JM Electrician Flashcards
Max Distance between straps for a straight 1” rigid conduit run is? (RMC/GRC)
Table 344.30 (B)(2)
12 FEET
NM cable is “not Permitted” in concrete.
334.12 (A)(9)
True
What is the classification for a receipt. 16”AFF in a garage?
511.3(A)
Unclassified
Define Motor Controller.
430.2-controller
Make and break current only
What is the max. Resistance of Rod and Plate Electrodes?
250.56
25 OHMS
Type UF cable “cannot” be used as a…
340.12(1)
Service Entrance Cable
Where is a disconnect prohibited?
230.70(A)(2)
Bathrooms
How deep must a 30A Type UF cable used for landscape lighting at a residence be buried?
Table 300.5
6 inches
Overhead conductor clearance for swimming pools is?
Table 680.8
22 1/2 feet
What is the min. size wire you can use for parallel feeders?
310.4
1/0 awg
Wet-Niche underwater luminare forming shells in contact w/pool water must be?
680.23(B)(1)
Brass or other approved corrosion resistant metal.
What is required for taps made on direct burial cables?
110.14(B) or 300.5(C)
listed means
The use of a ladder to access or remove without damaging the building is considered to be…..
100 definitions
Accessible
What size schedule 40 PVC is required for 5 conductors that have across sect. area of 3 1/2?
Chap. 9 Table 4
3 1/2 inches
How far must your cable be installed from the edge of a stud to be protected from damage?
300.4(D)
1 1/4 inches
How far must you strap a cable leaving a box w/ breakers and conduit seals?
501.15(A)(1)
18 inches
In walls w/ combustible material, the box must be?
312.3
Flush w/ the wall or project there from
How many switched receipts. are required in a storage area?
210.70(A)(3)
1
If there is more than one service disconnect on the same property….
225.33(A)
They must be grounded together.
No more than 6 disconnects
NM cable is permitted in a unfinished basement!
334.15(C)
True
What is the min. depth of wiring space if you are servicing 277V circuit w/ exposed live parts on both sides?
Table 110.26(A)(1)
4 feet
What receipt. rating are you allowed on a 20A circuit breaker?
Table 210.21(B)(3)
15 and 20 Amp recepts.
What is the minimum bend radius for NM cable w/a radius of 1/4”?
334.24
(.25x5=1.25)
1 1/4 inch
- The bending radius shall not be less than 5x the diameter of the cable.
How many type TW #14 wires can you put in 3/8” FMC w/ the fitting on inside of conduit?
348.22 / Table 348.22
2
Devices mounted on finished surfaces that are flammable(wood) shall be…
314.20
mounted flush with or project there from
Over current protection “shall not” be required for conductors from a battery rated less than _____ volts if the battery provides power for starting, ignition, or control of prime movers.
48 volts
Boxes at ceiling-suspended fan outlets “can not”support more than….
35 lbs
unless they are listed for and marked w/ the max weight to be supported.
3 phase Y transformer?
0
Elect. equipt. w/ exposed parts on one side requires a working distance of?
3 feet
A JW encounters a sub-panel fed w/ type SE cable. What must he do?
Make sure all grounded and ungrounded conductors have insulation
The code recognizes 2 conditions for the derating of conductors, it is the combo of these that ultimately determines the amount a conductor can be derated.
- Ambient temp.
2. # of conductors in a conduit
Is it permitted to use steel pipe and alum. fittings and also alum. RMC w/ steel fittings where not subject to corrosive influences?
YES
An NM cable is installed in an air duct, is this allowed?
NO!
What is the max distance you can run #12 w/ a load of 8amps?
150 feet
What size NM cable for 240V, 15,000VA?
4
In a crawl space where there is no storage area or equipment, do you need to install a switch or receipt.?
NO!
The reason for parallel feeders is to?
Reduce inductive heat
Why must there be ventilation in a room where you store batteries?
To prevent an explosive air/gas mixture
Which method is approved for the bonding of a clothes dryer?
None of the above
When there is more than 1 ground rod, how far must the second be placed?
6 feet
What is the max. number of switches that may be used as the disconnecting means for a feeder?
6
Service mast as supports must be…
225.17 or 230.28
ADEQUATE STRENGTH or be supported by braces or guys to safely withstand the strain imposed on it.
Parallel feeders must have…
310.4 (1-5) Must be terminated in the same manner/ Same size/ Same Material/ Insulation type/ Length
The min. headroom required for switchboards is?
110.26(E)
6 1/2 feet
Are GFI receipts. required in bathrooms and attached garages?
210.8(A)(1-8)
YES
Bathrooms, Garages, outdoors, crawlspaces, unfinished basements, kitchen, boathouse, laundry/ utility/ wet bar
Why must you install conduit in a continuous manner?
300.10
Far a safe continuity path back to the service.
Electrical Signs are to be…
600.3
LISTED! and installed in conformance w/ that listing, unless otherwise approved by special permission
How far must you strap NM cable from an NM box?
334.30
12 inches
What does the interrupting rating of a circuit breaker protect?
100 definitions
Max current/amps of conductor
The two main safety concerns in a hospital in a power outage are…
517.33
Illumination and telephone Equipt. rm
What is the min. ampacity for a 3 phase, 23v, 15hp inductive type motor?
Table 430.250
42 Amps
What circuit must operate in the “life safety” branch of health facilities?
Automatically operated doors used for building egress
How many 20 amp lighting circuits are required for a 3000 sqft residence?
5
What is the min. length of cord on kitchen waste disposal?
18 inches
Objectionable current flow…
Installed at different location
What is the inverse time circuit breaker required for a motor rated for 20a?
20x250%=50A
What is the classification for a garage w/out vents where flammable material is stored?
Class 1, Div.2
“Sample” A metal box w/clamps is to contain 2- 14/2 NMC w/GRD, 1- 14/3 NMC w/GRD and one receipt. what is the min. size box(in cu. in.) permitted?
314.16 (B)(1.5)
7#14@2.0 cu.in.= 14 cu.in
1-clamp(#14)= 2 cu.in
2-strap(#14)= 4 cu.in
1-ground(#14)= 2 cu.in
22 cu.in“SAMPLE” A conduit has 3 #12 thru the riffing; 2-#12 that enter and splice in the fitting; 2-#12 that leave the fitting.
What is the min. cubic inch capacity that the manufacture must have marked on the fitting?
314.16(C)(2) / 314.16(B)(1) table #12= 2.25 cu.in *a conductor which passes thru counts as 1. 3-#12- 3x2.25=6.75 4-#12- 4x2.55=9 6.75+9=15.75 cu.in 15.75 cu.in
“SAMPLE” What is the ampacity of 4 - 4/0 THHN copper conductors in a raceway installed thru an smb. temp. of 40*C
Table 310.15(B)(2)(a) 4-6 conductors 80% 4/0 230A 230x.80=184A 82% derate for 45*C 184Ax.82=150.88 150.88A
- Abandoned Cond. & cords
NO unless approved
- Smoke detectors
SHALL NOT
- Show windows
18” within
- Service disconnect
Inside and out of building
- Clark County New
Concrete Encased
