Circuit breakers are fitted to protect the heavy power circuits against short circuit. Each circuit breaker not only acts as the main switch, but also, in the event of a water temperature rise within the heater vessel being sufficient to operate the safety thermostat, a safety trip is triggered within the circuit breaker. This safety trip will totally isolated the heater at its point of supply. Operation of the safety thermostat switches off the working contactors before energising the in-built shunt trip of the circuit breaker, the heater will not operate again until both the safety thermostat and the circuit breaker are manually reset, giving the ZENITH heater a unique double protection against overheating and damage to the elements. 

 

ZENITH heaters are fitted with a thermometer to indicate the outlet water temperature. By using the thermostat to monitor the water temperature rise, it enables the installation engineer to adjust the flow rates within the heaters; this is particularly useful if the heater is installed with a by-pass, branched off a much larger flow pipe, used in multiples or is operated in parallel with an alternative means of heating. 

 

Additionally a 2-step temperature controller overrides the time delay in the event of a rapid temperature rise. To cope with the increased power, four safety valves are fitted. 

Cast in BS-EN-1561-1997-ENGJL-200 iron, with a heavy fusion bonded epoxy coating impervious to salt water or chemically treated pool water. The heater vessel is constructed in accordance with British Patent GB 2 092 282 A. The vessel has a design pressure of 35psi (2.46kg/cm2) and is fitted with 3/4" pressure relief valve(s) set to operate at the maximum normal working pressure of 30psi (2.1kg/cm2) giving protection to both the heater and the installation as a whole against over pressure. A 1/2" drain valve at the lowest point allows the heater to be left empty in winter. Water flow connections consist of easily removable uPVC stub flanges into which the water supply pipes may be fitted using suitable adhesive. Standard flow direction is from left to right. The direction may be reversed quite simply on site following the installation instructions.