PVI 1800/PVI 2500
Installation and Operation Manual
7
The heat sink serves to conduct away heat generated from energy losses in the power electronics. Internal
temperature regulation provides pr otection against excessively high temperatures inside the PVI 1800/PVI
2500. The maximum power processed from the PV array is automatically reduced to limit excessive inverter
temperature.
The PVI 1800/PV2500 will only operate in parallel with the utility grid. AC grid monitoring is done by
microcontrollers set up to meet the requirements of UL1741. This includes grid voltage or frequency
fluctuations outside of the required limits, anti-islanding and other limitations and requirements, which
ensure that the inverter shuts down immediately if the grid goes down, or if the grid gives surges, sags,
changes frequency or otherwise shows signs of instability. If this happens, the inverter will check the grid
and reconnect to the grid 5 minutes after the grid is back to normal. (The display then shows: “Waiting for
restart”.) D isconnecting from the grid is important to protect the electrical and utility line workers who may
be working to restore the grid as well as electricians working at a site with PV systems.
Power grid faults that will cause the PVI 1800/PVI 2500 to isolate itself from the power grid:
•
AC grid voltage
The grid voltage must not go outside the range of +10/-12% of the nominal 240 or 208V AC grid
voltage. The inverter will isolate itself fr om the power grid if these limits are exceeded either way. The
PVI 1800/2500 will automatically detect 208 or 240VAC grid connections and disconnect if that grid
voltage goes outside the +10/-12% window for this voltage.
•
AC grid frequency
The power grid frequency can be within a range of +0.5Hz, -0.7Hz of the nominal 60Hz grid frequency.
The inverter will isolate itself from the power grid if these permitted limits are exceeded either way.
Another important safety feature is galvanic isolation of the utility grid and the PV array as well as ground
fault detection and interrupt (GFDI) of the PV array. The PV array negative is grounded inside the inverter
(and must not be grounded at any other point).