-clock monitoring. Keep in mind that the best choice will invariably be a hardline connection whenever possible. With potential signal disruption, a wireless connection will only ever be as reliable as wireless allows. Today’s wireless technology is incredible, but critical connectivity requires highly reliable communication devices. You simply can’t beat a direct, uninterrupted connection. Test each solution to find your ideal answer for each installation scenario, and remember the best solution is the one that requires the least follow-up once you’ve left the jobsite. SPW
CHRIS BARRETT
DIRECTOR OF ENGINEERING AND TECHNICAL SERVICES, APSYSTEMS
Install the wire box before the string inverter
C
ontractors can install string inverters with integrated, but separable, wire boxes more efficiently by installing the wire box first and then focusing on the inverters. Employing the appropriate skilled workers to align all wire boxes is essential to quickly complete DC and AC wire termination and connection. Once the wire boxes are in, lessskilled, lower-cost workers can install the inverters. This makes it easier to 4 4 SOLAR POWER WORLD
NABCEP section 3-17_Vs5.indd 44
3 • 2017
perform service because the inverter top can be removed for replacement with spare/RMA units, taking only a few minutes to make the swap. Also, consider solutions with easy connections. While some solutions require wires to connect the inverter to the wire box, CPS's string inverters simplify installation by requiring only four bolts to connect the inverter top to the wire box. Each inverter has a customized mating connector that provides all interfaces www.solarpowerworldonline.com
3/21/17 2:17 PM