Casualty accidents have frequently occurred due to installation of earth wires upon energization and closing of mains switch with earth wire connected in the electric system in recent years. In order to avoid
occurrence of casualty accidents due to closing of mains switch with earth wire connected, a “five steps protection” system has been installed in substations.

A series of logic judgments and electric and mechanical interlocking measures have been adopted and worked effectively to prevent accidents arising from misoperations. The current “five steps protection” system of substation mainly works to prevent misoperations of equipment furnished with an earthing knife switch. However, it is not capable of effective management and on-the-fly monitoring of temporary earth wires and earthing points. It is impossible for on-the-fly monitoring of the working state, earthing state and earthing position of the earth wire in the substation. The operator has to check them personally in the field. If any construction work has to go on for long in the substation, the temporarily connected earth wire may be easily ignored upon shift change or emergency closing of mains switch, hence creating a critical safety hazard. The real-time monitoring system of earth wire is primarily designed for the temporary earth wire and temporary earthing point in a substation.
IOT technologies are adopted for electronic management and real-time on-the-fly monitoring. The system can display the earthing point, earthing state and connection condition of the temporary earth wires upon connection and disconnection thereof.

1. Operating record of earth wire warehousing conditions; this feature
enables the recording of the name, code and time of the earth wire
delivered into/off the safety tool room.

2. When the earth wire connection state indicator shows arrival of the
earth wire at the site, the field reader will read the RFID label to
determine the code and current state of the earth wire (from
disconnected to connected or the opposite) and transmit the data to the background management software via the wireless network.

3. Display of earthing position: The background management software
automatically judges the earth terminal that sends the data according to
the content of received message, comparing the data and displays on
the software interface the earth wires and the earthing terminals
connected therewith.

4. Operating records: Recording of earth wire warehousing and
connection conditions and the system events

5. Alarm functions: The system includes multiple levels of alarms which
are applicable for different types of alarm events.