What is a useful instrument for checking...

Question 1 / 270705eccefa3bacbc34ba4d47f3d

Question 1 of 270705eccefa3bacbc34ba4d47f3d

What is a useful instrument for checking 3-phase AC motor performance by measuring possible unbalanced currents?

Question 1 of 27070

What is a useful instrument for checking 3-phase AC motor performance by measuring possible unbalanced currents?

🔍 Key Concepts

• 3-phase AC motor currents and how to detect imbalance in each phase • How a clamp-on measuring device works around individual conductors • Difference between instruments that measure current vs those that measure insulation resistance or frequency

💭 Think About

• Ask yourself: which instrument can easily measure the current in each of the three individual phase conductors without breaking the circuit? • Which option is specifically designed to measure current magnitude in a live conductor by encircling it, rather than touching bare metal? • Which instruments in the list are used for other purposes such as checking frequency or insulation resistance, not load current balance?

✅ Before You Answer

• Verify which choice is actually an ammeter-type device intended for current measurements in each phase line. • Eliminate any instruments whose primary function is to measure frequency or insulation resistance instead of load current. • Check which device is commonly used on ships by electricians to quickly compare phase currents under normal running conditions.

Question 1 of 27070

What is a useful instrument for checking 3-phase AC motor performance by measuring possible unbalanced currents?

vibrating-reed frequency meter

hand or battery-operated megger

D'Arsonval iron-vane probe

clamp-on ammeter

Question 1 / 270705eccefa3bacbc34ba4d47f3d

Question 1 of 270705eccefa3bacbc34ba4d47f3d

What is a useful instrument for checking 3-phase AC motor performance by measuring possible unbalanced currents?

Back

Question 1 of 27070

What is a useful instrument for checking 3-phase AC motor performance by measuring possible unbalanced currents?