Final Topics

Question 1

Which of the following should be included in a home inspection? (Note - you may choose more than one answer.)

a) low voltage systems
b) operation of all smoke detectors
c) polarity of some receptacles
d) grounding of all exterior outlets
e) operation of all GFCIs

Answer 1

c) polarity of some receptacles

e) operation of all GFCIs

Question 2

List four different branch wire materials you might see.

Answer 2

1. Copper
2. Aluminum
3. Copper clad aluminum
4. Solder-dipped copper

Question 3

Describe three different cable types you might see.

Answer 3

1. NM, Romex, Loomex
2. UF or NMWU
3. BX (AC-90), armored cable
4. Knob-and-tube

Question 4

What is the difference between insulation and sheathing?

Answer 4

Insulation is around the individual wires, and sheathing forms the cables by wrapping around the insulated wires.

Question 5

Which of the following wires are stranded?

a) #14
b) #12
c) #10
d) #8
e) #6

Answer 5

d) #8
e) #6

Question 6

The most common wire size for branch household circuits is what gauge?

Answer 6

14

Question 7

What is an overloaded circuit?

Answer 7

An overloaded circuit has a large number of outlets, switches or appliances. Under normal circumstances, the current may exceed the circuit ampacity and rating of the fuse or breaker.

Question 8

How are extension cords different from permanent wiring?

Answer 8

Extension cords are flexible and stranded. They have lighter sheathing that is not intended to be stapled or secured in place permanently. The gauge of extension cords, is typically 16 or 18 gauge, smaller than permanent wiring.

Question 9

When a wire leaves a box, how far should it run before it is supported or secured?

Answer 9

Twelve inches

Question 10

Running along the length of the wire, how far apart should the supports be?

Answer 10

Four and a half to five feet

Question 11

What are the issues on running wire through steel studs?

Answer 11

Wire may be damaged by sharp edges of steel studs. Wires passing through holes should be protected with grommets for example. Wires running parallel to studs should stand off the studs.

Question 12

Give five examples of poor locations for wiring.

Answer 12

1. Exposed to damage, on wall surfaces for example
2. Under carpets
3. Close to the edge of studs or joists
4. In ductwork
5. Against pipes, ducts, exhaust flues vents, chimneys or other heat sources

Question 13

List 17 common branch circuit wire problems.

Answer 13

1. Damaged
2. Not well secured
3. Loose connections
4. Open splices
5. Wires too close to ducts, pipes, vents, chimneys, and flues
6. Wires too close to the edge of studs or joists
7. Wires run through steel studs without protection
8. Exposed wires on walls or ceilings
9. Exposed wires in attics
10. Wire run under carpets
11. Cable used outdoors
12. Buried cable not rated for buried use
13. Overhead wires not stranded
14. Household wire used as extension cords
15. Undersized wire
16. Improper color coding
17. Abandoned wire

Question 14

Give four examples of damaged wire.

Answer 14

1. Cut or pinched
2. Chewed on by animals
3. Burned wire
4. Wire with brittle or cracked insulation

Question 15

List three methods for securing wire ends.

Answer 15

1. Terminal screws
2. Push-in connectors
3. Solderless connectors

Question 16

What is meant by ‘open splice’?

Answer 16

An open splice is a connection that is not made inside a junction box.

Question 17

Wire should be how far away from ducts and pipes?

Answer 17

One inch

Question 18

Wire should be how far away from the edge of studs.

Answer 18

One and a quarter inches

Question 19

A grommet is:

Answer 19

A grommet is a fitting that protects cable from the sharp edges of steel
studs.

Question 20

Wires should not be run on wall surfaces without –

Answer 20

Mechanical protection

Question 21

What is the problem with running wire across the top of the attic ceiling joists?

Answer 21

Because they are not visible and may be stepped on

Question 22

Abandoned wire should be –

Answer 22

Removed

Question 23

Describe how knob-and-tube wiring is visibly different from modern cable.

Answer 23

The black and white wires are separate, so the circuit wires usually run in
pairs. There are ceramic tubes protecting the wires where they pass through joists or studs. There are ceramic knobs where the wires change direction.

Question 24

Does knob-and-tube wiring have a ground wire associated with it?

Answer 24

No

Question 25

List four common problems with knob-and-tube wiring.

Answer 25

1. Connections not in boxes
2. Brittle wire, insulation or sheathing
3. Wire buried in insulation
4. Fused neutrals

Question 26

List three common problems found with aluminum wiring.

Answer 26

1. Connectors not compatible with aluminum
2. No anti-oxidant grease on stranded wires
3. Overheating

Question 27

How would you identify aluminum wiring?

Answer 27

The conductor itself is silver colored. The sheathing usually has the word
ALUMINUM, ALUM or AL.

Question 28

When was aluminum wiring used?

Answer 28

Aluminum wiring was used from the mid 1960s to the late 1970s.

Question 29

What caused the problems with aluminum wiring? (list at least three things)

Answer 29

1. Tends to creep out from under terminal screws.
2. Forms corrosion (oxide) that is an electrical insulator, resulting in greater resistance and overheating.
3. Is softer than copper and easier to damage when working with the wire.
4. Was more sensitive to poor workmanship.

Question 30

What improvements are typically recommended?

Answer 30

Replacement of receptacles with those designated CO/ALR and other
connections with components designated CUL. Special wire nuts can be
used. Pig-tailing is an option. COPALUM connectors can be used in some
areas, and split bolt connectors can be used.

Question 31

Where is the anti-oxidant grease typically used?

Answer 31

Anti-oxidant grease is typically used on stranded aluminum wires.

Question 32

Which aluminum wired receptacles are most likely to overheat?

Answer 32

Receptacles with heat generating appliances are most likely to overheat.
This includes outlets used for kettles, toasters, hair dryers, curling irons,
electric heaters, etc

Question 33

List nine outdoor wiring problems commonly associated with homes.

Answer 33

1. Indoor-type wire used outdoors
2. Garage door opener powered with extension cord
3. Wires within 5 to 7 ft of grade level or garage floor level
4. Wires not well secured to walls.
5. Wires run across roof surfaces.
6. Wires run through gutters or downspouts.
7. Overhead wires to out buildings are solid rather than stranded conductors.
8. Extension cords are used as permanent exterior wires.
9. Buried wires not suitable for use underground.