The panel should show all indicators off until the control circuit switch is switched to the automatic (AUT) position, at which point the yellow indicator lights up.

If the start/stop command (P11-P12) closes, the pump starts (green indicator and LEDs “PWR”, “COM” and “OUT” of the PRObomba relay), switching off if the start/stop command reopens.

If during operation the PRObomba relay detects consumption higher than the maximum parameter or lower than the minimum for more than 4 Within seconds, the pump shuts down, and the cause of the fault is indicated on the relay display: “EIH” – overcurrent error or “EIL” – undercurrent error. If the detected anomaly is due to undercurrent, automatic reset will be attempted 3 times at 5-minute intervals (factory preset value, but user-changeable), with the last reset attempt occurring after 99 minutes, after which the relay will permanently shut down. If the detected anomaly is due to overcurrent, the pump shuts down and the relay will not attempt any reset. Manual reset can be performed using the reset key “RST” on the Probomba Relay or via the control circuit switch, simply by switching it off and on again. Whenever during operation the supply voltage is found to be higher than the maximum parameter or lower than the minimum (factory preset values) for more than 4 seconds, the PRObomba Relay display indicates every 4 seconds (“EUH” – overvoltage error or “EUL” – undervoltage error). Opening the safety command (C11-C12) switches off the pump, regardless of the start/stop command indications. If the safety control is not to be used, it must be closed via a "shunt".