Energy harvesting sensor monitors high-current distribution system safety

September 08, 2014 // By Julien Happich
Fires in electrical installations often occur due to hot spots caused by loose screws on bus bars, or loose terminal points; properly tightened screwed contacts are known to prevent the occurrence of overheating in high-current paths.

Aging effects in insulation, corrosion due to intrusion of dust or salt, and failure of fans or switching devices, as well as overload or irregular maintenance can also be the starting points for such accidents. But this risk can be significantly reduced by continuously monitoring the temperature at critical points within the switchgear, and the mNODE wireless sensor enables that

The energy-autonomous sensor mNODE from Micropelt can be retrofitted to new and existing switchgear to offer continuous temperature monitoring and increase significantly the safety and availability of such systems. The mNODE temperature sensor powers itself from the alternating electric field along the surface of the current-carrying conductor, using inductive energy harvesting. As little as 50A of load-path current generates enough energy for temperature measurement and data transfer.

The sensor can be clipped anywhere in the distribution system and the measured data is transferred with a license-free 2.4 GHz radio using IEEE 802.15.4 standard, even in a shielded industrial environment. The mNODE sensor captures the temperature measurements, transmits it to the NODE server (gateway) or directly to the control system PLC. The NODE server or the control system processes and stores the measurement data, performs plausibility checks, and calculates a trend analysis.

When the user-defined threshold is exceeded, an alarm message is sent to the monitoring station and the mobile phone of the responsible person. Such active health monitoring helps plant operators to detect and avoid unforeseen failures and costly interruptions in advance. With advance warning, internal or external specialists can be scheduled in time.

For testing and evaluating the temperature monitoring system, Micropelt provides a test kit consisting of three mNODE sensors, a USB wireless receiver, as well as the SCOPE evaluation software.

Micropelt GmbH;