The Durapulse GS4 series of ac sensorless vector drives includes dynamic braking, PID and removable keypad. The drives are available up to 300 hp in 460-V models and up to 100 hp in 230-V models. All 230-V models can operate in three-phase or single-phase configurations. The drives have a 100-kA short-circuit current rating (SCCR), a 50 °C operating temperature rating and built-in safe torque off (STO). Built-in I/O includes eight dc digital inputs; two dc digital outputs (up to 48 V); and five analog channels (three inputs and two outputs) configurable for voltage, current or potentiometer (input).