Leak/overtemperature detection relay

The Series LDT relay is used to monitor the shaft seal and the stator temperature of a submersible pump to detect a leak or overtemperature before pump failure.

A leak is detected by sensing the status of a float or conductivity switch installed in the seal cavity. When this resistance drops below the set sensitivity, the output relay energises and the LED indicator illuminates. When the seal failure condition clears, the relay automatically resets. A normally-closed temperature switch mounted on the stator detects overtemperature. The temperature safety feature incorporates a bi-stable relay that retains its position during power loss and latches on until the remote reset button is pressed.

The LDT has adjustable leak sensitivity from 1 k to 35 kΩ. Installation is made simple with a surface-mount configuration.