Coursera Quiz

Accordingly, the self-mixing drum will be made much larger, but the rest of themixer will look the same. What will you need to change about the motor you specify now? The power, starting torque amd operating torque will need to be increased. 

Which of the items below about Star/Delta AC motor starter systems is true? Select all that apply. With the Star connection at V3 times the nominal input voltage, the current is divided by v3 again, for a total of 3 The Star and Delta contactors are electrically interlocked The current through the stator windings is broken when the Star contactor opens, and it is restored when the Delta contactor closes There is a 30 -50 milliseconds break in supply after the Star contactor opens and the Delta contactor closes.

Which of these statements about a manual starting system for a full Voltage Reversing 3-phase motor is true? The power, starting torque and operating torque will need to be increased

You purchase a motor in Germany designed to run at 415 Volts, 50 Hz. It has 75 kW output power, runs at 2978 RPM and has 240 N-m of rated torque. You ship it Canada and run it at 480 Volts, 60 Hz. What will be the new speed in RPM? 3573

Why are the Star and Delta contactors electrically interlocked? This prevents short-circuiting between phases, as the Star and Delta contactors cannot close simultaneously

Suppose you need to buy a motor for a chemical operation that makes propane 500 hours per year. The rest of the time the motor is not used. You need an intrinsically safe motor. The ambient temperature does not exceed 40° C. According to the North American ratings, what explosion proof rating of motor should you purchase? Class 1, Zone 1, AEx, i, II, T6

You have an application where the motor will be exposed to dirt and dampness, but not in an environment where flammable dust or gases are located. You have no concerns about the motor overheating. What type of motor enclosure do you need? TENV

Motors and Motor Circuits Week 2 What is the rated power output in kW of a 8-pole motor designed to an IEC 180L motor frame? (Type in an integer.) 11

Motors and Motor Circuits Week 2 You purchase a motor in Germany designed to run at 415 Volts, 50 Hz. It has 75 kW output power, runs at 2978 RPM and has 240 N-m of rated torque. You ship it Canada and run it at 480 Volts, 60 Hz. What will be the new output power in kW? (Type in an a one-decimal number 86.7

Motors and Motor Circuits Week 2 In both the North American and International motor efficiency standards, how does the required efficiency vary as a function of the motor power? The efficiency increases as the power increases.