MGVCL Exam Paper (30-07-2021 Shift 1)
A THHN conductor will have 75°C termination on one end and a 60/75°C termination on the other, which ampacity column will be used?
Conductor with 75 °C temperature rating must have ampacity from the 60°C column or the 75°C column. It is permissible to use the 75°C rating if the installed conductor is rated at least 75 °C. Because all of the connection points in this example have at least a 75°C rating, the conductor’s ampacity can be based on the 75°C column
Class B trip curve: The MCB with class B trip characteristics trips instantaneously when the current flowing through it reaches between 3 to 5 times rated current. These MCBs are suitable for cable protection. Hence, For 16 A current Type B MCB disconnect fault at 3*16 = 48 A to 5*16 = 80 A.
Bus Type - Known Parameter - Unknown Parameter Load Bus -P, Q - V, phase angle Generator Bus - P, V (magnitude) - Q, Voltage phase angle Slack Bus Voltage - magnitude and phase angle - P, Q
EXAMIANS