conduit fill % on drawing

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coop3339

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Anyone know of a reason to include conduit fill % on a drawing? I have been asked to include this and could not think of how it could be useful. If you wanted to change the fill or size of the conduit you would have to do a calculation anyway. It seems like a waist of time and plan space to me.
 
coop3339 said:
Anyone know of a reason to include conduit fill % on a drawing? I have been asked to include this and could not think of how it could be useful. If you wanted to change the fill or size of the conduit you would have to do a calculation anyway. It seems like a waist of time and plan space to me.
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Several reasons:
1. To prove you've done your calculation
2. To document space in the conduit available for future use, if applicable. Understand that it is the responsibility of the person using it in the future to make sure ampacity is still acceptable after its use.
3. To identify that you are taking advantage of the "nipple rule" in certain cases, where you are permitted to have a tighter fill.
4. To give the contractor information that would assist in making the decision to upsize for a particularly difficult pull.
5. To give the contractor information that would assist in upsizing fittings such as L-bodies, that are generally insufficient when sized exactly equal to the conduit trade size.
6. To rethink the size needed, when making the transition among multiple conduit types as needed for different environments. Understand that not all types of the same trade size have the same interior diameter. Need to build schedule 40 PVC in the trench, but schedule 80 when emerging above ground? Will the same trade size still work?

I think #4 and #5 are the most likely applications of putting this information on your drawings. Understand that we have our academic rules about sizing conduits, but in practice they can be tighter than you really want to go. If the contractor sees a particularly difficult pull, and sees that it is at 38% fill, that would be a case when it is best to increase the size for the practicality of the pull.
 
Carultch said:
Several reasons:
1. To prove you've done your calculation
2. To document space in the conduit available for future use, if applicable. Understand that it is the responsibility of the person using it in the future to make sure ampacity is still acceptable after its use.
3. To identify that you are taking advantage of the "nipple rule" in certain cases, where you are permitted to have a tighter fill.
4. To give the contractor information that would assist in making the decision to upsize for a particularly difficult pull.
5. To give the contractor information that would assist in upsizing fittings such as L-bodies, that are generally insufficient when sized exactly equal to the conduit trade size.
6. To rethink the size needed, when making the transition among multiple conduit types as needed for different environments. Understand that not all types of the same trade size have the same interior diameter. Need to build schedule 40 PVC in the trench, but schedule 80 when emerging above ground? Will the same trade size still work?

I think #4 and #5 are the most likely applications of putting this information on your drawings. Understand that we have our academic rules about sizing conduits, but in practice they can be tighter than you really want to go. If the contractor sees a particularly difficult pull, and sees that it is at 38% fill, that would be a case when it is best to increase the size for the practicality of the pull.
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While those reasons are fine and dandy,it will come down to whether the person making decisions has the authority to deviate from sealed and/or approved plans.
 
Smart $ said:
While those reasons are fine and dandy,it will come down to whether the person making decisions has the authority to deviate from sealed and/or approved plans.
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I have to agree here, if the installer is not permitted to deviate from the plans, what good does any information on calculations/data used to arrive at what was specified really do for the installer?

If you are trying to impress a plans inspector - I can see putting false data for the fill getting overlooked easily unless it is something way out of ordinary or they get out the code book and calculator and double check for accuracy. If you specify 4-500kcmil conductors and a 3 inch raceway they may not look any further as that would typically be code compliant even though you could have wrong fill data listed.
 
Carultch said:
Several reasons:
1. To prove you've done your calculation
2. To document space in the conduit available for future use, if applicable. Understand that it is the responsibility of the person using it in the future to make sure ampacity is still acceptable after its use.
3. To identify that you are taking advantage of the "nipple rule" in certain cases, where you are permitted to have a tighter fill.
4. To give the contractor information that would assist in making the decision to upsize for a particularly difficult pull.
5. To give the contractor information that would assist in upsizing fittings such as L-bodies, that are generally insufficient when sized exactly equal to the conduit trade size.
6. To rethink the size needed, when making the transition among multiple conduit types as needed for different environments. Understand that not all types of the same trade size have the same interior diameter. Need to build schedule 40 PVC in the trench, but schedule 80 when emerging above ground? Will the same trade size still work?

I think #4 and #5 are the most likely applications of putting this information on your drawings. Understand that we have our academic rules about sizing conduits, but in practice they can be tighter than you really want to go. If the contractor sees a particularly difficult pull, and sees that it is at 38% fill, that would be a case when it is best to increase the size for the practicality of the pull.
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Hillbilly Wax , Especially #4 & #5 .


Don
 
petersonra said:
In general, just having the boss direct something be done is adequate reason to do it.
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A friend of mine was an IT manager for the court system in a big city. One day his manager (think "pointy haired boss" from Dilbert) walked into his office with a spreadsheet of the IP numbers of all the devices on their network. He said he didn't like all the gaps in the numbering; he tasked my friend with changing the numbering scheme so that all the unused numbers would be at the end of the list. It was a lot of work and accomplished nothing at all. My friend made sure his manager could never find that spreadsheet again.
 
ggunn said:
A friend of mine was an IT manager for the court system in a big city. One day his manager (think "pointy haired boss" from Dilbert) walked into his office with a spreadsheet of the IP numbers of all the devices on their network. He said he didn't like all the gaps in the numbering; he tasked my friend with changing the numbering scheme so that all the unused numbers would be at the end of the list. It was a lot of work and accomplished nothing at all. My friend made sure his manager could never find that spreadsheet again.
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I'm thinking more of the "pointy headded CEO" from Dilbert. The PHB vaguely understands Dilbert's job, and the CEO vaguely understands the PHB's job.
Dilbert_comic_strip_for_02_25_2014_from_the_official_Dilbert_comic_strips_archive_.jpg
 
ggunn said:
A friend of mine was an IT manager for the court system in a big city. One day his manager (think "pointy haired boss" from Dilbert) walked into his office with a spreadsheet of the IP numbers of all the devices on their network. He said he didn't like all the gaps in the numbering; he tasked my friend with changing the numbering scheme so that all the unused numbers would be at the end of the list. It was a lot of work and accomplished nothing at all. My friend made sure his manager could never find that spreadsheet again.
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these days there are not all that many devices with fixed IP addresses. Most are assigned by the server as needed.

However, if for some reason you are assigning fixed IP addresses, it makes sense to keep the unused ones in a block.
 
petersonra said:
these days there are not all that many devices with fixed IP addresses. Most are assigned by the server as needed.

However, if for some reason you are assigning fixed IP addresses, it makes sense to keep the unused ones in a block.
Click to expand...

In this case it was static IP's on a big intranet. As machines moved off the network (which they did all the time for whatever reason), gaps appeared. In order to close the gaps he had to reassign IP numbers to practically every device on the network, which achieved nothing at all except to satisfy the uninformed desire of his boss not to see gaps in the numbers.
 
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