Preparing Summary Paper Protection and Controls for Motor Loads Under Voltage Sag and Recovery John Kueck

The influence of voltage sag and recovery on typical motor protection and controls. This report breaks down each Composite Load Model class into motor types and provides an overview of protection behavior for each type Also, the actual dropout point of much motor control and protective equipment probably depends more on the drop out voltage of relays and contactors, especially the ubiquitous ice cube relay. Summary of Findings

Other Issues to be Summarized Contactors and relays – to be tested soon at SCE, drop out already known. The combined effect with motor protection will be discussed. Discussion of motor speed torque curves, pull up torque and load torque Air conditioner stall as a function of ambient temperature Point on wave – John Undril

Overview and Estimates of Response for the following Protection and Control Types Adjustable Speed Drives Large motors over 250 HP Three phase motors under 250 HP, NEMA Design B Single phase air conditioners Single phase appliances Rooftop air conditioners Chiller motors larger than 250 HP