Determining the number of fittings

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Old 08-04-15, 09:29 PM
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Exclamation Determining the number of fittings

How to determine the number of fittings like couplings, locknut and bushings, connectors, elbow, etc?
For example, a 145 length of EMT pipe needs how many couplings and connectors? This is when estimating a plan.Is there a specific formula to get the number of fittings?
 
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Old 08-04-15, 10:10 PM
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Welcome to the forums.

Plan the job out on paper so that you can get your counts.

Each box in the line will need one or two connectors.
You will need at least one coupling per piece of pipe depending on how many boxes will be in the line or how many mistakes you make.
Elbows are pull ell's or LB's in electrical work. You need an LB if you're going around a square corner.

A 1/2" EMT bender would be nice to have for bending actual elbows.

As an electrician we buy our 1/2" fittings in boxes of 50 so we don't count what we need.
Larger sizes..... usually over 3/4" are counted.

Have extra EMT on hand to cover mistakes.


For example..... you are running 145' of pipe from a panel and connecting to four receptacles.
You have four boxes. Three boxes need two connectors and one box needs one.
You need one connector at the panel. That's 8 connectors.
Get 15 couplings to be on the safe side.
You need 1/2" EMT straps for attaching the conduit to the wall.
1/2" won't require any bushings.
 
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Old 08-04-15, 11:06 PM
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Thank you for the response. Another question is what is the difference between pullbox, junction box, utility box and square box. Is there any specific uses to them like utility box is for receptacles, junction box is for lighting fixtures, etc ?

Sorry for asking this other question without opening a new thread.
 
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Old 08-04-15, 11:10 PM
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Another sir, how to determine locknut and bushings in IMC? Does it depends with the quantities of boxes to be used?
 
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Old 08-05-15, 12:02 AM
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We use what we call 1900 boxes (4" square) for just about everything when we pipe. The box is universal and you can put on a switch, receptacle, or blank plate. There are plenty of knockouts and room for plenty of wiring and splices.

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With IMC (threaded pipe) you will need two locknuts every time the pipe connects to a box. Depending on the diameter of the pipe.... a bushing would be good at each box connection.

IMC is expensive, heavy and time consuming to install. If you cut the pipe you need to re-thread it or use a compression fitting.

What is the project you are working on ?
 
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Old 08-05-15, 01:13 AM
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Nice explanation sir. I'm starting to get it now.

Actually I am a quantity surveyor but new in the job because I am a fresh graduate so I am having so much question. The project was a basketball gym. I have already got the other quantities but the fittings of the pipes confuse me, as well as the uses of junction box, pull box, square box and utility box.
 
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Old 08-05-15, 03:59 PM
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When I am estimating a job I come up with a number that will cover the cost of all the parts associated to complete the task. For example:

In a house job I will figure $75 per 6" can light. Now everybody knows a can light is about $7 at the home store, so your thinking I'm ripping them off. However, now you have to figure with cable to wire each light, connectors, staples, labor, etc.

Then you will have a switch on that can light(s). Add $30 for the switch. What?! A switch is .39 cents! But again you need to add the box, cable, labor, cable to get power to the switch, etc.

So you can see how things add up and it is much simpler then counting every fitting, every screw, every bushing. This works for me, it might help you. Good luck!
 
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Old 08-05-15, 06:32 PM
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This is what I should do but unfortunately we have bill of materials. Bill of materials is a list or breakdown of electrical supplies needed for the construction for a certain project. Example, for lighting system, it was breakdown from pipe to fittings, to wires, switches and other miscellaneous materials. This is why I need some ideas in determining the quantity of fittings of the conduits.
 
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Old 08-05-15, 07:14 PM
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Your task would be simple if you were using a computer estimating software such as Accubid, McCormick or BHS. With any of these programs you just need to put in the linear feet and size of conduit with the number and size of the conductors. The computer gives you the length of conduit, number of couplings, number of supports, length of wire needed, etc. Do the same for junction boxes, etc. In addition to a material list, it also gives you the complete material cost and labor units for the work based upon the material list. You can also more easily figure your panelboards, feeders, transformers and light fixtures with this software.
 
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Old 08-05-15, 08:48 PM
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This is what I should do but unfortunately we have bill of materials
Ah, I understand now, you are coming up with the material list.
 
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Old 08-05-15, 08:48 PM
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I am using a software called Planswift but I use this only for getting the length of conduits and wires as well as the quantities of outlets, switches, etc. However, this doesn't include the fittings and boxes.

That estimating software is what I need and I have tried to search some sites about the software you said but unfortunately I cannot download it.
 
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Old 08-05-15, 08:51 PM
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Yes sir, that is why I need the quantities of conduit fittings.
 
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Old 08-06-15, 09:49 AM
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That estimating software is what I need and I have tried to search some sites about the software you said but unfortunately I cannot download it.
You can't download it, it has to be purchased along with a key for each copy you purchase. The key prevents users from copying the software to multiple computers and using it without paying for it.
 
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