Use this controller to controller the pumping between two systems based upon there temperatures and the difference in temperatures. This is most commonly used for solar power water heater and pool/spa heating. It has three temperature sensors and two relays to control the pump and the optional additional heater. It has a vast feature set which it allows it to be customised to your personal application, they include
• Automatically program your backup heater (e.g. electric or gas) to come on if you main heating source is not hot enough. This can also be set to happen within a specified time frame.
• Optional 3rd temperature sensor to measure the temperature at an additional part of your system for finer control.
• Switch pump on and off, on specified minimum and maximum temperature differences.
• Emergency switch off, for when temperature of the collector gets too high, adjustable range 120 – 200C.
• Maximum collector temperature, activate this to limit the maximum temperature your collector reaches, adjustable range 110 – 190C. This can be used as a means of self-protection against overheating or gassing the collector.
• Minimum collector temperature, to keep your collector from becoming too cool, a mode can be activated, using warmer fluid from your tank to keep the collector above the minimum set temperature, adjustable range 0 – 100C
• Frost Protection setting. This can automatically start your heater to stop the fluid freezing. Set the minimum temperature point you wish to keep above adjustable range -10 – 10C .
• Maximum tank setting 2-95C, using the 3rd temperature sensor (optional) you can monitor a separate location, and if that location goes above the set temperature the pump will stop, until this temperature is 2 C lower than the set point.
• Tank re-cool, if tank is over the set temperature and the collector is at least 5C cooler, this mode allows the collector to cool the tank.
• Supplementary heating from a second heater can be configured to top up the heating from the collector. If this mode is activated and if the measured temperature is 2C less than the set temperature, the supplementary heating will be activated to bring the system up to the set temperature.
• Size: 178mm×120mm×43mm
• Power consumption: < 3W
• Accuracy of temperature measuring: ±2centigrade
• Range of collector temperature measuring: -10～220C
• Range of tank temperature measuring: 0～110C
• Suitable pump power: 600W
• Temperature Sensors: 1 x Pt1000 for collector(1.5m long) 2 x NTC10K for tank (2.9m long)
• Relays: 1 for circulation pumps 1 for supplementary heater Both relays are 3.5A
• Ambient temperature: -10～50C
• Settings can protected by pincode.
• View all three temperature sensor measurements on screen.
• Digital Clock on screen
• Preserves settings on power loss
• LCD backlight (active when last key press is less than 3 minutes ago)
manual is here http://waveinverter.co.nz/download/SR208C-EN.pdf
Comes with 12 month RTB Warranty