GARD – Installation, Operation and Maintenance Manual
A l e n c o n S y s t e m s L L C - P a g e
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4
Detect and Isolate Ground and Arc Faults in Your PV Array
4.1 The Ground & Arc Rapid Disconnect Unit (GARD)
Alencon’s
G
round
and
R
apid
D
isconnect
unit, the
GARD
, is a unique solution for detecting harmful
ground and arc faults in your PV array at the string level. When detecting these faults, the GARD
automatically disconnects the faulty string. The GARD communicates with the customer’s SCADA
system via a
MODBUS RTU
communication link.
The GARD also offers the ability to rapidly and safely disconnect PV strings with either a local or
global E-STOP switch or via remote MODBUS commands. The GARD can be deployed as a
standalone device or in conjunction with Alencon’s String Power Optimizer and Transmitter – the
SPOT. Additionally, it can be used with or without remote communications.
The GARD can be installed in new PV systems or as a retrofit to existing solar plants.
4.2 Unique Features & Benefits of the Alencon GARD
Detect and isolate potentially dangerous ground leakages and arc flashes at the string level
Quickly turn off faulted strings
Reduce O&M costs by determining precisely where faults are occurring in a PV array
Maintain power production during maintenance by not having to shut down entire combiners
or arrays when repairing electrical faults
Remote Control via an external E-STOP and Modbus Commands
