Self-powered Sensor FAQ

Force applied from outside (kinetic energy) is converted into electrical energy. When a button is pressed or a door or valve moves, a magnet moves rapidly past a coil, changing the magnetic flux and generating an electromotive force (Faraday's law of electromagnetic induction). A force of 10 N produces up to 14 W, and that electricity sends a 10 mW low-power signal 3 times.

No wiring, wall work or battery replacement is needed. Because they are attached without changing existing facilities or equipment, installation time and labor are greatly reduced, and they can be installed in tight spaces and outdoors where power was not available. They are eco-friendly products that produce no spent batteries.

When the temperature rises, in the SMA type the SMA expands, and in the glass bulb type a special liquid inside the glass tube expands and breaks the tube, moving the sensor. That movement generates power to send a signal. The SMA type operates at approx. 75 – 85 ℃ or above, and the glass bulb type at approx. 90 ℃ or above.

Sensors, emergency bells and switches are power-free and wireless. The receivers, relays, Signal Monitors and Sensor Hubs that receive the signals are connected to a constant AC 220 V or DC 12 – 24 V supply (adapters provided for each model).

Self-powered emergency bells are fixed with double-sided tape or a dedicated emergency bell panel. Fire detection sensors are attached with double-sided tape or a dedicated bracket, and valve sensors are add-ons attached to existing valves. Receivers and relays are fixed by drilling into the wall or similar means.

With no batteries, they are not bound by battery life. 100,000 operations and RF signal transmission/reception were verified with a durability tester, and IP57 was confirmed by passing dust (IP5X) and water (IPX7) tests per KS C IEC 60529.

In IP57 testing, normal operation with no internal penetration was confirmed after 8 hours of exposure to dust (talc powder 50 – 75 ㎛) and 30 minutes of immersion. They are installed in outdoor switchboards, outdoor common facilities of apartment complexes and outdoor GIS at substations.

Sensor transmission range is approx. 100 m in open field with no obstacles. Each added repeater (MWSR2-900) extends it by approx. 1 km. Range may be reduced in places with many obstacles, such as steel structures, concrete walls and the inside of switchboards, so repeater positions are determined after reviewing site conditions.

Sensors transmit using FSK in the 920.7 MHz band, and repeaters, Signal Monitors and Sensor Hubs use both 920.7 / 447.9 MHz. Each sensor uses a unique ID, so there is no radio interference.

There are cases of integration with SCADA and PLCs via the RS-485 communication of the Signal Monitor and Single-window Monitor, relay contacts and IED (IEC 61850) dedicated monitoring panels, and the protocol is matched to the site system. Upon detection, alerts are given immediately via on-site beacon lights and speakers, PC screen pop-ups and text messages to registered staff.

We hold KC Radio (conformity registration), KC Electrical Safety Certification for the AC receiver and international explosion-proof certification (IECEx, Ex ib IIB T4 Gb). International certifications include FCC (6 products), Japan MIC, CE and PSE. Please contact us about fire protection product type approval (KFI) for each product.