Seal Leak Temperature Relay. Two wires are connected to a resistive-sensing probe and common in the seal cavity to monitor for seal leakage. Two additional wires are connected to a N.C. thermal switch in the windings of the pump motor to monitor for overheating. The product has isolated output contact relays, one for seal leak and one for temperature. The temperature set-point will be fixed at 5K ohms. Two adjustable seal leak sensitivity ranges are available: 4.7K-100K ohms and 1K-250K ohms. With input voltage applied, normal temperature condition (thermal switch closed) and no seal leak, the isolated temperature relay is energized and the isolated seal leak relay is de-energized. Both LED's are Green. When the motor temperature rises and the N.C. thermal switch opens, the temperature relay is de-energized, opening a contact that had been closed and turning off the pump contactor. The TEMP LED turns Red. If the seal starts to leak, contaminating fluid enters the seal cavity. This lowers the resistance between the internal probe and the common connection. When the resistance drops below the user-adjustable sensitivity set-point of the relay, the seal leak relay energizes and closes a contact, which can be used to give an alarm indication of a leaking seal. The LEAK LED turns Red. These products will automatically reset when the fault condition clears.
