PV Direct Ready Cylinders
Many brands and styles of storage water heaters can be electrically configured to be connected with the Solatherm control system. The cylinders are identified as PV DIRECT >> Ready cylinders are pre-configured in this manner.
The cylinder has a dedicated DC electrical circuit. In this circuit a DC approved over temperature cut out (PV-OTC) is installed. In addition, the cylinder has a specific, long life element designed for DC to match the PV array.
The cylinder must have twin elements or have an inline instantaneous gas booster to meet Australian solar hot water storage cylinder requirements.
Electrically boosted cylinders have an independent AC Mains electrical circuit that is connected to the boost element in the same way a conventional electric hot water storage cylinder is connected. This provides a top up of hot water during extended periods of low solar input.
The boost capacity has been set to meet the minimum volume requirements for off peak boosting in all states. Generally the independent AC boost element is connected to an off peak (controlled load) power supply. If only peak is available it is recommended to install a din rail timer and set a heating period during the early evening and/or early morning depending on the household demand. If the water in the storage vessel is higher than the 600C thermostat setting the unit will not draw any power as there is no need. If the water is below 600C during the set periods the boost element will top up the temperature to ensure hot water is available. The boost element heats approximately 125L of water. Connection via a timer will maximise solar gain during the day, minimise energy consumption and allow for ease of use. High usage households may require extended boost periods or continuous mains connection to meet high demand.