SR81 solar water heater intelligent controller for split-type solar energy systems. All devices adopt industrial grade standard for reliable operation in cold, high temperature, and humid environments. Features a clock chip for accurate timing control. LCD liquid crystal display with stable and reliable performance. Easy installation. Main Functions: Single system for one collector and one water tank. LCD display. CLK time setting. THET timing auxiliary heating. CIRC water end circulation pump with three-time temperature and time control. PWD password input. LOAD water tank heating setting. COL collector function. OCEM collector emergency shutdown. OCCO collector cooling. OCMI collector minimum temperature. OCRF collector antifreeze. COOL cooling function. OSTC tank cooling. OHDP heat transfer function. AH automatic temperature adjustment. BEEP buzzer fault alarm. MAN manual function. BLPR blocking protection. OTDI high temperature function. Flow monitoring and pump idling protection. UNIT conversion between Celsius and Fahrenheit. RET reset. PASS password setting. M.H manual heating. Economic model. Manual start with water circulation pump. Holiday function. Protective function. Power failure memory protection. Screen protector. Power input: AC 100-240V ~(50-60Hz) Rated pulse voltage: 2.5KV Installation: Wall mounted Operation: 10 push buttons on the front panel Protection category: IP40 Electric heating: 1500W Ambient temperature: -10 to 50°C Temperature measurement accuracy: +/- 2°C Temperature display: 0.1°C Collector temperature range: -10 to 220°C Water tank or pipeline temperature range: 0 to 110°C Input signal: 1 PT1000 temperature sensor input, 4 NTC10KB=3950 temperature sensor inputs, 1 rotary vane electronic flowmeter (FRT) Output signal: 3 electromagnetic relays with maximum switching current 2A Color: White Material: Plastic Size: Main controller dimensions 200 x 140 x 43mm PT1000 sensor: 6 x 50mm Line length: 1.5 meters NTC10K specification: 6 x 50mm Package Contents: 1 x Controller 1 x English manual 1 x PT1000 sensor 2 x NTC10K sensors 1 x 10A power cord Only the above package content is included. Other products are not included.