USER MANUAL
EarthGuard – EG-300
Australian Energy Research Labs
AER013 – Rev 1.1
21st July 2020
12
AER013 REV 1.1
When the EarthGuard is powered up, it will immediately check for insulation degradation between the
connected DC Poles Under Test and Reference Earth, reverting to periodic tests thereafter.
If a fault is detected, the red alarm LED will flash, and the integrated buzzer will sound until silenced with
the “Silence” button located on the front of the device.
Finding a Fault
If the EarthGuard has detected a fault, the red LED’s flash pattern will indicate which pole the fault has
been detected on.
2 Flashes
=
Positive Pole
4 Flashes
=
Negative Pole
This can be used to narrow down the potential location of the detected fault when troubleshooting.
Clearing a Fault
If a fault has been rectified, the “Re-Test” button located on the front of the EarthGuard device can be used
to immediately retest to the system to confirm the fault is no longer present.
After several seconds, the “All Clear” green LED should start blinking if the fault is no longer detected.
Simulating a Fault
If you would like to test the EG-300 has been correctly installed, the following method can be used with
extreme caution.
Firstly, isolate all power conversion equipment (PCE) from the EarthGuard, disconnecting any chargers,
inverters, and generators from the battery bus.
With both the EarthGuard and the system completely powered down
, and
all equipment isolated
from the device
, a simulated fault can be introduced by wiring a path from either the DC+ or DC- to
Reference Earth with a
100kOhm
Resistance in-line.
Upon reapplying battery voltage to the DC+ & DC- sense wires and either USB or 12V power to the
EarthGuard, a fault alarm will occur within a few seconds, provided the device is correctly installed and
configured for the relevant battery voltage.
Operation
CAUTION – Potential Hazard
Earth Faults can damage PCE and connected components. Please consult the
manufacturer of the PCE in use prior to simulating an Earth Fault. AERL takes no
responsibility for any damage caused as a result of the instructions below.
