Installation guide

Installation Guide RN3000US Jan13
13
lagging reactive current into the utility grid. This method has been proven by
independent test labs to effectively destabilize and disconnect from a balanced
island condition.
PV Insulation Fault Detection
Before the inverter connects to the grid, the Digiwatts system will detect the
isolation of PV+ and PV- to the ground. When the insulate impedance is less
than 1MΩ, the inverter will not function. After the inverter is connected to the
grid, the system will detect the residual current. If a residual current greater than
30mA is detected, the Digiwatts system will shut down and display a fault
condition on the LCD user interface display.
AC Overcurrent Protection
The system will detect the AC current real time. Should the AC current exceed
20 ampere, the Digiwatts system will shut down and display a fault condition on
the LCD user interface display.
Safety criterion
ETL is the standard applied by Electrical Testing Laboratories to the
Digiwatts system to certify that it meets the requirements of the
highest safety criterion of the USA and Canada.
The Digiwatts system has been tested and listed by ETL to meet the
requirements of UL1741 Static Inverters and IEEE 1547 Standard for
Interconnecting Distributed Resources with Electric Power Systems.
The Digiwatts system is also listed under CSA Std C22.2 No.107.1-01.