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21

Originally Posted By: pabernathy
This post was automatically imported from our archived forum.


do we not want to wait for other answers?

–
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22

Originally Posted By: jwortham
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Wouldn’t 3 phase be a 208/120 VAC circuit since line-neutral would be 120 VAC on that system?

23

Originally Posted By: tallen
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45 amp min breaker at 100 %

–
I have put the past behind me,


where , however, it now sits, making rude remarks.


www.whiteglovehomeinspections.net

30 Oct 2003-- 29 Nov2005

24

Originally Posted By: tallen
This post was automatically imported from our archived forum.


jwortham wrote:
Wouldn't 3 phase be a 208/120 VAC circuit since line-neutral would be 120 VAC on that system?


That depends on weather it is a wye or a delta.

--
I have put the past behind me,
where , however, it now sits, making rude remarks.

www.whiteglovehomeinspections.net

30 Oct 2003-- 29 Nov2005
25

Originally Posted By: tallen
This post was automatically imported from our archived forum.


pabernathy wrote:
do we not want to wait for other answers?




IU\ am correct huh?

--
I have put the past behind me,
where , however, it now sits, making rude remarks.

www.whiteglovehomeinspections.net

30 Oct 2003-- 29 Nov2005
26

Originally Posted By: bkelly2
This post was automatically imported from our archived forum.


Somewhere Joe T is smiling icon_wink.gif

–
“I used to be disgusted, Now I try to Be amused”-Elvis Costello

27

Originally Posted By: pabernathy
This post was automatically imported from our archived forum.


If you are refering to the 5HP motor question…no power factor needed in that equation…if no factor is listed per the NEC you have to assume ONE ( listed per code )…or none is needed in the equation…but 12 AWG is WAY too small…talk about a fire hazzard…lol


Remember NEC exams will not ask you anything to be factored in other than information given.

--
Paul W. Abernathy- NACHI Certified
Electrical Service Specialists
Licensed Master Electrician
Electrical Contractor
President of NACHI Central Virginia Chapter
NEC Instructor
Moderator @ Doityourself.com
Visit our website- www.electrical-ess.com

28

Originally Posted By: pabernathy
This post was automatically imported from our archived forum.


no not correct…the question was what size conductor for this motor with the information listed…

–
Paul W. Abernathy- NACHI Certified


Electrical Service Specialists


Licensed Master Electrician


Electrical Contractor


President of NACHI Central Virginia Chapter


NEC Instructor


Moderator @ Doityourself.com


Visit our website- www.electrical-ess.com

29

Originally Posted By: pabernathy
This post was automatically imported from our archived forum.


lol…I dont even know Joe…but I love a good debate of engineering math versus in the field math…icon_smile.gif

–
Paul W. Abernathy- NACHI Certified


Electrical Service Specialists


Licensed Master Electrician


Electrical Contractor


President of NACHI Central Virginia Chapter


NEC Instructor


Moderator @ Doityourself.com


Visit our website- www.electrical-ess.com

30

Originally Posted By: pabernathy
This post was automatically imported from our archived forum.


Oh also half the time I have to admit…We keep a ElectriCalc Pro Calculator in our truck just in case…way to many calculations to remember all of them.

–
Paul W. Abernathy- NACHI Certified


Electrical Service Specialists


Licensed Master Electrician


Electrical Contractor


President of NACHI Central Virginia Chapter


NEC Instructor


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Visit our website- www.electrical-ess.com

31

Originally Posted By: tallen
This post was automatically imported from our archived forum.


pabernathy wrote:
ok...here is one for you...very simple...

A 5hp motor is located 90 feet from a 120/240v panelboard. What size conductor should be used if the motor nameplate indicated 52 ampere at 115volts? Terminal rated for 75 degree C.

In the field type question....give it a shot ole sparky !


I did it what about you???

--
I have put the past behind me,
where , however, it now sits, making rude remarks.

www.whiteglovehomeinspections.net

30 Oct 2003-- 29 Nov2005
32

Originally Posted By: pabernathy
This post was automatically imported from our archived forum.


I know the answer…post yours…FIRST and how you came up with it fella…Old Sparky


Question reading 101....I did not ask you for the breaker size....I asked for the conductor size....

You stated : 45 amp min breaker at 100 %....not what I asked for in the question......

First thing we teach....read the question slowly and understand what the proctor is asking...lol

--
Paul W. Abernathy- NACHI Certified
Electrical Service Specialists
Licensed Master Electrician
Electrical Contractor
President of NACHI Central Virginia Chapter
NEC Instructor
Moderator @ Doityourself.com
Visit our website- www.electrical-ess.com

33

Originally Posted By: pabernathy
This post was automatically imported from our archived forum.


Aw heck…I am getting tired as it is past midnight here…


Here is the answer for all you electrical wiz people who know this....

CM= 2 x K x I x D
_____________
VD ( Voltage Dropped )


K= 12.9 Ohms, copper ( we always ASSUME copper in NEC calculations if not mentioned. )
I = 52 amperes at 115 volts
D = 90 feet
VD = 120 volts x 0.03= 3.6 volts

CM = 2 x 12.9 x 52 x 90
_______________( divided )
3.6 volts

= 33,540 CM ( Chapter 9, table 8 of the NEC )

Use a # 4 THHN.........be happy.....![icon_smile.gif](upload://b6iczyK1ETUUqRUc4PAkX83GF2O.gif)

--
Paul W. Abernathy- NACHI Certified
Electrical Service Specialists
Licensed Master Electrician
Electrical Contractor
President of NACHI Central Virginia Chapter
NEC Instructor
Moderator @ Doityourself.com
Visit our website- www.electrical-ess.com

34

Originally Posted By: pabernathy
This post was automatically imported from our archived forum.


Oh crap…I only need one more post to reach 100…so I will answer my other questions so I can get 100…yeeehhhaaaaaa ( it is late…sorry )


What is the current in ampere of a three-phase, 18KW, 208 volt load?

Easy one.... W
______
E x 1.732 ( square root of 3 )

Answer is : 49.96...rounding rule....up..up..up...50 Amps

or

What is the power loss in watts for a conductor tha carries 24 ampere and has a voltage drop of 7.2 volts?

Ok.....easy as well.....everyday electrician us it...

Question..what are you looking for? Power right....

P=ExI so E = 7.2 volts and I = 24 amps so....

Answer is 172.8 Watts lost per hour


Night all....

--
Paul W. Abernathy- NACHI Certified
Electrical Service Specialists
Licensed Master Electrician
Electrical Contractor
President of NACHI Central Virginia Chapter
NEC Instructor
Moderator @ Doityourself.com
Visit our website- www.electrical-ess.com

35

Originally Posted By: pabernathy
This post was automatically imported from our archived forum.


You know of course now Mr Allen…this means WAR…lol…You better get your calculator handy and your code book in sight…lol

–
Paul W. Abernathy- NACHI Certified


Electrical Service Specialists


Licensed Master Electrician


Electrical Contractor


President of NACHI Central Virginia Chapter


NEC Instructor


Moderator @ Doityourself.com


Visit our website- www.electrical-ess.com

36

Originally Posted By: jpope
This post was automatically imported from our archived forum.


While reading this thread, I heard a loud pop.


I think it was my brain. . . ![aiwebs_014.gif](upload://9EMgoh1wke3JUYRfZP3x3cMyzDA.gif)

--
Jeff Pope
JPI Home Inspection Service
"At JPI, we'll help you look better"
(661) 212-0738

37

Originally Posted By: pabernathy
This post was automatically imported from our archived forum.


I know Jeff… me and Mr. Allen got carried away at a Pi@@ing contest…lol…he removed his question which I still dont know if it is right or wrong…lol…so then I posted some everyday field electrician math questions and well…I got carried away…lol


Mr. Allen was a good sport about it........it was fun !

--
Paul W. Abernathy- NACHI Certified
Electrical Service Specialists
Licensed Master Electrician
Electrical Contractor
President of NACHI Central Virginia Chapter
NEC Instructor
Moderator @ Doityourself.com
Visit our website- www.electrical-ess.com

38

Originally Posted By: pabernathy
This post was automatically imported from our archived forum.


So I will leave with ONE additional EASY electrical calculation for everyone to answer while they read my long…winded…boring post…lol



Q : The true power of a single phase, 2.1 KVA load with a power factor of 91 percent is _________.

heck I will make it multiple choice since this is NOT a question I came up with...lol...but I know how to calculate it.

a.) 2.1kW b.) 1.91 kW c.) 1.75kW d.) 1,911 kW

Ok all you HI sparkies....fire away.....


EDIT # 1 - It is 9:55AM still not attempts to answer this question.

--
Paul W. Abernathy- NACHI Certified
Electrical Service Specialists
Licensed Master Electrician
Electrical Contractor
President of NACHI Central Virginia Chapter
NEC Instructor
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39

Originally Posted By: jwortham
This post was automatically imported from our archived forum.


I’ll take a shot.


Since Pf=True Power/ Apparent Power

.91=x / 2.1

2.1KVA x .91=1.911

Answer is B.

40

Originally Posted By: pabernathy
This post was automatically imported from our archived forum.


Award goes to :jwortham


The correct answer is : 1.91kW

--
Paul W. Abernathy- NACHI Certified
Electrical Service Specialists
Licensed Master Electrician
Electrical Contractor
President of NACHI Central Virginia Chapter
NEC Instructor
Moderator @ Doityourself.com
Visit our website- www.electrical-ess.com