Surge Performance; Islanding Protection - Conext XW+ 6848 NA Owner's Manual

Surge Performance

Islanding Protection

975-0240-01-01
Unlike many other inverters, the Conext XW+ helps stop voltage from sagging
dramatically during surge conditions. The Conext XW+ handles surges of over
twice its rated output power with only a minimal drop in output voltage for limited
periods of time.
Islanding protection is an essential safety feature that helps reduce harm to those
working on the utility grid from a distributed energy source such as the Conext
XW+. Islanding protection also helps to prevent loads connected to the Conext
XW+ from being damaged by a fluctuating utility grid input. The Conext XW+
uses proprietary positive feedback control to achieve anti-islanding operation
while maintaining low total harmonic distortion at the grid connection. Default
software settings are programmed into each Conext XW+ at the factory so that
they comply with applicable safety regulations (such as IEEE 1547 and UL 1741
in North America).
In some instances it may be desirable from both a utility and a customer point of
view to adjust the default anti-islanding settings. For example, the Conext XW+
may experience "nuisance trips" if the grid is weak and the voltage falls outside
the allowable range specified by regulations. It may be difficult for a utility to
adjust the grid to stop this problem. With permission from the utility, the factory
settings may be changed to allow the Conext XW+ to operate over a wider grid
voltage range. These settings must only be changed by qualified service
personnel using a special software application (Conext Configuration Tool, Order
# 865-1155-01) provided by the manufacturer.
While exporting energy, the Conext XW+ continuously monitors the utility grid
voltage and frequency. If the grid voltage or frequency move beyond the Conext
XW+ default ranges (for example, during a power surge or outage) the Conext
XW+ stops exporting energy through AC1 and disconnects from the utility. If
disconnected due to a grid voltage disturbance, five minutes is the non-
adjustable minimum reconnect time during which the Conext XW+ does not
export energy through AC1 to the grid. The Fault light on the Conext XW+
information panel will indicate a utility fault. No fault code appears on the three-
character display because the fault is with the utility grid, not with the Conext
XW+.
In addition to the information panel, the Conext System Control Panel indicates a
utility fault with the Fault light and also displays a fault message on screen (faults
F23 to F40 are utility faults—see Figure 4-6, "Fault Messages" on page 4–19).
The fault cannot be manually cleared. Utility faults will clear automatically when
the utility grid voltage and frequency return to within the ranges programmed into
the Conext XW+. If grid support is enabled and the utility voltage and frequency
come back within tolerance, the Conext XW+ information panel displays a
countdown timer for five minutes until the Conext XW+ can start interacting with
the grid again.
Operation
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