TCF-F Series

Two wires from the relay are connected to the FLS or CLS leakage sensor which is in series with the pump over temperature switch.  A low-voltage DC signal is applied to measure the current flow through the sensor and over temperature switch. The sensor controls the current in this circuit. These products have isolated output contact relays, one for over temperature and one for seal leakage.

With input voltage applied, normal temperature condition (thermal switch closed) and no seal leakage, the sensor current will be in the normal range. The over temperature relay is energized and the seal leak relay is de-energized. Both LEDs are Green, indicating normal conditions and input voltage applied. 

When the motor temperature rises and the N.C. thermal switch opens, the sensor current drops to zero. The over 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 over temperature condition is cleared, the unit will reset based on the setting of the Over Temp switch.  In the AUTO mode, the unit will reset automatically.  In the MANUAL mode, the Over Temp Reset button must be pushed to clear the alarm and reset the relay.

In a seal leakage condition, contaminating fluid enters the pump motor cavity. The sensor lowers its resistance, increasing the sensor circuit current above the trip point.  The seal leakage output relay energizes and closes a contact, which can be used to give an alarm indication of a leaking seal. The LEAK LED turns Red.

Cleared Fault Condition
If either an Over Temp fault condition when the Over Temp switch is set to AUTO or a Seal Leakage fault has been automatically cleared, a cleared fault indication is displayed by flashing the corresponding Red TEMP LED or Red SEAL LED.  The flashing indication may be manually reset by pressing the Over Temp Reset button. Note: if either fault still exists when the Over Temp Reset button is depressed, it is ignored. 

Shorted Sensor
If the sensor wires are shorted, the unit will display a Shorted Sensor condition by alternately flashing the Red SEAL LED and the Red TEMP LED.  If the short is removed, the fault will automatically reset within 30 seconds.