this is what I came up with (doesn't mean it's right)

1) 210.23 a 2
2) read 392. probably in 392.22
3)


430.24 Several Motors or a Motor(s) and Other
Load(s). Conductors supplying several motors, or a motor(
s) and other load(s), shall have an ampacity not less
than the sum of each of the following:
(1) 125 percent of the full-load current rating of the highest
rated motor, as determined by 430.6(A)
(2) Sum of the full-load current ratings of all the other
motors in the group, as determined by 430.6(A)
(3) 100 percent of the noncontinuous non-motor load......

430.6 Ampacity and Motor Rating Determination. The
size of conductors supplying equipment covered by Article
430 shall be selected from the allowable ampacity tables in
accordance with 310.l5(B) or shall be calculated in accordance
with 310.15(C). Where flexible cord is used, the size
of the conductor shall be selected in accordance with 400.5.
The required ampacity and motor ratings shall be determined
as specified in 430.6(A), (B), (C), and (D).
(A) General Motor Applications. For general motor applications,
current ratings shall be determined based on
(A)(l) and (A)(2).
(1) Table Values. Other than for motors built for low
speeds (less than 1200 RPM) or high torques, and for multispeed
motors, the values given in Table 430.247, Table
430.248, Table 430.249, and Table 430.250 shall be used to
determine the ampacity of conductors or ampere ratings of
switches, branch-circuit short-circuit and ground-fault protection,
instead of the actual current rating marked on the
motor nameplate. Where a motor is marked in amperes, but
not horsepower, the horsepower rating shall be assumed to........

table 430.248
1/6 hp = 4.4
1/4 hp = 5.8

feeder ampacity min = 1.25 * 5.8 + 5.8 + 4*4.4 = 30.65amps

310.15 B

75 degree table for #10 is 35 amps



the kiln question)

this is what I come up with:
vd = 1.73 kil/kcmil = 1.73 *12.9 *

to find current

at 240 volt you have 9500 VA
9500/240=39.58amps

v=ir so r=240/39.58 = 6.06

so at 208 volts, i = 208/6.06 = 34.32

now back to voltage drop

vd = 1.73 * 12.9 * 34.32 * 80 /26240 =2.34 volts

2.34 volts/208volts = .01 = 1%

4)

part IV spas and hot tubs

680.42 Outdoor Installations. A spa or hot tub installed
outdoors shall comply with the provisions of Parts I and II
of this article, except as permitted in 680.42(A) and (B),
that would otherwise apply to pools installed outdoors.
(A) Flexible Connections. Listed packaged spa or hot tub
equipment assemblies or self-contained spas or hot tubs
utilizing a factory-installed or assembled control panel or
panelboard shall be permitted to use flexible connections as
covered in 680.42(A)(1) and (A)(2).
(1) Flexible Conduit. Liquidtight flexible metal conduit or
liquidtight flexible nonmetallic conduit shall be permitted.
(2) Cord-and-Plug Connections. Cord-and-plug connections
with a cord not longer than 4.6 m (IS ft) shall be permitted
where protected by a ground-fault circuit interrupter.






(part II)
680.21 Motors.
(A) Wiring Methods. The wIrIng to a pool motor shall
comply with (A)( I) unless modified for specific circumstances
by (A)(2), (A)(3), (A)(4), or (A)(S).
(1) General. The branch circuits for pool-associated motors
shall be installed in rigid metal conduit, intermediate
metal conduit, rigid polyvinyl chloride conduit, reinforced
thermosetting resin conduit, or Type MC cable listed for the
location. Other wiring methods and materials shall be permitted
in specific locations or applications as covered in
this section. Any wiring method employed shall contain an
insulated copper equipment grounding conductor sized in
accordance with 2S0.122 but not smaller than 12 AWG.
(2) On or Within Buildings. ""here installed on or within
buildings, electrical metallic tubing shall be permitted.

 

You have a kiln that is 240 volt single phase that is rated at 9.5KVA. The kiln will be feed from a 120/208 volt panel, 80 feet away. What would the percent of voltage drop be? The kiln will have a 60 amp breaker protecting it. The wire will be #6 AWG THHN with 75 degree lugs.

My answer: 1.72%

Correct: Not given

I find the kiln question to be a bit of a mystery.

Should I:
A: Treat the kiln as a fixed 9.5 kVA load, that will control its power consumption to be 9.5 kW?

or
B: treat the kiln as a resistive heater of fixed ohms in its coil? It will not consume as many amps of power, if this is the case.

 

did you read my answer ? you have to figure out the amps at the reduced voltage by determining R from the kw at the rated voltage.

 

Question 1 is kind of a trick question. Read 210.23(A)(2).

 

..........

 

You have a multifamily dwelling that has a 60 amp single phase 120/240 service. Each unit will be feed with SE cable marked XHHW-2. It will be ran in uninsulated voids in the multifamily dwelling walls. Each feeder will serve only the unit. What's the minimum size SE cable you will need for each 100 amp dwelling unit? (All lugs rated 75 degree)

My answer: #1 AL

Correct answer: #2 AL
Not really sure on this one.

Look at 310.15(B)(7) 1-4

In the 2014 NEC Table 310.15 (B)(7) was removed so now you must do the calculations, you can check your calculations by looking at the table in the 2011 NEC....:whistling2:


From Annex D, Example D7 Sizing of Service Conductors for Dwelling(s) [see 310.15(B)(7)]
Service conductors and feeders for certain dwellings are permitted to be sized in accordance with 310.15(B)(7).
If a 175-ampere service rating is selected, a service conductor is then sized as follows:
175 amperes × 0.83 = 145.25 amperes per 310.15(B)(7).
If no other adjustments or corrections are required for the installation, then, in accordance with Table 310.15(B)(16), a 1/0 AWG Cu or a 3/0 AWG Al meets this rating at 75°C (167°F).

 

Thanks to everyone who replied. Reading everyone's responses and looking back at what I wrote down, I can see where I went wrong. There are code sections that I didn't think about looking in so its nice to see where the answers come from.

What I still don't get is why liqidtight is not part of the answer for the hot tub but EMT is. It is acceptable for flexible connections for the motor and EMT has restrictions.

 

What I still don't get is why liqidtight is not part of the answer for the hot tub but EMT is. It is acceptable for flexible connections for the motor and EMT has restrictions.

Heres what I found.

(I see its the same article Wildleg posted, but with the length of flex limitation. Mine is from the NEC 2011)



680.42 Outdoor Installations. A spa or hot tub installed outdoors
shall comply with the provisions of Parts I and II of this
article, except as permitted in 680.42(A) and (B), that would
otherwise apply to pools installed outdoors.
(A) Flexible Connections. Listed packaged spa or hot tub
equipment assemblies or self-contained spas or hot tubs
utilizing a factory-installed or assembled control panel or
panelboard shall be permitted to use flexible connections as
covered in 680.42(A)(1) and (A)(2).
(1) Flexible Conduit. Liquidtight flexible metal conduit or
liquidtight flexible nonmetallic conduit shall be permitted
in lengths of not more than 1.8 m (6 ft) external to the spa
or hot tub enclosure in addition to the length needed within
the enclosure to make the electrical connection.

 

Probably due to the 8' part. Nothing over 6' without exceptions



Sent from my house using 2 cans and a string!

 

maybe I'm wrong, but my interpretation of the hot tub question is that the wiring methods shown in the correct answer are always allowed, and the ones you chose are allowed under certain conditions, but the conditions were not specified.

 

The option of LFMC in his question stated it was 8'

I agree with your interpretation also.