Guide to device status indicators

June 2016
Monitoring the grounding system

SAFEGROUND® incorporates a visual indication that identifies with the correct protection offered, as well as other information

In order for the protection to work properly, the correct status of the grounding system in an electrical installation is essential, for the safety of both equipment and people. No earth, no protection.

The SAFEGROUND® indicator (LED) provides information about correct wiring, about the presence of an adequate path to ground to effectively discharge overvoltage energy, as well as other information relevant to the safety of the installation.


Effectiveness of protection (green - yellow - steady red)

The standard display with no incidence in the system is green. The green indicator shows that the protector is properly installed and the protection is operating with maximum effectiveness (“GREEN FOR GO”).

Yellow or steady red indicators do not necessarily mean there is a risk in the installation, but show that the effectiveness of the protection is impaired.

No ground (flashing red):

No ground connection. The surge protection loses all its effectiveness. Check the PE wiring of the SPD

Unless it’s just due to a fault in the protector PE wiring, you should consider maintenance actions on the entire grounding system for safety’s sake.

Live and neutral reversed (flashing yellow):

Indicates an error in the SAFEGROUND® connection. As is the case with other elements of an installation, the surge protection of live and neutral lines are not the same and are not reversible. Reversing them could result in inadequate protection and risk.

This is especially important in the case of a single phase protector, because in a 3-phase device, accidentally connecting a varistor between two phases causes it to reach its end of life, and would warn that an error has occurred; but in a single phase system there is no information apart from that provided by SAFEGROUND®.

Permanent undervoltage <195 V (flashing green-yellow)

Installation voltage well below the rated voltage of 230 V over a prolonged period affects the proper functioning of electronic equipment.

Permanent overvoltage >275 V (flashing red-green)

A surge protection device operating continuously well above its rated voltage receives heavy wear that can dramatically reduce its useful life and that of other equipment. It may also indicate that two phases have been connected between the device’s NEUTRAL terminal and the adjacent PHASE; so this is also a case of faulty wiring.

High neutral-ground voltage (flashing yellow-red)

A high voltage between neutral and ground may be a sign of an installation fault (derivation of phase to ground, no connection between neutral and ground, phase imbalance), and is a potential risk for the installation.