The new SCU 345 solar system control from Viessmann has preconfigured layouts for one-, two- or three-load systems, four relay outputs and adjustable delta-T and time-controlled thermostat functions, offering limitless configuration possibilities for multi-load and commercial solar systems. It also incorporates standard SCU series control features including variable-speed pump control, east-west collector array logic, collector glycol cooling function, nighttime tank cooling, heat rejection loop control, energy metering and compatibility with VBus