Buyer had only two wires running up to water tank and he wanted to install two overflow alarms, one in his flat and another in security staff cabin. Buyer wished that there should be no overflow under any circumstances. It was a valid concern.
Simple solution was to install two alarms in parallel as in diagram, with each water overflow alarm having its own set of water sensors in tank. This solution required four wires as in diagram. But as said buyer was not willing to add two more wires and wanted us to suggest how to connect two alarms with one sensor set. What to do? After all buyer is king.
To honor buyers wish another way of connecting water tank alarms was needed, which needed only one pair of wires going up to water tank and only one set of water sensors in water tank. The way to do it required that water sensor set is connected in such a way to complete signal path for both the devices. That was done by configuring the water sensors with water overflow alarms to form a series as shown in diagram. One signal wire of each alarm was connected to one water sensor in water tank and other wire was joined with one signal wire of other overflow alarm. With this done both alarms sounded alarm when water sensors get dipped in water and stopped on any one sensor coming out of water. This solution fulfilled buyer need and he happily placed order. We were more than happy, to have lived up to buyers expectations.