Final Topics Flashcards
(33 cards)
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
c) polarity of some receptacles
e) operation of all GFCIs
List four different branch wire materials you might see.
- Copper
- Aluminum
- Copper clad aluminum
- Solder-dipped copper
Describe three different cable types you might see.
- NM, Romex, Loomex
- UF or NMWU
- BX (AC-90), armored cable
- Knob-and-tube
What is the difference between insulation and sheathing?
Insulation is around the individual wires, and sheathing forms the cables by wrapping around the insulated wires.
Which of the following wires are stranded?
a) #14
b) #12
c) #10
d) #8
e) #6
d) #8
e) #6
The most common wire size for branch household circuits is what gauge?
14
What is an overloaded circuit?
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.
How are extension cords different from permanent wiring?
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.
When a wire leaves a box, how far should it run before it is supported or secured?
Twelve inches
Running along the length of the wire, how far apart should the supports be?
Four and a half to five feet
What are the issues on running wire through steel studs?
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.
Give five examples of poor locations for wiring.
- Exposed to damage, on wall surfaces for example
- Under carpets
- Close to the edge of studs or joists
- In ductwork
- Against pipes, ducts, exhaust flues vents, chimneys or other heat sources
List 17 common branch circuit wire problems.
- Damaged
- Not well secured
- Loose connections
- Open splices
- Wires too close to ducts, pipes, vents, chimneys, and flues
- Wires too close to the edge of studs or joists
- Wires run through steel studs without protection
- Exposed wires on walls or ceilings
- Exposed wires in attics
- Wire run under carpets
- Cable used outdoors
- Buried cable not rated for buried use
- Overhead wires not stranded
- Household wire used as extension cords
- Undersized wire
- Improper color coding
- Abandoned wire
Give four examples of damaged wire.
- Cut or pinched
- Chewed on by animals
- Burned wire
- Wire with brittle or cracked insulation
List three methods for securing wire ends.
- Terminal screws
- Push-in connectors
- Solderless connectors
What is meant by ‘open splice’?
An open splice is a connection that is not made inside a junction box.
Wire should be how far away from ducts and pipes?
One inch
Wire should be how far away from the edge of studs.
One and a quarter inches
A grommet is:
A grommet is a fitting that protects cable from the sharp edges of steel
studs.
Wires should not be run on wall surfaces without –
Mechanical protection
What is the problem with running wire across the top of the attic ceiling joists?
Because they are not visible and may be stepped on
Abandoned wire should be –
Removed
Describe how knob-and-tube wiring is visibly different from modern cable.
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.
Does knob-and-tube wiring have a ground wire associated with it?
No
