If all equipment is in automatic mode, the water treatment plant starts up in response to a PLANT START signal generated by a low level (LE/LIT-400-1) in the clearwell. The PLANT START signal is sent to the raw water pumps and to the various treatment processes.
The plant will shut down in automatic mode when the PLANT STOP signal generated by a high level in the clearwell. RTU-300 can send an EMERGENCY SHUT DOWN signal resulting from a high turbidity detection (AE/AIT-300-1-1, 2, 3, 4) in the filter effluent. If the PLANT STOP signal is generated, all major plant equipment will be shut off until the PLANT START signal is generated.