Hi,
I need to calculate how many RG59's constitute 40% fill in a 2" conduit.

I am having trouble finding any reference for this.

I have been looking for OD dimensions but havent had much luck..

any suggestions or help is appreciated.

Mustang

I don't see where article 820 references conduit fill. I'm not sure that you are limited to 40% fill.

Mustang:
Other than doing it the 'old fashioned way (measure the diameter & do the math) I can't put my finger on anything.

Did you try the mfg????

Venturing a guesstimate.....coax is visually 'close' to #4 or #6 THHN????

John

hi,
the 40% fill requirement is a client spec..i found out that RG59 is 7/16" in diameter. THIS IS SIAMESE CABLE.
So i guess i could just do a calculation just like for a regular ckt?

This is also a combo cable with 2 #18 awg installed with the RG59.

Thanks for the replies.

Mustang

[This message has been edited by mustangelectric (edited 11-01-2004).]

RG59 is only ¼" OD.

hi,
thanks for the replies...take a look at the following document. it has some interesting information regarding rg59 conduit fill.
http://www.brownstown.com/downloads/conduit-fill_require_.pdf

i got my dimension information from here: http://www.engproducts.com/products.cfm?ID=318

Still not sure. This is a COMBO CABLE/ COAX/#18 AWG PAIR

That was the best I had found until now!

Thanks for the replies..

regards

Mustang

Mustang;


This is "Technically" known as "Siamese" or "Siamese Cable".

Installed apx. 100,000 KM of the stuff!

The PVC (CMR, Riser, etc.) type Jacketed Cable has a larger O.D. than the Plenum (CMP) type Jacketed Cable.
Also, the Plenum Rated stuff pulls through Conduits better, but costs 2× - 3× the $$$ of PVC (Riser) Cable.

Cable Manufacturers will have the O.D. displayed on their web sites.

Scott35

BTW, thanks for the links! Will check 'em out.

I am interested for the same information for Cat 5. I know I can calculate it from the tables given but I would like a chart for Cat 5 in emt if it is available.

thanks,
GJ

The 40% fill req. is more of a TIA/EIA req. rather than NEC req.

If you do tele/data, or CATV etc. you may want to check these out. They are not all of the standard in it's actual format, but seeing that the go for $200 bucks each, these trunkated versions/explanations are just fine. Also very informative.....
http://web.anixter.com/Anixter/anixter.nsf/Standards?OpenForm

--------------------------------
Just looked at them again, the pages have changed, they used to have a lot more information on them before.




[This message has been edited by e57 (edited 10-11-2004).]

Hi,
I thought the Siamese cable was a FLAT type cable with the conductors run side by side more like a UF cable?

I thought the COMBO cable was a ROUND cable assy that is more like a MULTI COND TRAY CABLE?

I am working on a project where there are a lot of video cameras. Is RG59 not an outdated cable? It seems that all I ever hear about anymore is RG6..Is RG6 more digital friendly?

Thanks for the replies..very interesting information...you never know when this type work comes along..and it helps to stay informed.

regards

Mustang

Ryan,
What is to say that the coaxial isn't a 725 installation instead of 820?
725.3(A) refers to 300.17 which can be interpreted to require Table 1 Chapter 9 fill requirements.

Mustang,
Here's a good reference for RG59 and %G6 differences. http://www.westpenn-cdt.com/pdfs/coax_train.pdf

Mustang,
RG6 is a better type of cable and it has a lower loss level at the higher frequencies than RG59.
Over here, RG6 is the only coaxial cable that is approved to be used on Satellite installations.
As a note, RG59 has an Attenuation factor of 23.3dB @ 400MHz per 300ft, whereas RG6 has an Att. factor of 13.1dB @400MHz per 300ft.
These losses get larger as the frequencies of the signal travelling through the cable. get hiher


[This message has been edited by Trumpy (edited 10-11-2004).]

Hi,
Thanks for that great link. I appreciate all the responses.

Just goes to show there is more to Coax Cable than one might have thought.

I will use this information as a reference.

Thanks

Mustang

Generally RG59 is more flexible than RG6. On a CCTV project, I specify RG59 for circuitry within an equipment rack or group of racks for ease of interconnection. Coax going out of the room (or into the room) is RG6. RG6 is better for long runs.

Good call on the 725 Ron!

If it is a 1/4" OD, I am coming up with:

27 in a 2" EMT
26 in a 2" schedule 40.

If it is a 7/16" OD, I am coming up with:

8 in a 2" EMT
8 in a 2" schedule 40.

Its amazing the difference that 3/16" of an inch makes!!!


1/4"=0.25
Pi R(sqaured)=(.125*.125)*3.14159=
.049" area.

7/16"=0.4375
Pi R(sqaured)=(.21875*.21875)*3.14159=
.150" area.


40% of 2" EMT = 1.342"
1.342"/.049"= 27.38 cables
1.342"/.150"= 8.9467 cables

40% of 2" Schedule 40=1.316"
1.316"/.049"= 26.857 cables
1.316"/.150"= 8.7733 cables

I can not imagine using RG-59 for anything other than CCTV Camera work "the copper clad type" I feel it is very outdated for any kind of CATV / SAT intallation, commercial or residential other than perhaps for interconnect / patch cable assemblies. Many are starting to feel that using RG-6 60% shield is "shorting the customer" as Quad Shield is all that is recognized by Structured Wiring manufacuters like On-Q, Leviton, Channel Plus...

Indeed. Even at mid-VHF frequencies the losses add up rather quickly on long runs.

The taxi place I've been developing the software for are running about 300 ft. of tatty old RG58 on their base radio at the moment (high-band PMR, around 150MHz) and the signal and range are terrible. I've been trying to convince them to have the antenna moved closer and to replace the cable with something more suitable.

Hi,
I appreciate the calculation. Your right it is VERY amazing that there would be such a reduction for a mere 3/16"!

Can you MIX RG59 and RG6?

Do these cables connect to a interface at the JB from the cameras or do they continue on back to the main board?

I am interested to know how they connect as well. This is for a closed circuit tv installed for observation at large refueling stations across the country.

Thanks again for the great replies, this has been a LOT of help!

-regards

Mustang

go to http://bwccat.belden.com/ecat/jsp/Index.jsp

Rowdy

Paul,
Whoa!.
Couldn't they get the aerial any closer?.
I'd be getting the thing up on the roof and as high as possible, with a good run of RG-8 or even BELDEN 9913 and doing a decent SWR test on the installation.
Mustang,
It doesn't pay to inter-mix coax cables, it's like having a length of #12 spliced into a #10 electrical cable.
Also, I'm not sure that you can get crimp connectors (the most reliable) for RG-59.
About the cameras, the coaxial cables AFAIK run back to a controller, where a monitor and Time-Lapse Recorder are placed.
The cameras depending upon brand, use a Female BNC connector to connect to the coaxial cable.
Hope this helps.

{Message edited to remove typo's}

[This message has been edited by Trumpy (edited 10-12-2004).]

Hi,
Still not finding any dimensions on Siamese cable...RG59/2 #18 AWG..

Any ideas?

Thanks

mustang

[This message has been edited by mustangelectric (edited 10-12-2004).]

You're very welcome

Many are starting to feel that using RG-6 60% shield is "shorting the customer" as Quad Shield is all that is recognized by Structured Wiring manufacuters like On-Q, Leviton, Channel Plus...

Arrrf! Those idiots will specify anything without a real reason.

RG-6 with a bonded foil under a 60% braid is fine for almost all installations. Only time you may want to use something with more shielding (and that is not necessarily "quad shield") is if you have RF ingress problems- and you would probably have to be next to a high power transmitter of the right frequency to have them.

Keep in mind that all cables of a type will exhibit the same attenuation. This means that, for instance, all RG-6 size cables with a foam dielectric will all have the same attenuation and regardless of the shielding. So using a "quad shield" cable will only cost you more money and make installation more difficult because it is larger and less flexible.

Notice also that I said RG-* size cables. That's because the actual RG cables have a solid dielectric, solid copper center conductor and a copper braid shield. Though these are still available (preferred for video applications) the cables we generally use are not RG design at all and only maintain the original sizes- 59, 6 and 11.

... On a CCTV project, I specify RG59 for circuitry within an equipment rack or group of racks for ease of interconnection. Coax going out of the room (or into the room) is RG6. RG6 is better for long runs.

Unless your runs are VERY long RG-59 size cable is fine. This is because video will never exceed 6Mhz and the attenuation in that range is low even for RG-59.

CATV which can go to 750 or 1000Mhz and satellite which goes to 1450Mhz requires a lower loss cable to be able to run it any distance.

-Hal

[This message has been edited by hbiss (edited 10-12-2004).]