The backwash pumps and air blower do not have E-Stop buttons but the HAND / OFF / AUTO switches at the MCC, PCS, and RTU may be used to shut down a unit in an emergency situation. In addition, the filter FCVs can be closed with the OPEN / CLOSE / AUTO switches on the PCS or RTU.
If utility power is lost, the PCS will coordinate restart of the backwash pumps and air blower (if in backwash mode) when power is restored or switched to standby generator power. Startups of plant equipment are staggered to avoid high amperage draws to the generator. All equipment will restart with the settings at the time of power loss.
If power is lost to the turbidmeters or filter headloss gauges, the filter FCVs will remain in the position at the time of the power loss.