Specialised Mining Supplies

Earth Continuity Monitor

This ECM monitors an earth wire or any other cable by a split-core toroid around the cable. It is DIN-rail mountable.
The toroid is used to measure the voltage while injecting a small current thereby measuring the loop resistance.
It is usually mounted around the earth wire.
The ECM then monitors the resistance in the Earthwire - Neutral loop.

The ECM can also monitor the earth fault current (settable for 1 - 10A, if enabled)

The unit will close a relay contact and optionally send SMS's or miss-calls through the built-in Celtifier
when the cable resistance increases suddenly or when the system is being tampered with.
An RS485 connection is provided and Modbus protocols are supported.
Trip time for cable damage, earth fault and other parameters can be set by built-in DIP switches.

ECm with backup battery

A battery charger is also built-in to allow an external back-up battery to be connected.
With a 1.2Ah sealed lead-acid battery connected the ECM will run for another 6 hours after power failure
while the trip indicators will blink for another few days.

The SMS's for cable damage will be repeated every 30 min. or as configured up to a settable max. no. of SMS's
or until the fault condition is cleared.

The status can also be interrogated by SMS.

The indicators show: ECM running (blinks on fault) , GSM active, battery charger on,
power independant blinking: tripped on cable damage, tripped on high earth fault current.


Monitor resistance of earth wire and improve safety

By E.J. Häussermann, Mercutech and J Warwick, Jojen Supplies

read this article here