Specifications Sheet

Key Features and Benets
GFPD-600V GFPD-150V
G
ROUND
F
AULT
P
ROTECTION
D
EVICE
G
ROUND
F
AULT
P
ROTECTION
D
EVICE
Morningstar’s Ground Fault Protection Device (GFPD) is an innovation for ground fault detection and interruption
for the photovoltaic (PV) industry. It has greater sensitivity and better isolation while maintaining the bond to earth
ground. Ground fault protection is used in electrical systems to prevent current from following any unintended paths
during a ground fault. Morningstar’s GFPD has been designed to meet the ground fault protection requirements of
the US National Electric Code (NEC) for grounded PV systems.
How it Works: A GFPD needs to detect any stray current and interrupt (break) the circuit until safe operation can be
restored. A current imbalance between the primary positive and negative PV conductors entering the controller or
inverter may indicate a ground fault condition. Morningstar’s GFPD will detect this condition and break the circuit on
both the positive and negative legs. Disconnecting both poles ensures interruption of the ground fault current.
Other ground fault detection/interruption products break the bond to the grounded conductor. When this occurs,
not only is the earth bond compromised, but the battery and DC loads can also be left ungrounded and floating. For
a negatively grounded system this means that the negative side of the battery and loads can float to negative Voc in
relation to ground. Morningstar’s GFPD better isolates the array from the battery and loads, while maintaining the
bond to ground.
 Simple and Flexible Installation
• Side or below flush mounting with coupling hardware
included
• Feedback signal wire harness comes pre-wired
• Includes fused battery cable for power
• Compatible with other supplier’s PV controllers and
inverters
• For positive or negative grounded PV systems
 Greater Sensitivity
• More precise than fused ground fault protection
• Activates starting at 300mA compared to 1A for
alternative solutions
• Sensing device provides consistent, accurate
measurement
 Maintains the bond to earth
ground
• Normally grounded components (conductors,
controller, battery and DC loads) will not be left floating
• Avoids problems of other ground fault protection
options, which can allow the battery and load to float
to PV array voltages in relation to ground
 No Fuses
• Avoids problematic replacements of fuses, which are
often unavailable at remote sites
• Uses high quality breaker switches that continue to
operate after ground fault interruptions
 Safety Features
• Breaks the connection to the PV array during a fault
condition
• Leaves the battery and DC loads grounded under all
conditions. Alternative ground fault solutions require a
warning label on the battery to note that “dangerous
voltages are present”
• Features audible and visual indications
• Includes push-button test circuit
 Better Isolation
• Disconnects both the positive and negative conductor
• Completely isolates the ground fault from the
controller, battery and loads
 Supports both single controller
and multiple controller systems
• Will only shut off affected controllers while maintaining
the system earth bond
• All loads will continue to operate safely with the battery
remaining bonded to the ground
• Multiple controllers and GFPDs may be added later on
an as-needed basis