Chapter 4: Electrical Measurement & Testing Equipment

Question 1

Voltage tester

Answer 1

Indicates whether voltage is present in a circuit

Question 2

Digital voltage tester

Answer 2

Used indicator lights or a digital readout to report the amount of voltage present. Draws little current from the circuit.

Question 3

Solenoid voltage tester

Answer 3

Uses a higher amount of current to activate the tester’s solenoid, which indicates the presence of voltage.

Question 4

What are two small and inexpensive voltage testers?

Answer 4

Circuit tester and noncontact voltage tester

Question 5

Circuit tester

Answer 5

Has two interchangeable probes and a small light indicating voltage.

Question 6

Noncontact voltage tester

Answer 6

Can detect voltage through wire insulation or by having its tip pushed partway into a receptacle slot

Question 7

Receptacle tester

Answer 7

Plugs into a standard-voltage (120V) receptacle. Tells you whether the receptacle is wired properly and is grounded or if it has a wiring problem.

Question 8

Some receptacle testers can be used with ________ to identify the receptacle’s circuit.

Answer 8

Wireless circuit breaker tester units.

Question 9

VOM

Answer 9

Volt-ohm-milliammeter

Question 10

Multimeter

Answer 10

Tests for multiple electrical properties, including voltage, current, resistance, and continuity.

Question 11

Before using a multimeter you must know the _____ and the approximate ____ and _____ of the circuit or device.

Answer 11

Type of current (ac or dc); voltage; current

Question 12

Using a handheld meter in a _________ may damage the meter and possibly cause an injury.

Answer 12

High-voltage circuit

Question 13

Clamp meter

Answer 13

Tests current through insulation by hooking around the wire or cable. May be used in a residential setting to test service wires.

Question 14

Maximum testing capability of voltage testers and multimeters

Answer 14

240 V and 10 A

Question 15

Maximum testing capability for clamp meters

Answer 15

1,000 A and 1,000+ V

Question 16

Insulation tester

Answer 16

Tests the resistance of insulation: whether it is good enough to safely handle the current flowing through the wiring.

Question 17

How does an insulation tester work?

Answer 17

It applies a preset level of dc voltage and a relatively small amount of current through wiring and checks for losses that can indicate leakage through the insulation.

Question 18

What are three other names for an insulation tester?

Answer 18

Insulation resistance tester; megohmmeter; meggie.

Question 19

Earth ground tester

Answer 19

Checks the earth’s resistance to dissipating energy around a ground system.

Question 20

Soil and its contents- including rock, moisture, and impurities- can vary widely in ________________.

Answer 20

How well it accepts electrical energy.

Question 21

Soil with ________ provides a less effective ground than soil with ________.

Answer 21

Higher resistance; low resistance.

Question 22

The resistance of soil can change with ____ and _______ changes.

Answer 22

Time; temperature.

Question 23

The testing method most commonly used for a single residential ground rod is called ________. This tests a ground rod’s ability to __________.

Answer 23

Fall-of-potential; dissipate energy at its current location.

Question 24

During new construction, an electrician may conduct a _________ test to determine a suitable location for installing a new ground rod.

Answer 24

Soil resistivity

Question 25

Phase and motor rotation testers

Answer 25

Used by maintenance electricians to determine motor rotation direction and to check the phase sequence of a motor’s power supply wires.

Question 26

A tester’s _________ must be higher than those of any equipment the tester will be used on.

Answer 26

Voltage and amperage ratings

Question 27

What symbol indicates a tool is double-insulated?

Answer 27

A small square inside of a larger square

Question 28

Proper polarity is important when testing ______ and _______ but not ______ or ________.

Answer 28

Voltage and current; continuity or resistance

Question 29

The red probe on a tester is ______ and connects to the _______ wire

Answer 29

Positive; hot

Question 30

The black probe on a tester is _______ and connects to the ______ wire.

Answer 30

Negative; neutral

Question 31

What readings might you get from a receptacle tester indicating there’s a problem with the receptacle?

Answer 31

Open ground; open neutral; reverse polarity; open hot