SR81 Solar Water Heater Intelligent Controller, designed for split-type solar energy systems. All components are built to industrial-grade standards, ensuring reliable operation in cold, high-temperature, and humid environments. Equipped with a clock chip for precise timing control. Features an LCD liquid crystal display with a sleek design, stable performance, and easy installation, making it an ideal accessory for solar water heating systems. Main Functions: Single System (standard solar system with 1 collector and 1 water tank). LCD display. CLK time setting. THET timing auxiliary heating. CIRC water circulation pump with three-stage temperature or time control. PWD password input. LOAD water tank heating setting. COL collector function. OCEM collector emergency shutdown. OCCO collector cooling. OCMI collector minimum temperature protection. OCFR collector anti-freeze function. 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 dry-run protection. UNIT conversion between Celsius and Fahrenheit. RET reset. PASS password setting. M.H manual heating. Economic mode. Manual start of water circulation pump. Holiday function. Protective functions. Power failure memory protection. Screen protector. Electrical Specifications: Power Input: AC 100–240V (50–60Hz) Rated Pulse Voltage: 2.5kV Installation: Wall-mounted Operation: 10 push buttons on front panel Protection Class: IP40 Electric Heating Capacity: 1500W Ambient Temperature Range: -10°C to 50°C Temperature Measurement Accuracy: ±2°C Temperature Display Resolution: 0.1°C Collector Temperature Range: -10°C to 220°C Water Tank or Pipe Temperature Range: 0°C to 110°C Input Signals: 1 x PT1000 temperature sensor input 4 x NTC10K B=3950 temperature sensor inputs 1 x rotary vane electronic flowmeter (FRT) Output Signals: 3 x electromagnetic relays, maximum switching current 2A Color: White Material: Plastic Dimensions: 200 x 140 x 43 mm PT1000 Sensor Size: 6 x 50 mm NTC10K Sensor Size: 6 x 50 mm Cable Length: 1.5 meters Package Contents: 1 x Controller 1 x English Manual 1 x PT1000 Sensor 2 x NTC10K Sensors 1 x 10A Power Cord Note: Light and screen differences may cause slight variations in color between the image and actual item. Measurement error allowed is 1–3 cm. Please note: 1. Allow 1–3 mm error due to manual measurement and minor weight variation. 2. Due to lighting and monitor differences, the actual product color may vary slightly from images.