Neutral Feeder Calc.

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house of power

Member
Location
Texas
Can some one give me the steps to figuring this problem:

Calc. neutral feeder for a 2000 square foot assembly hall. 120 / 240. Lighting load is balanced. the answers given were

8.3
31.7
52.1
68.8

I assume the 1 VA x 1.25 continous load?
 
B

bphgravity

Senior Member
Location
Florida
Re: Neutral Feeder Calc.

Based on the answers you have provided, only one is even close to realistic and would make sense. That should be a tip off. :)
 
M

mm

Member
Re: Neutral Feeder Calc.

HEY, HOUSE OF POWER, I MISSISD THAT QUESTION ON THE ICC EXAM . THERE WERE SEVERAL POORLY WORDED QUESTIONS ON THE EXAM. SUCH AS THE LIGHT IN THE CLOTHES CLOSET, OCPD LOCATION, AND ALL OF THE PLAN READING QUESTION WERE NOT CLEAR. I WILL RETAKE THE EXAM.. I HEAR THAT WHEN AN EXAM IS GIVEN AGAIN, IT WILL NOT BE THE SAME AS THE FIRST ONE. IS THIS TRUE ? I MISSED THE PASSING SCORE BY 3 POINTS. SO IF I RETAKE THE SAME EXAM ,I KNOW I WILL PASS IT. NEEDED 75 TO PASS. I THINK I WILL TRY IT AGAIN IN AUGUST
 
M

mm

Member
Re: Neutral Feeder Calc.

NO, I TOOK THE MASTER ELECTRICAL FROM ICC, I TOOK THE INSPECTOR CERTIFICATION FROM IAEI/NFPA, NO RESULTS BACK FROM NFPA,IAEI FOR THE TEST I TOOK IN APRIL OF THIS YEAR.
 
dereckbc

dereckbc

Moderator
Staff member
Location
Plano, TX
Re: Neutral Feeder Calc.

MM please turn off the CAPS. It gives the impression you are shouting and is hard to read.
 
H

house of power

Member
Location
Texas
Re: Neutral Feeder Calc.

I took the exam and got a 73. I have several questions that I would like to talk with someone about if they have taken the test and passed recently. The plan reading is garbage. The plan for the written test is different than the computer test. If anyone has some time and would like to help please PM me and I can give you a call and chat. Your time would be greatly appreciated. Thanks in advance.

Edited to remove e-mail address and insert the abbreviation for Private Message. This will prevent the "mining" of e-mail addresses from the forum. Charlie :D

[ June 23, 2004, 05:35 PM: Message edited by: charlie ]
 
B

bphgravity

Senior Member
Location
Florida
Re: Neutral Feeder Calc.

Just post your questions here and give everyone a shot answering them. Sometimes you will get a completely new perepective or method that won't be clear from just one person. :)
 
roger

roger

Moderator
Staff member
Location
Fl
Occupation
Retired Electrician
Re: Neutral Feeder Calc.

I don't think that is what Bryan was saying.

In N.C. when you take the state exam you don't take anything in the room except yourself, and likewise, you don't leave with anything except yourself.

If I think I may have missed a question out of 100 and somehow remember the exact wording of said question, I think the testing agency would be hard pressed to accuse me of giving out test info if I tried to ask an opinion here or anywhere.

Roger
 
H

house of power

Member
Location
Texas
Re: Neutral Feeder Calc.

LOL, I have about 27 questions I need help with. Let me think up some of the ones I really had a problem with besides the plan reading.
 
H

house of power

Member
Location
Texas
Re: Neutral Feeder Calc.

1.) Overcurrent devices shall be located where they will not :

A. Be exposed to mechanical injury
B. Vicinity of easily ignitable material
C. Both
D. Neither

I picked B only because the code says physical injury on answer A, but was told it is the same thing.

2. 25 Ft. feeder tap from 500 KCMIL THWN protected w/ 500 amp main breaker. The feeder tap______________

A. Minimum ampacity of 150 amps
B. 3/0 THWN if on a 200 amp breaker
C. Both
D. Neither

I picked B, but am not sure about this one.

3.Conductors with different insulation ratings that are less than 600v in same raceway regulated by code:

A. max operating voltage not to exceed the lowest rating of any conductor
B. Conduit fill limited to 10%
C. conductors of seperate ratings grouped and bound
D. lower rated conductors to be identified w/ yellow or blue insulation.

Lets try these out for now and see what you guys think.

[ June 22, 2004, 09:03 PM: Message edited by: house of power ]
 
B

bphgravity

Senior Member
Location
Florida
Re: Neutral Feeder Calc.

1. Per 240.24(C) and (D), overcurrent devices shall not be exposed to physical damage nor in the vicinity of easily ignitible materials. The answer "A" is poor in that injury is not something I would assoicate with an inanimate object, however I think it can be reasoned that "C" is the correct answer.

2. I don't get this questions numbers. A 500-kcmil protected by 500A OCD. :eek: Since the question does not specify transformer, I assume the section would be 240.21(B)(2). None of the answers apply, so I believe "D" is the correct answer.

3. The correct answer is "A" per section 300.3(C)(1).
 
don_resqcapt19

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
Re: Neutral Feeder Calc.

Bryan,
For, question 2, I agree that the 500 kcmil shouldn't have a 500 amp OCPD, but I think that they are looking for answer B as the correct answer. 240.21(B)(2)(1) would prohibit the use of the 150 amp conductor in answer A because it is less than 1/3 the ampacity of the feeder OCPD. 3/0 copper is 200 amp wire and would be permitted as a tap conductor from a feeder protected at 500 amps per 240.21(B)(2)(2).
Don
 
B

bphgravity

Senior Member
Location
Florida
Re: Neutral Feeder Calc.

The part I didn't get with that answer is where it says, "if on a 200A breaker". If its a tap conductor, it doesn't have its own overcurrent protection. I suppose it could mean that the tap terminates at a 200A breaker. The questions are written very poorly.
 
roger

roger

Moderator
Staff member
Location
Fl
Occupation
Retired Electrician
Re: Neutral Feeder Calc.

house of power, are these questions worded correctly, after all isn't this by memory.

Roger
 
don_resqcapt19

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
Re: Neutral Feeder Calc.

Brayn,
I just assumed that the 200 amp OCPD was at the load end of the tap conductor.
Don
 
M

mm

Member
Re: Neutral Feeder Calc.

house of power, I took the same dumb test that you took. most of the questions did not make sense. they were trick questions. I have been an the electrical field for 25 years, I have always passed electrical exams with no problems, but the icc master electrical exam is a joke. If a test is based on the nec it should be worded as in the code. ,and take out the guess work .
 
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