Complete Overkill? You be the judge!

[peter d]

While visiting some friends at a state university in MA, I noticed they were renovating the laundry rooms in the dormitories. So being inquisitive, I had to check it out.

They were running 1 1/4" EMT to 5S boxes behind each machine. These conduits ran to a big 24x24 J box on the ceiling, and a 2" main line EMT ran into that.

So I started thinking, OK, they must be converting to electric dryers....Nope, they allready have all the outlets on the wall. Then I noticed the plans and specs were tacked to the wall:

State University Card Access System.

:roll:

 

[volt101]

Re: Complete Overkill? You be the judge!

I wish I could say that's why I hang my hat up in NH, but we use 4" conduit for a single fiber wire that is 3/8".
Jim

[ July 11, 2005, 12:00 PM: Message edited by: volt101 ]

 

[benaround]

Re: Complete Overkill? You be the judge!

Don't forget the spare 4" with pull line,just in case.

frank

 

[sandsnow]

Re: Complete Overkill? You be the judge!

I can't remeber if this is true or urban legend.

Originally the large conduits for interior came from needing to pull the cables in with the connectors already installed.

FWIW

 

[physis]

Re: Complete Overkill? You be the judge!

So being inquisitive, I had to check it out.

I don't see how you could get out of it. It's really more of an obligation.

Your tax dollars at work.

Yeah, I really hate how I have to listen to how important education is (and I completely argee it's very important) and watch the money literally be poured down the drain and have everybody crying about how education is being left out in the cold. Fire the money wasters already.

Edit: I used to do some of those access systems. I think the ones I did used stuff the size of CAT-5.

[ July 11, 2005, 06:07 PM: Message edited by: physis ]

 

[petersonra]

Re: Complete Overkill? You be the judge!

Originally posted by sandsnow:
I can't remeber if this is true or urban legend.

Originally the large conduits for interior came from needing to pull the cables in with the connectors already installed.

FWIW

I think you are right. I have had EC's pull 4" conduit for a 1/2" OD cable more than once. But the cable came with large connectors pre-installed and it was not practical to install the connector in the field.

I have also had them run larger conduit because I was afraid they would damage a cable in a smaller conduit. A cat5 cable is a lot easier to pull through a 1" conduit than a 1/2" or 3/4" conduit.

I also used to buy fiber optic cables with the ends already installed because very few electricians could make a reliable connection in the field. same with ethernet cables back when.

 

[physis]

Re: Complete Overkill? You be the judge!

I haven't put signal cable in conduit too many times so I could imagine I might be lacking some insights that come from experience, but 1 or 1 1/4 for a cat-5? That just doesn't seem anywhere near practicle or reasonable.

 

[redfish]

Re: Complete Overkill? You be the judge!

As an electrician I've pulled a few comm. cables, but how many times have I seen a comm. guy run his own conduit? NONE!

[ July 11, 2005, 07:37 PM: Message edited by: redfish ]

 

[LarryFine]

Re: Complete Overkill? You be the judge!

Originally posted by physis:
I haven't put signal cable in conduit too many times so I could imagine I might be lacking some insights that come from experience, but 1 or 1 1/4 for a cat-5? That just doesn't seem anywhere near practicle or reasonable.

Maybe there will be one cable for each student. :roll:

 

[electricmanscott]

Re: Complete Overkill? You be the judge!

Great topic. Now let's hear about what you were really checking out.

 

[mkoloj]

Re: Complete Overkill? You be the judge!

Originally posted by redfish:
As an electrician I've pulled a few comm. cables, but how many times have I seen a comm. guy run his own conduit? NONE!

Then you have never met this comm. guy.

 

[paul]

Re: Complete Overkill? You be the judge!

I wonder if it's an old spec from when they would run several #16 control wires to the C.A. systems. I've questioned some engineers on items like this before and was told it was okay to run something else, because it was from the old spec and just copied and pasted into the job.

 

[wpaul29]

Re: Complete Overkill? You be the judge!

I think you guys are forgetting something. Theres a lot more to a card access system then just 1 cat5 or something that size. There are also motion sensors for when you exit, usually there is a fail safe button just in case the motion sensor fails an then you got the door contacts wiring or the magnetic plate controls that hold the door closed plus most likely there is a intercom on the outside of the door for people who don't have normal access to the building like delivery people an all. You can also get into the part where the doors automatically close when there is a fire alarm. There are alot of variables an without looking over the print its kind of hard to judge the situation by hypothetical guesses.

 

[physis]

Re: Complete Overkill? You be the judge!

I think you guys are forgetting something. Theres a lot more to a card access system then just 1 cat5 or something that size. There are also motion sensors for when you exit, usually there is a fail safe button just in case the motion sensor fails an then you got the door contacts wiring or the magnetic plate controls that hold the door closed plus most likely there is a intercom on the outside of the door for people who don't have normal access to the building like delivery people an all. You can also get into the part where the doors automatically close when there is a fire alarm. There are alot of variables an without looking over the print its kind of hard to judge the situation by hypothetical guesses.

These things are microprocessor or computer controlled and everything is mostly multiplexed.

Edit: Not enough words again.

[ July 12, 2005, 02:27 AM: Message edited by: physis ]

 

[iwire]

Re: Complete Overkill? You be the judge!

Originally posted by physis:
These things are microprocessor or computer controlled and everything is mostly multiplexed.

They may be but I do not see that done around here. I usually see a mess of cables run by the security contractors for these doors.

I was responsible for pulling the cables and making the connections at the doors on a large job.

From a security room on each floor to each door I had to run

one - 12/2 for a motor in the panic bar or a mag lock.

four - 18/2 for various switches.

one - 18/6 for the proximity reader.

one - 18/4 for the motion sensor.

I do not know why I could not have run one 18/12 to each door but the plans called out very specific cables. :roll:

 

[physis]

Re: Complete Overkill? You be the judge!

one - 12/2 for a motor in the panic bar or a mag lock.

four - 18/2 for various switches.

one - 18/6 for the proximity reader.

one - 18/4 for the motion sensor.

It's been more than ten years since I've done one so I'll stand corrected if someone has better info than me. But that mess of cables you're talking about doesn't sound like a typical system to me. However it does sound expensive enough to install to interest most government operations.

I think the first two items could be deleted in most applications but you need a cable for the door latch solinoid.

Inch and a quarter conduit to open a door. I'm srrry, there must be something wrong. I don't know what it is, but it's something.

Have you done any with less cables than that Bob?