First off, I'm not an electrician. I am an electronic technician that works with commercial fire alarm systems.

I can't say with 100% certainty that you don't need shielded cat5 in your situation, because I'm kind of comparing apples and oranges. However, On all of our systems, all network wire is required to be shielded, UNLESS it is run in EMT.

Unless you can get the engineer to sign off on it I would use the sheilded. If you don't use it and the system doesn't work, they are going to point to you and the cable and make you replace it.

sensitive systems require the extra measure...the architect that is calling for cat 5 in conduit,I feel is doing a good job.My work has controls for energy management systems,all cat 5,all in conduit.the shielded in conduit is the way to go..

shielded cat 5 is not much more cost than unshielded, so do it how they ask. we install WISPs and have to use shielded for many apps. it just won't work without the shield. some video multiplexers require the shield so that they don't mess with each other, especially when using multiple runs inthe same place.

I worked for an insurance company (Doing tech support) and they had the token ring cables replaced with cat 5, trouble was the people doing it used unshielded cable and ran it parallel to the power cables under floor. I don't know why they never had the contractor come back and make it right but we never could get it to work at 100mb, it would work at 10mb. It would have been better to just keep the 16mb token ring. Like another person said, the cost is not much more for shielded cable and it always sucks to have to do something twice. So in addition to using shielded cable, do not run it parallel to any power cables (You can cross them no problem).

Static

The two things pertaining to this installation are the technical/performance issue and the specifications for this installation. I am not an expert on the technical/performance aspects involved. But so long as the specifications do not conflict with applicable codes, the contractor is responsible to comply with those specifications.

thanks for the info. The architect did not spec emt for technical reasons. It was all cosmetics. The original plan was for converters that did not require shielded cat5. The converter they would like to use instead does spec shielded. so sense the wire happens to be in emt, would it accomplish the same thing? This is a very relaxed job, the architect scribled the plan on notebook paper and could care less what wire was ran. The emt is because the wire is surface mounted on a concrete wall. Think it would work or would the cables need shielding from each other? Thanks!

What problem could possibly arise from using the shielded cable? Your answer to that question will indicate which cable you should use.

It's not a matter of what to install the cat 5 was already pulled. It's the change over from the previous device that I don't know will work with the current cat5.

Answer this question and you will have your answer.
How much will it cost replace all the cable and reconnect everything if the current cable doesn't work? Can you afford to install the system twice? Once to test the current cable and once to replace it all maybe 6 months from now when you can't figure out why strange things are happening on the system?

Or use the original devices that they said would be used and not bother with the equipment that calls for shielded cat 5. If they need shielded cat5, it's their dime to replace it. This is literally a, "Hey do you think we could use this model of video converter instead of the one we were originally going to use" Me, "Probably so, I will check the specs on it to see if the wiring that is already installed can support it" I just don't know whether to tell them it can be used or if it is the type of situation where there is no way to know if things would work correctly (using the emt as shielding).