Low-Voltage Q&A With Don and Dave

We often get asked questions through email, live chat, social media, and over the phone. A lot of times these are commonly asked questions about the low-voltage industry that many of our customers want an answer to. We decided to take them all and throw them at Don and Dave, not literally, to see what they had to say! So stick around, you might be able to learn a thing or two! 

Mikayla: Hey, everybody. My name's Mikayla. I work here at trueCABLE, on our marketing team. Today we're going to go over some customer questions and put Don and Dave to the test.

Don: I'm Don, and by now, you might know me because I have been doing a lot of technical videos for YouTube and putting out blogs on our website in our cable academy. I've been with trueCABLE for three years. I'm a technical manager and my responsibilities are quality, product design and development, and also content, like the video that you're watching right now, YouTube, the blogs, etc., etc..

And we recently hired in someone to augment me and add a new dimension to trueCABLE, and that would be Dave Harris.

Dave: Hi.

Mikayla: Our first customer question for today is: Are load bar or pass through RJ45’s better?

Dave: Load bar.

Don: Yeah, I would say load bar, especially when it comes to Cat6A. Like we have a stagger RJ45 plug that's a so-called standard plug in solid nose, but it uses a load bar and the load bar is position sensitive, it's green colored and it does stagger the conductors and with Cat6A specifically if you're running it to see if you want to certify it to Cat6A and you're actually trying to push it to 10 gigabit, that greatly reduces crosstalk at the connector. As I have found out, it has no impact at all. The stagger load bar style plug has no impact performance wise on Cat6 or Cat5e. And I've proven that with the Fluke DSX-8000 as well. So I would say pass though RJ45s have their place. I would restrict the use of pass throughs to Cat6 and Cat5e. Make sure they're well fit and make sure you're using them sparingly and not try to make your own patch cords.

If you need to terminate solid copper Cat6A and you have no alternative but to put on a RJ45, then the load bar plug is your best bet.

Mikayla: Is it okay to make my own patch cables?

Don: No. You should buy factory pre-made, pre terminated patch cords. Especially if you're making patch cords from solid copper Ethernet. Let me subdivide that answer. It's a little more complicated than it sounds. If you're using stranded copper Ethernet, and that would mean the conductor is stranded not solid, you've got the proper fitting RJ45 plug and you're willing to test your patch cables to make sure they actually work, then sure. Go for it. If, on the other hand, you are making patch cords from a solid copper Ethernet and you want to use RJ45s, that is probably the least best way of going about it. If you want to make a patch cord that actually works and it's a critical application, then I would strongly recommend field termination plugs, not RJ45s. It has to do with the fact that no matter how well we control the tolerances on our Ethernet cable insulated conductor, eventually you're going to get one or maybe even a run of them, where they're not going to fit just perfectly to perform to your expectations.

Mikayla: Why does trueCABLE focus on compatibility and selling items together as a system?

Don: The thing is, is a lot of people don't understand that a Category 6 plug is not really a Category 6 plug. RJ45 plugs, 8P8C plugs, things like that, they don't really have a category. It's just a piece of plastic with 8 golden contacts. So it's all about fitment. When we're talking about compatibility, we're talking about the fitment, and you need to take all of your tools, your plugs, your cable and make sure everything works well together so that when you come to trueCABLE as a one stop shop, you're getting a much greater possibility of a working installation off the start line.

Nothing is more frustrating than buying a bunch of different components from a bunch of different manufacturers and finding out that there is some sort of nuance there that prevents you from doing what you want to do or getting a performance you want to get.

Dave: And you'll find this is true of all cable manufacturers, and you can't mix and match because like Don said, it's all about fitment. It's not about category. You can get Category 5e cable that's 22 gauge. You can get Category 5e cable, that's 24 gauge. The RJ45 for one will not fit the other. So it's not enough to say that this is a Cat5e cable or connector.

Mikayla: Is there a difference between Ethernet and Internet?

Dave: Ethernet is a protocol that you run between your devices and your network. The Internet is the network outside your local network, often called a wide area network. Ethernet is a protocol for accessing the Internet. That might be a good way to put it.

Don: The way I like to characterize it, to help really bring it home to people and helps some visualize it, is Ethernet cable is used for local area networks. That is a site, a building, a house or something along those lines. Internet is what's known as a wide area network. It's a perfect example. There's multiple kinds of wide area networks. The Internet is probably the penultimate example of a wide area network because it is basically the definition of a WAN or a wide area network. It is a conglomeration of many different LANS that can somehow all communicate with each other in some fashion.

You can have a local area network, a LAN, while using Ethernet cable and Wi-Fi, and have no access to the internet, which is another network that's the WAN side. So you have no access out through a gateway, but you need to do file sharing and other activities inside your business. But you don't want people getting information out on the Internet. A good example of where that would be used is a U.S. military installation.

To learn more about the different types of networks check out WAN vs. LAN: What Is the Difference?

Mikayla: What is low-voltage wire commonly used for?

Don: Low voltage wire is commonly used for data communication, alarm, fire alarm controls, security systems, and IP cameras. In other words, anything that is considered AC, 120 volts or higher branch circuit, is considered to be high voltage, according to the National Electric Code. Anything that's operating under that is considered to be in the low-voltage category.

Mikayla: Can I use unshielded terminations on shielded cable?

Don: Only if you want trouble. I mean, if you get it to fit right, it'll work. It'll seem to work, but you're setting yourself up for potential issues. The biggest being that if you have a shielded cable and you're using unshielded terminations on both ends, there's no way for that cable shield to bond and then drain off to ground.

Therefore the cable shield may actually pick up and induce interference on your cable pairs as opposed to mitigate them. And the reason why that is, is because the cable shield is a channel down to ground. You're talking about thin foil shielding inside of a cable that's not going to block really, really high EMI.

What it does is it channels it down that's used as a path, not a block. Another reason you would get yourself into trouble with that would be electrostatic discharge if you need to drain off electrostatic discharge, there is no path for that to occur. So a lightning strike could cause more damage than it should. Or you may not have any damage at all had you not done it properly.

Dave: And an ungrounded shielded cable is a big antenna.

Don: Yes, they can function as an antenna.

Dave: It will actually attract EMI. And if you asked the reverse, can you use a shielded ends on unshielded cable? Well, it'll work. But then you've got an unshielded cable that looks like a shielded cable because it's got shielded ends on it and people are likely to misidentify it in the future.

Don: So it's technically bad form.

Dave: Right.

Mikayla: Is shielded Ethernet cable better to use?

Don: Shielded ethernet cable has its place. The answer is no and yes at the same time. First of all, a lot of people misunderstand shielding and what it is used for and the perception around shielding. So a lot of people buy shielded cable thinking, oh, it's shielded. I mean, this must be better, faster, stronger. The fact is, is shielding can actually introduce far more trouble into your network than if you didn't use it at all.

Cable shield is designed to mitigate factors such as electromagnetic interference, that being from high voltage motors or AC brand circuits that are running in your walls and other factors like that. The shielding is designed to head off an issue from occurring. In of itself, shielding does not increase performance.

Mikayla: If everything is connected to Wi-Fi, why do we need Ethernet cable?

Dave: A direct connection or wired connection to your Ethernet network is more secure and it's faster.

Don: Don't use Wi-Fi unless you've really got no other alternative. For example smartphones, laptops, and tablets. Things that you have no ability to plug in. However, if it's feasible and reasonable to plug it in, you should be plugging it in. If it's something that is critical, high reliability needs a connection that's stable at all times, plug it in.

The reason being that Wi-Fi is highly susceptible. There's two frequency spectrums that are being used 2.4 gigahertz and 5 gigahertz for Wi-Fi. Now, 5 gigahertz does not have as much interference on it, although that's changing. But the problem with 5 gigahertz is as clear air as it is, it's got a shorter range and very poor object penetration, especially concrete, glass, and things like that.

So it may give you higher speed, but it's going to give you greatly reduced range. 2.4 gigahertz, on the other hand, can go through at least one concrete wall and it gives you a much better range, but it's lower speed and it's far more susceptible to interference because it actually only operates on three discrete channels. Even though you see channels 1 through 11, it's not really 1 through 11. I mean, I suppose you could call it 1 through 11, but the real discrete channels are 1, 6, and 11 and everything else is sharing those bandwidths with some of the other channels.

So you're going to get a congested network real quick. Not only do you have interference from your neighbor's network, but you're susceptible to a badly behaved microwave oven, you're susceptible to a baby monitor, to a garage door opener or something else that's misbehaved. I have seen entire Wi-Fi installations brought down by somebody who bought a cheap microwave from some big box store, I won't name. Then turned it on and everything came to a screeching halt while the microwave was on and everything was fine right after the microwave got turned off.

Reliability is your primary concern when it comes to using Ethernet over Wi-Fi, speed is a close second, and security is a close third. Security is not as much of a issue anymore because of newer Wi-Fi protected access protocols like WPA3. 

But when it comes to networking, Ethernet or basically wiring, whether it's fiber or copper is king and always will be king.

Mikayla: What is the difference between trueCABLE’s small and large cut-to-fit strain relief boots?

Don: If you look at them side by side, you're like, I have no idea what the difference is between these guys. What it has to do with is not the size of the strain relief boot itself, but it has to do with the vertical height of these locking bars that go in to the back of RJ45 plugs. 

The difference is, the small cut to fit boot takes the same cable overall diameters as the large cut to fit, but these locking bars here actually fit inside the so-called Cat5e plug, physically speaking. So this would be a loose fit. And our so-called Cat6 pass through plugs or Cat6/6A load bar plugs where the large cut to fit won't fit into our so-called Cat5e plug at all.

It has to do with the fact that the bars back here are too big vertically. It won't go in all the way. So it's either a really tight fit or it won't actually go in. That's essentially the difference, the height of the bars. And if I could get a close up photo for you here, you'd see it's a very small, almost imperceptible difference, but it's about half a millimeter. That's about the difference. It has to do with the rear entry into the plug itself.

Mikayla: When terminating my Ethernet cable, should I use a field termination plug or a RJ45 connector?

Dave: If you're using Cat6A and you need an RJ45 plug on the end of it, the field term plug is your best choice because it has circuitry in there to make sure that there are no differences in impedance in the channel. Best way to say that is its impedance matched to the cable. A plastic RJ45 connector doesn't do that, so you get better performance with a field termination plug and it's more likely to certify at Cat6A.

Don: There are certain situations where you might have to use a RJ45. I'll give you a good example. Here at our installation of our warehouse, we have a number of MPTL or modular plug terminated links. They are 270 feet long. They were d rated according to maximum possible temperature they might be exposed to out in the warehouse.

So they're running from a keystone jack patch panel and they're running up and over and out and then they're terminating to load bar RJ45s and that's Cat6AA cable. Now those runs certify, even though I'm using an RJ45, but the plug is properly fit and I'm using a load bar plug and it's certified and I know it works.

A field termination plug takes a lot of the fitment problems out of the equation. RJ45s are notoriously problematic when it comes to fitment onto solid copper Ethernet cable and also not just fitment issues, but just reliability, mechanical reliability. They're not very stable mechanically, so if it's not perfect, you can't get it perfect, or if you can't find the right plug use a field termination plug. That's going to give you the best performance every time.

Mikayla: Is your most expensive cable also your best cable?

For us that would be Cat6A Plenum Shielded.

Dave: No, you only need plenum Ethernet cable if you have a certain installation requirement. If you are pulling your cable above a suspended ceiling, which is a plenum space, you need to use plenum Ethernet cable. In most cases, if you're pulling through a cold air return or some kind of other HVAC, you have to use plenum because of the characteristics that it has during a fire and the products that it puts off when it burns.

So plenum is more expensive because it takes special materials to make sure that it meets those qualifications.

Don: Half the weight of a plenum cable jacket is teflon, micronized teflon.

Mikayla: What kind of cable do I use for HDBaseT?

Don: Basically, it is a protocol it's not a cable. And I believe the HDBaseT Alliance recommended at least Cat6, and I think they're giving a preference to Cat6A. I think they even throw shielded in there for some unknown reason that I don't necessarily agree with, but I believe any Ethernet cable that passes category certification that's Cat6 or higher is going to be more than enough for HDBaseT.

More than enough.

Mikayla: Live Question from TikTok: So could you expand on why you’d use T568A vs T568B vs USOC?

Don: USOC isn't used for networking. USOC is an old standard that was used for previous application protocols and technologies. T568A and T568B are the only two approved color code standards for modern data networking. There is no discernible advantage of T568A or B, and I've tested it that way. I've done a fluke test with an identical cable, identical jacks, identical date, identical cable length, identical temperature, terminated both ends to A and then I ran the test and I terminated both ends to B and BAM.

It was the same performance. So there's no advantage in performance as long as you're wiring it A to A or B to B in your modern data network, you have no issues. Proceed as you like.

Dave: The main thing is to stay consistent within your installation, use the same one everywhere. And having said that, i've worked a lot of installation jobs over the years and I have not had a single customer specify T568A so I won't say that it's getting to be an industry standard, but....

Don: B is the de facto standard nowadays.

Dave: I guess, and I'll say it again, over the last ten or so years, I have done new installs in many government buildings, many military installations and many brand new schools. And I have never had someone specify T568A.

Mikayla: And that's a wrap for today's Q&A with Don and Dave. Comment below some more questions so we can put them to the test again next time!

HAPPY NETWORKING!!
 

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