We are bidding on a commercial project whereby everything needs to be run through conduit. The client is concerned about critters chewing into the wire. There are multiple runs of AV, Data / Com, Security, Control and Cameras. The average distance for each device to the head end is approximately 200 feet. All of the cabling needs to be run off of scissor lifts because of ceiling height. The electrical contractor will be installing 1" EMT conduit for us. Is there a formula that anyone uses to caculate time requirements needed to prewire a job like this?

I have posted a dupicate of this at IP if anyone wants to comment privately. Thanks!

How many cables need to run through each conduit? Don't expect to be able to fill them and still pull the cables, especially through bends. Any HDMI cables, or just Cat5e with extenders at the ends? If you have a scrap of 1" conduit, use a bundle of scrap wire that's the same as what you need to run, to test the fit. I don't think I would use anything smaller than 1-1/2", but it's impossible to say without knowing how many cables will be in it.

were working on a large commercail space right now and are using 2" emt for all pull locations.
1" will fill up quick

1" may not be enough for all but few cables.
As far as pulling them, if you have a pull-string in the conduit, than it goes faster than pulling thru open stick construction. 
I would have sparky run and bill for all the conduits, and just bill my regular per pull cable rates.

Do as others have suggested, run 2"!!

I can't remember what size it was but it was either 3/4" PVC or 1" PVC and we were only able to pull 5 cat5e's and 2 coax in each conduit (I believe it was a 1"). If there is more than 360° in bends you are really going to struggle especailly because low voltage wires do not have a jacket good for pulling through conduits. You'll have to determine the number of wires needed and pull all of them at the same time. I think a rule of thumb would not fill the conduit with more than 75% of wire otherwise you won't make it past the first bend.

There is a calculation for electrical conductors but I don't know if there is for cat5.

Here's a chart for cat cable

[Link: cabling-design.com]

Unless your really stuffing it full,it usually takes me about the same amount of time
as it does running cable without conduit.

200' is a long pull through 1" conduit unless it's a very straight run and you only have 2-3 cat5 wires.  If there are more than three 90° sweeps, you might consider requesting a junction box in the middle to help with the pulls.

2" EMT is going to cost a fortune if you have more than a few runs and will also be logistically difficult to install around other mechanicals.

I really don't think 2" is necessary for category & coax cable and if the runs are that long, you won't be pulling HDMI through them anyway.

Can the low volt be run through plastic flex like Carlon resi-gard, or does it have to be EMT?

Here's a few photos from a job I did last summer with everything in conduit.  It's all 1" EMT with 10x10 junction boxes placed in stategic locations to help with the pulls. 







Most of these runs were less than 100ft from the junction boxes to head end or wall plate so pulling was a breeze.

I'd rather do conduit pulls like what Paul posted than do open stick wiring. A well laid out conduit design will make your life SO much easier. The junction box and sticking to smaller and more accessible/easier to work with 1" EMT will work really well.

If you have to do all the work on scissor lifts then this should be pretty quick with a smartly designed conduit system. Plan your junctions and runs and then pull away. The only time we've ever had trouble with conduit is if we try to jam too much into it (turns into a lube fest) or if someone doesn't read our spec right and puts in 3/4" (electrician usual) instead of the 1 or 1-1/4" we as k for.

PS thanks for the "official" conduit chart. I'd drawn up my own using loose end cuts of wire and a trip to HD.

Thanks for all of the replies.

The project is a horse arena and emt has to be used instead of pvc flex conduit due to potential problems with mice etc. The equipment list so far is 32 cameras, 50 zones of security, 10 audio zones, 10 data drops, 10 telco drops and 2 or 3 video zones. Telco and security will be head ended in a control room and the AV, data and cameras in an office area.
As suggested, junction boxes will be necessary because the runs will be coming from everywhere in the building.

+1 on at least 2", but we usually run 2 1/2"

Are you guys really running 2 - 2.5" EMT to all the location, or just for the main trunks to pull boxes?  These jobs really need to be thought out well and designed properly.  The main runs will need large conduit, but drops down to wall plates, speakers, alarm contacts, etc. may only need to be 1/2" or 3/4".

sorry paul.... usually multiple 1" depending what I need to the rooms, 2 1/2 main trunks to pull boxes....then drop down....I like the 2 1/2 to drop into panduit at the rack...