This controller is normally used in closed loop process control applications where an error signal is provided by a set
point type process control instrument. Potentiometer adjustments are provided for zero adjust (set point), ratio control
(proportional band), and dead band. All three adjustments are located behind the control box cover (see Figure 5).
Model AMI and AMI-MA Control Units (Figures 10 and 11) are combination automatic-manual controllers; both have
the RMI circuitry for remote manual control and percent capacity meter indication. The model AMI incorporates the
PRRA automatic control circuitry (slide wire input), and the model AMI-MA has the PRRA-MA circuitry (DC milliamp
input). These units use a toggle switch for selection of automatic or manual mode. The actuator unit furnished with
these controllers has a dual potentiometer arrangement. One potentiometer provides the position feedback signal to the
controller, and the potentiometer is used for the percent capacity meter on the panel.
Figure 5. Signal Input vs. Pump Capacity