The main disadvantage of the Ward-Leonard control method is high initial cost, high maintenance cost, low efficiency at light loads.
Description : Write one advantage and one disadvantage each for spring control method and gravity control method.
Answer : Advantages of Spring Control Method: 1) The spring-controlled meters may be used in any position. 2) In some instruments, springs can be used as current leads. 3) As springs are light in weight ... only. 2) Scale is non-uniform. 3) Control weights add to the weight of instrument.
Answer : In Ward-Leonard control the lower limit of speed is imposed by residual magnetism of the generator.
Answer : Ward-Leonard control is basically a voltage control method.
Answer : Speed control by Ward Leonard method gives uniform speed variation in both directions.
Description : List one advantage and one disadvantage of one wattmeter method.
Answer : Advantages: 1) Only one wattmeter is used. 2) Less number of connections. 3) Cost required is less. Disadvantages: 1) Used only for 3- Φ balanced load and not for ... be accessible for connecting the Pressure coil. 3) Delta connection must be opened to connect current coil.