The C100A is a variable-speed controller that features both manual speed adjustment via a front-panel-mounted rotary dial and electronic speed control via a 4–20-mA signal from an external source (sensor, flowmeter, analyzer, process controller, etc). Additional features include iR compensation, a current-limiting circuit, and minimum and maximum speed adjustment, which are all factory-preset to meet specific application parameters. It also incorporates transient-voltage protection and an AC fuse. The C100A is appropriate for controlling the firm’s Chloritrol valveless hypochlorite injection system and CTS chemical treatment system, both of which provide maintenance-free fluid control for the water and wastewater treatment industries. It is especially well-suited for applications that operate continuously in remote locations. The C100A retains settings and resumes operation following a power interruption or failure without the need for an operator to manually restart it. The electronics are housed in a space-saving NEMA 4/12 enclosure suitable for wall mounting.