Series DLD is used to monitor the shaft seal of two submersible pumps to detect a leak before pump failure. The dual-channel relay detects a leak by sensing the status of a float or conductivity switch installed in the seal cavity. When the resistance drops below the set sensitivity, the output relay energizes and the LED indicator illuminates. The device offers normally open relay contacts to energize an alarm and de-energize the pump in the event of a leak. When the seal failure condition clears, the relay automatically resets.
Dwyer Instruments Inc., (800) 872-9141