Performance Analysis of Increased Safety HT Induction Motor with Higher Stator Coil Pitch for Classified Hazardous Area

Abstract

The increased safety (Ex e) high tension (HT) motors are widely used in the petroleum industries and area where explosive atmosphere is present. The time t_E and I_A/I_N ratio value is very important for Ex e motor. The time t_E of rotor and or stator winding, I_A/I_N ratio and temperature rise can be affected by increasing the stator coil pitch. The coil pitch of stator were increased for three different ratings of three phase HT Ex e induction motors and redesigned for analyzing the temperature rise, t_E and performance. The relevant tests were performed and performance characteristic of motor was compared with normal design motor. The Ex e motors mentioned in this paper had been manufactured by Bharat Heavy Electricals Ltd. (BHEL), Bhopal, India during the project as per the design and guidance of main author as project leader. It is anticipated that the research work presented in this paper will be of immense benefit to Ex e HT motor designers.