{"product_id":"m-ller-sc28-21-pro4-2-channel-din-rail-time-switch-bluetooth-programmable","title":"Müller SC28.21 Pro4 2 Channel DIN Rail Time Switch - Bluetooth Programmable","description":"\u003ch5\u003eDescription\u003c\/h5\u003e\n\u003cp\u003eThe Müller SC28.21 Pro4 is a 2-channel DIN rail time switch with Bluetooth programming via iOS and Android smartphones. Each channel switches up to 16A at 230V AC, providing independent control for two separate circuits from a single DIN rail module. The switch uses zero-crossing technology to reduce electrical noise and extend the life of connected LED loads up to 600W per channel.\u003c\/p\u003e\n\u003cp\u003eDesigned for distribution boards in residential, commercial and light industrial installations, the SC28.21 Pro4 controls lighting, heating, pumps, ventilation and appliances on daily or weekly schedules without requiring a fixed central controller. The Bluetooth connection allows programming from the Müller app without opening the distribution board enclosure, and the switch retains its program during mains power loss with a 10-year battery reserve.\u003c\/p\u003e\n\u003cp\u003eThe module occupies 2 DIN rail spaces (36mm width) and measures 108mm height by 65mm depth, fitting standard UK consumer units and distribution boards. The LCD display shows the current time, next switching event and channel status at a glance. The orange catch at the base indicates Bluetooth connectivity and the unit carries the Made in Germany mark with model number SC28.21 Pro4 on the front face.\u003c\/p\u003e\n\u003ch5\u003eSpecification\u003c\/h5\u003e\n\u003ctable class=\"spec_table\"\u003e\n\u003ctr\u003e\n\u003ctd\u003eProduct Net Weight (KG)\u003c\/td\u003e\n\u003ctd\u003e0.16\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eProduct Gross Weight (KG)\u003c\/td\u003e\n\u003ctd\u003e0.18\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOuter Gross Weight (KG)\u003c\/td\u003e\n\u003ctd\u003e0.18\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eProduct Length (mm)\u003c\/td\u003e\n\u003ctd\u003e41\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eProduct Width (mm)\u003c\/td\u003e\n\u003ctd\u003e108\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eProduct Height (mm)\u003c\/td\u003e\n\u003ctd\u003e65\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOuter Length (mm)\u003c\/td\u003e\n\u003ctd\u003e41\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOuter Width (mm)\u003c\/td\u003e\n\u003ctd\u003e108\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOuter Height (mm)\u003c\/td\u003e\n\u003ctd\u003e65\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\n\u003ch5\u003eDownloads\u003c\/h5\u003e\n\u003cp\u003e\u003ca href=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0729\/8993\/3835\/files\/products_SC2821PRO4_datasheet.pdf\" target=\"_blank\"\u003eProduct Specification Sheet\u003c\/a\u003e\u003c\/p\u003e\n\u003cp\u003e\u003ca href=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0729\/8993\/3835\/files\/manual_SC2821PRO4.pdf\" target=\"_blank\"\u003eProduct Manual\u003c\/a\u003e\u003c\/p\u003e\n\u003ch5\u003eFrequently Asked\u003c\/h5\u003e\n\u003cp\u003e\u003cstrong\u003eHow is the time switch programmed?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eThe SC28.21 Pro4 is programmed via Bluetooth using the Müller app available for iOS and Android. The app connects to the switch when you are within range of the distribution board, allowing you to set daily or weekly on\/off schedules for each channel without opening the enclosure or touching the unit.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eHow many DIN rail spaces does it occupy?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eThe module occupies 2 standard DIN rail spaces (36mm width). It fits standard UK consumer units and distribution boards with 35mm DIN rail mounting.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhat happens during a power cut?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eThe SC28.21 Pro4 has a 10-year battery reserve that maintains the clock and stored programs during mains power loss. When mains power returns, the switch resumes normal operation without needing to be reprogrammed.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhat loads can each channel control?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eEach channel is rated at 16A on 230V AC mains, handling resistive loads like heating and incandescent lighting up to 3,680W. For LED loads, the zero-crossing switching supports up to 600W per channel. Inductive loads such as motors may require derating.\u003c\/p\u003e","brand":"Sangamo","offers":[{"title":"Default Title","offer_id":45294175584523,"sku":"SC2821PRO4","price":131.99,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0729\/8993\/3835\/files\/SC2821PRO4_4e26108b-4dbd-4c51-b6f0-7e122e08b25f.jpg?v=1714669127","url":"https:\/\/niori.co.uk\/products\/m-ller-sc28-21-pro4-2-channel-din-rail-time-switch-bluetooth-programmable","provider":"Niori","version":"1.0","type":"link"}