Electronic Systems Design”sModel 250C reverse osmosis system controller is a low-cost, reliabledevice designed for manufacturers of industrial and commercial waterpurification systems. The controller maintains water tank level, has alockout input for pre-treatment regeneration, low pressure shutdown,etc.  It controls inlet and flush valves rated at 24VAC, 5W. The pump output is an isolated power relay rated at 240VAC, 2HP(20Amp).  The controller also incorporates several flush cycles tohelp increase membrane life.  The primary power is 120/240VAC,50/60 Hz, and the NEMA 4 enclosure is 6″ x 6″ x 4″.