Table of Contents
- 1 Can we perform regenerative test on dc series machines?
- 2 Why Swinburne’s test is preferred instead of brake test in dc machines?
- 3 Why Swinburne test is conducted only on shunt machine?
- 4 Which of the following is not a disadvantage of a Swinburne’s test?
- 5 Why Swinburne’s test is called as no load test?
- 6 What is the difference between a DC shunt and a series motor?
- 7 Which is not eligible for the Swinburne’s test?
- 8 What does Swinburne mean by no load power input?
- 9 Can a no load test be performed on a DC machine?
Can we perform regenerative test on dc series machines?
Hopkinson’s test of dc machine also known as a Regenerative Test. This test is also one of the efficient ways of determining the losses and efficiency of a dc machine. The test is performed by mechanical coupling of two identical dc machines. In which one machine works as a generator and the other as a motor.
Why Swinburne’s test is preferred instead of brake test in dc machines?
The main advantages of Swinburne’s test are as follows: The power required to test a large machine is small. Thus, this method is an economical and convenient method of testing of DC machines. As the constant loss is known the efficiency can be predetermined at any load.
Why Swinburne test is conducted only on shunt machine?
Swinburne Test of DC Machine Since DC machines are nothing but motors or generators. This test is applicable only for the large shunt DC machines which have constant flux. It is very easy to find the efficiency of the machine in advance. This test is economical because it requires a small input power with no-load.
Why do we conduct brake test on dc series motor?
Since the load is applied directly to the machine shaft, it is a direct method of testing a dc machine. The determination losses and efficiency of a dc machine are done by performing a brake on the shaft through belt and pulley arrangement.
Why Swinburne’s test is called as no-load test?
Since the test is performed without loading the machine it is also known as No-load Test. However, without load, we cannot start a dc series motor. Hence this test is limited for dc shunt and compound machines where flux remains practically constant. The connection diagram for Swinburne’s test is shown above.
Which of the following is not a disadvantage of a Swinburne’s test?
Which of the following is not a disadvantage of a Swinburne’s test? Explanation: For increasing life and durability of a machine we carry out such tests. But stray load losses, steady temperature rise is not determined by this method. Also, results about satisfactory commutation are not given by this method.
Why Swinburne’s test is called as no load test?
What is the difference between a DC shunt and a series motor?
A series motor respond by decreasing its speed with small increase in current for a given load torque. A shunt motor holds its speed nearly constant with large increase in input current for same amount of load torque.
Can we conduct Swinburne’s test on DC series motor?
Swinburne’s test can be carried out on all DC motors. Explanation: Swinburne’s test is a no-load test; thus, it is performed only on shunt and compound motors. DC series motor is not advisable to start at no-load so, this test can’t be performed on series motor.
How is the Swinburne test of a DC machine named?
It is named after Sir James Swinburne. Swinburne’s test is the most commonly used and simplest method of testing of shunt and compound wound DC machines which have constant flux. In this test the efficiency of the machine at any load is pre-determined. We can run the machine as a motor or as a generator.
Which is not eligible for the Swinburne’s test?
Machines having a constant flux are only eligible for Swinburne’s test. For examples – shunt machines and level compound generators. Series machines cannot run on light loads, and the value of speed and flux varies greatly. Thus, the Swinburne’s Test is not applicable for series machines. This is all about Swinburne’s Test.
What does Swinburne mean by no load power input?
The circuit connection for Swinburne’s test is shown in figure below. The speed of the machine is adjusted to the rated speed with the help of the shunt regulator R as shown in figure. Also let, V is the supply voltage. Therefore, No load power input = VI 0 watts. In Swinburne’s test no load power input is only required to supply the losses.
Can a no load test be performed on a DC machine?
1. It is a simple method in which no load dc-machine losses are measured seperately and from this the efficiency at any desired load can be predetermined in advance. 2. It is a no load test and therefore cannot be performed on a dc series motor.