Switchgear hot spot monitoring systems can use wireless and battery-free RFID sensors to avoid issues with batteries and wires in high voltage environments.

All distribution substations and nearly every factory have switchgear in place. These consist, among others, of busbars, instrument transformers, disconnectors, circuit breakers and panel boards.

Small technical issues result in huge disasters in switchgear due to the high voltage environments these equipment are installed in. Faults or failures in this gear can quickly evolve into conditions with high risk of short arc being generated, leading to catastrophic events such as power outages, loss of productivity and even fire or explosion.

Switchgear hot spot monitoring - short arc tests

Switchgear hot spot monitoring – short arc tests

Hot spot monitoring systems to detect potential issues

Most of the issues in switchgear appear where a busbar interfacing with a cable forms a poor connection. A bolt not tightened or even dirt between the connections causes a chemical reaction which in turn generates a point of resistance.

By monitoring these hot spots, maintenance systems can detect unexpectedly high temperatures and program corrective actions based on the information received.

Unluckily, temperature sensors cannot be wired – this would break the required electric insulation. Batteries are not a good solution either for the same reason.

Switchgear busbars

Busbars

RFID battery-free sensors for switchgear

UHF RFID sensors work reliably in high, medium and low voltage environments. Working in the 868MHz – 920MHz frequency band, there are no EMC issues with switchgear operation, granting a correct performance of the RFID system.

RFID sensors can be mounted on busbars and connectors to monitor temperature. Many different sensor tags can be used per rack so that maintenance crew can look at data and understand exactly which hot spot is creating the issue – which saves the time of checking all connections to make sure you correct the problem.

RFID sensors can provide hot spot data collection to switchgear manufacturers and users to manage these key and expensive assets. See an example of battery-free temperature sensor here: Electra-CT.