Trouble shooting

Question 1

When ever equipment or circuits are not working, first check for _____________.

Answer 1

incoming power.

Question 2

The two fundamental steps in troubleshooting are:

Answer 2

1. Visual inspection and testing without tools
2. Analyzing with diagrams and meter measurements

Question 3

Visual inspection sometimes quickly locates a fault or identifies situations requiring maintenance. For example you can see:

Answer 3

-A tripped indicator on a circuit breaker, switch or overload relay.
-Burnt or heat-discoloured components.
-Loose wires in terminal block.
-Mechanical parts that bind together or cause excessive friction.

Question 4

To check incoming power for motor controls, you do three sets of measurements:

Answer 4

1. At the line terminals
2. On the line side of the disconnect
3. Across the fuses

Question 5

The following method for measuring the voltage from the line side of one fuse to the load side of the remaining two fuses is called a ________.

Answer 5

Criss-cross method

Question 6

Three-phase motor may continue to run when only one fuse is blown is called a __________

Answer 6

Single phasing

Question 7

Voltage can be measured on the load side of a blown fuse only with the power ON. True or False?

Answer 7

True

Question 8

What are the cause of contacts chattering?

Answer 8

-Broken shading coil
-low voltage
-poor contact in control circuit