Model 520CS is a fully programmable, microprocessor-based, current sensing device designed to monitor three phase pumps. Unlike the Model 520CP which is designed to work with motors that have ramp up times of 4 seconds or less, the Model 520CS has a programmable motor acceleration parameter that can be set from 0-50 seconds. Three external current transformers must be utilized in conjunction with the Model 520CS. The following 9 parameters can be set and viewed from the three digit alphanumeric LED: over current trip point, under current trip point, current unbalance trip point, trip delay, rapid cycle timer (RD1), overload restart delay (RD2), under load restart delay (RD3), number of starts after a fault, and motor acceleration time. Last fault diagnostics is also viewable. When a harmful condition is detected, the MotorSaver's output relay is deactivated after the specified trip delay. The output relay reactivates after the appropriate RD2 or RD3 timer has expired. Over current, under current, and current unbalance are ignored during the motor acceleration period, however, if the motor is started on a single phase or a reverse phase condition. The Model 520CS deactivates its output relay in 0.5 seconds.

The Model 520CS can be ordered with an output jack so that the unit can utilize a Model 520RD front panel remote display.