Q27. How can you determine if a relay is operating (changing from one position to the other)?
Q28. What items should be checked on a relay that is not operating properly?
Q29. What is used to clean the contacts of a relay?
Q30. What tool is used to set contact clearances on a relay?
This chapter has provided you with basic information on circuit control devices. The following is a
summary of the main points in this chapter.
CIRCUIT CONTROL DEVICES are used to apply or remove power and to select a function or
circuit within a device.
A SWITCH is one type of circuit control device. Switches are classified in many different ways.
A MANUAL SWITCH must be tuned ON or OFF by a person. An AUTOMATIC SWITCH will
turn a circuit ON or OFF without the action of a person by using mechanical or electrical devices.
MULTICONTACT SWITCHES make possible the control of more than one circuit or the
selection of one of several possible circuits with a single switch.