Sump Sensors (DDS, DTS, DMS, ULS)

Most leaks on a forecourt show up first as liquid in a sump: under a dispenser, or in the containment chamber over the submersible pump. Franklin offers four sump sensors, and the choice depends on whether the site must know what the liquid is. Rainwater in a sump is a maintenance job, while fuel there is a leak, so discriminating sensors tell the two apart.

The DDS (dispenser sump) and DTS (turbine sump) are the same discriminating design placed in different sumps. Magnetic float switches detect liquid at two levels, starting 1½" (38 mm) from the base, and a polymer strip along the body reacts to hydrocarbons. They report liquid in sump, hydrocarbon detected, sump full and sensor fault. The FMP-DDS-UD version also has a spare input for a 2-wire simple apparatus, which the EVO™ monitors as well.

The DMS uses magnetostrictive floats instead, giving a measured water level with programmable warning and alarm points plus a product alarm. Its tamper feature alarms if the sensor is moved from where it was installed. It comes in TSP-DMS-12 (monitors 12" of liquid) and TSP-DMS-24 (24"). For sites that only need to know that liquid is present, the low-cost ULS float switch hangs from standard ½" NPT electrical fittings. Two ULS sensors can share one EVO™ 400 or EVO™ ONE input.

Apex supplies and installs Franklin sump sensors in Lebanon and matches each model to the console and sump type.