MGVCL Exam Paper (30-07-2021 Shift 3)
Which of the following statements are correct? (i) Advanced metering infrastructure (AMI) is typically more automated and allows real- time, on-demand interrogations with metering endpoints. (ii) An Automated Meter Reading (AMR) device only communicates from the customer to the energy supplier. (iii) AMR meters only provide kWh information and possible peak kW demand for the month.
Advanced metering infrastructure (AMI) is an integrated system of smart meters, communications networks, and data management systems that enables two-way communication between utilities and customers. The goal of an AMI is to: Provides utility companies with real-time data about power consumption and allow customers to make informed choices about energy usage based on the price at the time of use.
Symmetrical breaking current is the moment when fault occurs maximum fault current is observed and decays with respect to time. Symmetrical breaking current = RMS value of ac component of short circuit current at the instant of separation of the contacts. Symmetrical breaking capacity is less than asymmetrical breaking capacity.
1.6 inches = 1.6 inches x 1,000 mils per inch = 1,600 mils 0.25 inch = 0.25 inch x 1,000 mils per inch = 250 mils Area = 1,600 x 250 = 400,000 square mils
Type B MCB: Type B devices are generally suitable for domestic applications. They are designed to trip at fault currents of 3 - 5 times rated current.
Type C MCB: Type C devices are the normal choice for commercial and industrial applications These devices are designed to trip at 5 - 10 times rated current
Type D MCB: The Type D devices have more limited applications, normally in industrial use where high inrush currents may be expected. Type D devices are designed to trip at 10 - 20 times.
EXAMIANS