Cat 5e Riser Cable the Same as Cat 5e Cables?

[sumyungai]

I've done some googling about what 'Riser' Cables are and am still a little confused. Are Riser Cables the same thing as regular Cat 5e cables?

 

[ScottMac]

It is "normal" Cat5e PLUS the addition of a "strength member" - which is an additional cord added internally to the cable to reduce the stretch from the weight of hanging the cable vertically (riser = "Up an elevator shaft" or other vertical raceway).

The cord is there to help distribute the weight and reduce the strain on the jacketing ... a strength member, a strain relief.

Electrically, it is identical to Cat5e.

FWIW

Scott

 

[sumyungai]

Originally posted by: ScottMac
It is "normal" Cat5e PLUS the addition of a "strength member" - which is an additional cord added internally to the cable to reduce the stretch from the weight of hanging the cable vertically (riser = "Up an elevator shaft" or other vertical raceway).

The cord is there to help distribute the weight and reduce the strain on the jacketing ... a strength member, a strain relief.

Electrically, it is identical to Cat5e.

FWIW

Scott

Thanks, just the info I needed. 🙂

 

[cmetz]

sumyungai, riser cable meets a particular NFPA specification for not being super easy to ignite and not spreading fire too easily, that makes it acceptable for many floor-to-floor riser applications. That is, it's a fire rating, not an electrical rating.

 

[sumyungai]

Originally posted by: cmetz
sumyungai, riser cable meets a particular NFPA specification for not being super easy to ignite and not spreading fire too easily, that makes it acceptable for many floor-to-floor riser applications. That is, it's a fire rating, not an electrical rating.

I've read that PLENUM cables are of that characteristic too. So are you saying RISER and PLENUM cables are one in the same? Please correct me if I'm wrong.

 

[skyking]

My understanding of the difference:
As Scottmac said, it riser can withstand vertical runs.
Plenum has an outer jacket that does not give off toxic fumes when burned.
The term "plenum" refers to an airspace above or below an occupied area, designed to move the air for the Heating and air conditioning in a ductless manner. These spaces are commonly used for other utilities, such as plumbing and communications cabling.
If a fire breaks out, the plenum can and will conduct smoke and heat from one area to another, and the PVC jacket on standard cable will give off a poisonous gas when heated above a certain temperature.
Plenum rated cable will burn, but the outer jacket will not put off the same poisonus gas.

 

[spidey07]

Originally posted by: skyking
My understanding of the difference:
As Scottmac said, it riser can withstand vertical runs.
Plenum has an outer jacket that does not give off toxic fumes when burned.
The term "plenum" refers to an airspace above or below an occupied area, designed to move the air for the Heating and air conditioning in a ductless manner. These spaces are commonly used for other utilities, such as plumbing and communications cabling.
If a fire breaks out, the plenum can and will conduct smoke and heat from one area to another, and the PVC jacket on standard cable will give off a poisonous gas when heated above a certain temperature.
Plenum rated cable will burn, but the outer jacket will not put off the same poisonus gas.

pretty darn good description.

But now adays when you move between floors you just use fiber and avoid all the code/hassle. There are however plenum/riser requirements for fiber as well.

Generally in network design you still home every single access closets via fiber to a distribution switch for that building (or a pair for redundancy). This switch provides all the routing for that building.

In this way you avoid some of the physical and layer2 problems of network design. Each floor is its own LAN. Its own subnet.

You wouldn't believe how well this works in containing problems. It pretty much contains any kind of failure domain to a single floor - it does not disrupt the operation of "the network"

 

[sumyungai]

Good info guys. Thanks.

 

[sumyungai]

Would there be issues with network connections if I used non Riser/Plenum cable to wire a one story house with cables going through the attic?

 

[DNose]

spidey07(designed to move the air for the Heating and air conditioning in a ductless manner.)

In a home most of the time you have a duct system and most likey in the attic.

Unless you put the cable or cables in the the ducts you will be fine.
in that case you would need plenum. Do to the heat in the vents and the obvious risk.

 

[cmetz]

plenum cable is the next fire prevention code grade up. It means two things: higher ignition temperature, and does not spread fire as easily (typically because it has self-extinguishing characteristics).

My undesrstanding is once you finally get plenum cables to burn, you're getting as or more toxic fumes than riser gives off - it's just a lot harder to get there. For example, take a plenum cable and a lighter and start it burning... then all the sudden it'll go out. The process of burning the jacket releases something that helps extinguish the fire. Very cool stuff.

There was a good NEC spec around on the web somewhere that went into all the details. The executive summary is:

(least good for fire prevention)
unrated
riser
plenum
limited combustable
(most good for fire prevention)

You can always use a better fire prevention level cable where the NEC requires a lower level. So, for example, a lot of people just use plenum cable everywhere because they don't want to deal with figuring out where what kind of cable can be used, and/or don't feel like debating it with the inspector.

 

[sumyungai]

Question, how high of a wiring (wall) must be before I would need to use riser cables without a duct? I plan on wiring a one-story house from ground to attic about 14-foot tall and I won't be using a duct. Would I need riser cables for this?

 

[barney5]

In my house I have two storys, I dont have to worry to much because Cat5 is cheep and I can find and fix a cable in no time. It helps if your good at crimping the ends too.

 

[ScottMac]

Fourteen feet is nothing to worry about. "Regular" will work jus' fine.

Good Luck

Scott

 

[sswingle]

At home, I dropped a line of "regular" from the attic to the basement of a 2 story home. It was a nice handy duct that wasn't connected to anything on either end. Probably put there to heat the attic if anyone wanted to in the future. It has been wired for about 5-6 years and I have had no issues yet.

 

[RebateMonger]

re: cables in ventilation spaces.

It's probably one thing to have a single cable in a ventilation space versus putting a bundle of 100 cables in a ventilation space.......