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Discussion Starter · #1 ·
Hello.
To look at it in the field is completely different than the math, but I would like to know, can anyone tell me mathematically how to solve the following questions.

75 foot long 1" EMT with two pull boxes requires how many support clips? (With the rules for pull box and 1" EMT distance)

80 foot 3/4" EMT with two NO boxes require how many support clips? (With rules for 3/4')

When I just do a simple divide, the answer I get for the first one is 11.49 but the right answer is 12.
When I do the second question, I get 16.25 but the right answer is 16.

So I am wondering, A) Can someone give me the breakdown to figure out each, so I can B) determine why in one answer you round up and the other, you round down?

Thank you.
 

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Do you know how to read the conduit section in the code?
This question seems like someone's home work.

When I took my IBEW JW test, I failed. Until I went to my truck and got the code book and proved that 10 of the answers in the key were WRONG. They might have just passed me to shut me up.
 

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By my memory and math...
#1: 75' of 1" conduit with a 6' spacing, and 2 pull boxes. I'm assuming they are at each end of the run. 75'-3'=72'. 72÷6=12, plus the first support would be 13 supports.
#2: 80' of 3/4" conduit with a 5' spacing, and no boxes. 80'÷5=16 supports. Assuming on this one that one end is supported by a wall or something to start.
 

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Hi! Thank you :) The apparent "right" answer for 12 is really throwing me off.
This is electrician talk, not homework help for people who don’t feel like reading.
 
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Discussion Starter · #8 ·
You sad, sad person. Just because you don't know the answer, does not mean you have to respond so negatively. Just move on. I'm sure you have better things to do with your time.

If you in fact do know the answer, please by all means, let me know so that you can prove me wrong and boost your confidence (I think you need it.) Then you can say you've actually positively contributed to society.

Otherwise, have a nice day.
 

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Electrical contractor 37 years. Electrical inspector 2 years
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You want a NEC answer?


Six straps, a pair at 5 ft from the boxes, then 15 ft, and then 25 ft. This uses exception 1.
NEC is 3 feet from the box then every 10 feet. This is a problem with many tests. Some do not allow the exceptions others do. Then the test will give the choices of 1,3, 5, 6. So what would be the correct answer? You qualified your answer by saying exception 1. But the OP is from Canada so the CEC.
 

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NEC is 3 feet from the box then every 10 feet. This is a problem with many tests. Some do not allow the exceptions others do. Then the test will give the choices of 1,3, 5, 6. So what would be the correct answer? You qualified your answer by saying exception 1. But the OP is from Canada so the CEC.
I know, that’s why he should have placed it in the correct forum to start with.
 

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Hi! Thank you :) The apparent "right" answer for 12 is really throwing me off.
Well, on the Job, I'd use 13 straps ... 'cause I still use feet :cool:

Try the formula Glen used, but change it to Meters, or use 6.56 feet between straps.
 
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