This may seem like a simple application to solve, but enough time, I saw some novice programmers to take the lazy approach when starting a bank of three phase motors. A motor is an inductive load big enough, and inductive loads we get burst.
Say we have 10 three-phase motors with all HP. For our example, we assume our input voltage is 460 volts 3 phases.
Each of our drivers have the full load current, or (FLA) of approximately 1.0 GPA each, so about 10 amps all together when all the engines running. Current of the motor to start right when you first saw the engine or motor powered reel start to start the engine. Typical starting current motors can be as high as 300% or more of the coast of FLA. This means that your engine only HP could generate a train of 3 amperes when the engine starts for the first time. Now back to the lazy programmer. If you start to roll all your starter in a parallel branch of both your logic, you can guess what would later call on your electrical system to 10 motors? You guessed it, if you said 30 amps. (more…)
Tags: 3 Phase Motor, 3 Phase Motor Startup, PLC ladder Motor, PLC programming, PLC training3 Phase Motor, 3 Phase Motor Startup, PLC ladder Motor, PLC programming, PLC trainingShare This