Wet marine engine exhaust systems are designed to resist temperatures of not more than 120°C. The exhaust gases, however, may reach more than 500°C. To cool the gases, the exhaust cooling system depends on a free flow of cooling water from the engine. This flow can drastically decrease, due to a lot of reasons such as a plastic bag or seaweed being sucked into the seacock under the keel, or by a problem with the water pump. The exhaust temperature will rise immediately to around 450°C, the exhaust will overheat and may be seriously damaged. In all these situations "HYDROALARM" exhaust temperature alarm system will warn you before serious damage occurs.

How "HYDROALARM" system works

"HYDROALARM" alarm system works both with 12 or 24 volt supply. It has three main components:

1 - A temperature sensor which continuously takes the exhaust temperature. It must be placed in the inlet pipe of that silencer which must be equipped with "HYDROALARM" exhaust temperature alarm system. This system accepts up to three sensors, covering twin engined craft with one generator. If a larger number of sensors needs to be placed on the exhaust system than those "HYDROALARM" doesn't accept, special pipes fitted with a threaded thimble, eventually to fit another temperature sensor, are available.

2 - An helm display. This neat display fits near the helm and must be continuously taken under control. This unit has a ready green light, with three warning red lights for each engine monitored and a small buzzer. The display self-tests when the engine is turned on, flashing the green lights. If one sensor overheats the relevant red light will flash and the buzzer will sound. A tiny button allows you to shut down the buzzer.

3 - The junction box. This compact "HYDROALARM" unit fits on a bulkhead in the engine compartment. Wires from the sensors and the helm display connect to it. It connects also to the power supply (which must be live only when the ignition is turned on). A fuse is fitted for protection so that the system can be disarmed.

The buzzer incorporated in the helm display is siutable only to alert someone at the helm site. An optional 120 dB siren can be fitted to give a really loud alarm, or if somebody wants to place the helm display out of sight.

By consequence of being SILENCERMARINE "HYDROALARM" exhaust temperature alarm system provided with sensors capable of taking the exhaust temperature in direct contact with gases, really makes this instrument one of the most effective system on the market.