TCF2A

Description Of Function A normally closed thermal switch in the windings of the pump motor is connected to the TEMP input to monitor for overheating of the pump. A low-voltage DC signal is applied to monitor the thermal switch. The pump seal leakage sensor(probes) are connected to the LEAK input to monitor for seal leakage using a low-voltage DC signal. Isolated output contact relays are provided, one for over temperature and one for seal leakage. The over temperature trip point is fixed at 5K ohms. Adjustable seal leakage sensitivity range is 4.7K-100K ohms. With input voltage applied, normal temperature condition (thermal switch closed) and seal leakage above the sensitivity set-point, 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 motor temperature rises and the N.C. thermal switch opens, the over temperature relay is de-energized opening the contact that had been closed 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 AUTO-MANUAL RESET 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. (Note: If fault still exists when the Over Temp Reset button is depressed, it will not reset.) If the shaft seals start to leak, contaminating fluid enters the pump motor cavity. This lowers the resistance of the lubricant inside the pump. When the resistance drops below the user-adjustable sensitivity set-point of the relay, the 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. If the seal leak condition is cleared, the unit will reset automatically. If either a TEMP or SEAL leak alarm has been automatically cleared, a cleared fault indication is displayed by flashing the corresponding Red TEMP LED or Red SEAL LED after the alarm state has been cleared. The flashing indication may be reset by pressing the Over Temp Reset button.