Heating/cooling relay with 4 channels, 1 NO contact per channel 4A/250V AC, potential free from the power supply, with DX technology. Bidirectional. Only 0.1 watt standby loss. Modular device for DIN-EN 60715 TH35 rail mounting. 1 module = 18mm wide, 58mm deep. Connection to the Eltako-RS485 bus. Bus cross wiring and power supply with jumper. Patented Eltako Duplex technology allows you to switch normally potential free contacts in zero passage switching when 230V A/C voltage 50Hz is switched. This drastically reduces wear. To achieve this, simply connect the N conductor to the terminal (N) and L to K(L). This results in an additional standby consumption of only 0.1 watt. When all 4 relays are switched on, a power of 0.7 watts is required. If supply voltage fails, the device is switched off in defined mode. This heating/cooling relay assesses information about wireless temperature controllers or sensors. Possibly supplemented by window/door contacts, motion detectors, window handle sensor FFG7B-rw and wireless pushbuttons. As an alternative to a wireless temperature controller, the temperature information on the set and actual values can be obtained from a Professional Smart Home controller.