Ethernet cables. Shielded vs Unshielded? Make or buy made?

[Maxkling]

We use CDW as a reseller. So anything from Black Box to Tripp Lite. I prefer Tripp Lite snagless moulded.

 

[padees]

I dont think AD has Cat7 or 8

I didn't know you sold those.

Cat5e...10/100/1000... I use a lot of their 25' and 50', so I just get their shorter ones as well.

 

[geniusintraining]

Would you mind disclosing your source for pre-made cables?

I didn't know you sold those.

On second thought.... I can send you guys a free sample, of the cat7... if you like them I can start selling them, at a better price than I have listed on the site PLCTalk discount and any length you need.

I can also get Cat5 and 6, just let me know what sizes you want me to carry, the 5's and 6's are a cheaper cable, the 7's and 8's are a better quality but they cost more

 

[nocmsa]

What do most do out there in regards to ethernet cabling? Buy pre-made cable lengths for use in panels? Buy a spool and crimp your own? If you are going that route are you using shielded cabling and making cables with shielded ends on them?

I purchase a 1000 ft spool of Cat6 shielded and I have my guys make our own to exact length ( Takes 5-10 min to do), however most runs we don't shield the ends. If your building panels in bulk i suggest you buy cables pre-made.

 

[mk42]

Isn't it bad practice to have a shielded signal cable connected connected to ground on both ends?
How do you ground only one end of the shielded Ethernet cable?
Unless the device has some ground jumpers or something similar on each Ethernet port.

My understanding is that it depends a lot on the quality of your grounding. Grounding the shield at both ends is the best for noise reduction. HOWEVER, it can cause ground loops if you don't have a good stable ground level.

 

[JZerb]

Here's a part of the equation that I forgot to put in the OP. What about 600V rated patch cables? Which one would need to be UL508a compliant when using it near a VFD no? Those seem harder to come by, aside from my local AB distro.

 

[NetNathan]

Here's a part of the equation that I forgot to put in the OP. What about 600V rated patch cables? Which one would need to be UL508a compliant when using it near a VFD no? Those seem harder to come by, aside from my local AB distro.

All my communications cables are run in a separate conduit and enter the VFD alone. They do not run with the VFD cables....so you do not have to have 600V rated Ethernet cables.

 

[parky]

#1 Nathan, Even though our network contractors run bunches of network cables on existing tray or ladder rack they either ran it at least 6-8 inches from power cables or on the side away from the power. Many places I have done projects they run a separate trunking painted a particular colour or taped at distances along the length saying what it is used for. Also most have specs for cable routes etc. I'm a bit surprised that some companies do not seem to have a site specification covering everything from building fabric to electrical installation.

 

[rupej]

All my communications cables are run in a separate conduit and enter the VFD alone. They do not run with the VFD cables....so you do not have to have 600V rated Ethernet cables.

That probably works for certain VFDs. But some, like the PowerFlex 525, I've not found a clean/reliable way to separate them. Would be curious if anyone has any tricks with that.

 

[V0N_hydro]

Isn't it bad practice to have a shielded signal cable connected connected to ground on both ends?
How do you ground only one end of the shielded Ethernet cable?
Unless the device has some ground jumpers or something similar on each Ethernet port.

Hi Kallileo, I agree it is bad practice to create ground loops and multiple ground connections between different panels. I don't use the metal ethernet connectors for that reason. While we do use unshielded ethernet cable any run between panels is armoured teck so that would act as a shield in the cable tray, but within panels it is all unshielded.

 

[kamenges]

Originally posted by kallileo:

Isn't it bad practice to have a shielded signal cable connected connected to ground on both ends?

Generally speaking that is correct. However, I have never run into this as an issue with shielded Ethernet cables. I'm not sure if it is because the machines I work on are geographically small enough (usually less than 100ft cable runs) that we don't have ground plane issues or if modern industrial Ethernet devices are designed to deal with this possibility. Whatever the reason it has never caused us an issue.

Keith

 

[mk42]

I'm a bit surprised that some companies do not seem to have a site specification covering everything from building fabric to electrical installation.

It often depends on the size of the company, and how hands on management is.


I'm in MI, so automotive is the big industry. At Ford/GM/Chrysler, Do they have specifications to meet? Absolutely. But at smaller component manufacturers (say, making steering wheels or seats), the only spec is "make X parts per hour" and they often don't even have a controls person on staff at the plant.

 

[kallileo]

Generally speaking that is correct. However, I have never run into this as an issue with shielded Ethernet cables. I'm not sure if it is because the machines I work on are geographically small enough (usually less than 100ft cable runs) that we don't have ground plane issues or if modern industrial Ethernet devices are designed to deal with this possibility. Whatever the reason it has never caused us an issue.

Keith

I was working with some robotic milking equipment and the manufacturer of this robots systems always insisted to have only one end of the Ethernet cable grounded and the other end should be grounded via a 1nF capacitor using these patch panel connectors from Phoenix Contact (there is a jumper on it).
Probably this way only very frequency noise will go into the ground avoiding ground loops.
The Ethernet cables will have to be installed at least one meter away from any high voltage cables or within metal tubes.

https://www.phoenixcontact.com/onli...pcck=P-08-10-05-09&tab=1&selectedCategory=ALL

 

[Copyleft]

Isn't it bad practice to have a shielded signal cable connected connected to ground on both ends?
How do you ground only one end of the shielded Ethernet cable?
Unless the device has some ground jumpers or something similar on each Ethernet port.

https://www.cablinginstall.com/connectivity/article/16465477/grounding-shielded-cable

 

[daba]

A lot of companies don't install or specify communications cables themselves, they just employ specialist people to do the job for them, choosing a reputable company with a proven track record.

They can better advise than most, because they will do a proper survey.

If you agree to their advice, if anything goes pear-shaped, it's not gonna be at your cost to have it put right.

I've always believed in the saying "Do a job once only".