This website uses cookies primarily for visitor analytics. Certain pages will ask you to fill in contact details to receive additional information. On these pages you have the option of having the site log your details for future visits. Indicating you want the site to remember your details will place a cookie on your device. To view our full cookie policy, please click here. You can also view it at any time by going to our Contact Us page.


Earth continuity monitor suits IS systems

The compact EMGUARD series of earth continuity monitors, from FDB Electrical, offers a wide range of earth continuity impedance settings, but is designed to enable parameters to be set beyond those specified by BS4444. The ultra-low power circulating in the pilot earth/loop (0.06W) means that it can be incorporated into intrinsically safe systems.

A advantage of the EMGUARD is said to be its high immunity against AC induced voltage in the earth conductor making it possible to accurately monitor long cable runs in excess of 1km without nuisance tripping.

The system features an extra conductor (pilot is utilised and this is connected via an end of line terminator to the framework of the machine at a different point to that of the earth conductor). A circulating current is passed round the pilot/earth loop which, when interrupted due to impedance increase, short circuit or open circuit (loss of earth) causes the opening of the supply to the machine.

Specifications include 110V, 240V or 440V 30-120Hz with an adjustable impedance range of 1 to 20 ohms. Response times on impedance increase are ±3 seconds and short circuit or open circuit ±1 second.

As well as precise impedance increase detection, the EMGUARD will also detect a short circuit between pilot and earth or open circuit of the earth conductor. The EMGUARD is also said to be fail-safe in operation.

The unit can be connected to any existing ‘active’ end of line terminator (diode or zener diode) and can be supplied complete with this type of terminator.

Contact Details and Archive...

Related Articles...

Print this page | E-mail this page

Electrical Products