You're the first one I've heard say to ground at a single point. You'd be surprised at the number of people who do not understand that and some don't even know grounding is required for a shield to be effective. BTW, I worked for decades as a tech in the telecom industry, as well as setting up LANs in offices. I studied Electrical Engineering in college.
@@James_Knott thank you for your reply, logically if the manufacturer has a shielded port there it means that it should be supported from the functionality that it should have. But on the other end of the stp cable there is a switch which also has shielded ports but its plug doesnt even have grounding..how that system is supposed to work there?
@@at23623 It might be or might not. That depends on the device. I have also seen equipment where the grounding is through a switch or jumper. That's why I said check the continuity. You should be able to do that with any multimeter. For example, mine has a beeper that will sound if testing for continuity. So, if you check and find both ends provide ground, then you would use an unshielded connector at one end of the STP. Normally, you'd ground at the point closest to some common point, such as an Ethernet switch.
@@James_Knott if there is the continuity and the stp is shielded in both ends but the switch is not grounded (even though it has shielded ports). Would that be ok?
I have an A/C unit that my dog chewed in 2 pieces the electrical supply cable. I didn't bother trying to repair the very thin metal bare wire and foil, because it was too difficult. The unit will not work in this condition. Is there anyway to bypass the bare wire and shield? It's hard getting to where the wires start in the unit.
Thank You RSP Supply... Briefly explanation is really helpful for us. Also this video has come in very perfect timing for me I really need such concepts in my current project. Once again Thanks and keep continue to upload such videos on Electrical & Automation Technologies.
@@RSPSupply Sir I have one doubt, that in Shielded twisted pair Cable the drain wire or (earthing of shield wire) should be earthed from one end only or it requires earthing from both end i.e, Master and Slave Ends.?? Also if possible then PL explain how ot should be earthed properly I means is it requires any specific one.!! I hope you can understand my issue and will help me definitely at the earliest... Thank you...
Hi, thank you for the video. Question: In regards to TIA-607 Telecommunications Grounding and Bonding, and especially TIA-568-C.2 Balanced Twisted-Pair Telecommunications cables, shield continuity shall be for the whole Channel which means from Comms Room Rack and Copper Patch Panel side up to the end device such as CCTV Camera. In this case, we are sending Data and Poe power to the device, including grounding from Comms Room TMGB. I understand your point, and I was wondering if you can support it with a code or a standard. Also, in the case where we have shielding connected to TMGB in Comms Room and not at the endpoint will impact the Fluke test to Category such as Cat.6 to fail. J would appreciate your insight on this.
It wasn’t clear as to where to end the grounding wire, are you saying to connect the shielding ground wire to the green ground wire of the power plug, between the neutral and hot 110V connection?
I dont understand. Is theory not the same as practice? Only ground one end of a shielded cable to for example avoid ground loops? Aren't S/UTP cables grounded at both ends on the metal part of the RJ45 jack? Then if the devices at both ends are grounded, isn't a potential for ground loop created? And how can the ground system be different if both the cable and devices are all ground together?
In theory, practice follows theory, in practice it doesn't. ;-) Actually, you have to pay attention to what you're connecting to. For example I have worked with Ethernet switches that have grounded connectors on them, which is connected to a shield ground. By using shielded plugs on the end of the cable, then the cable shield is grounded. At the other end, if the connector is not grounded, no problem. If it is, then just make sure the grounds do not connect. This can be as simple as not using a shielded plug or using an unshielded patch cord.
Theory is not always the same as practice, that’s why it’s called theory. You have to know the application and the why. Grounding is extremely complicated. We have several videos on grounding and could make dozens more. The more advanced it gets it becomes really hard to understand
Thank you for all the nice videos. I am a big fan of RSP. Are you able to produce a series about electrical drawings, how to understand different symbols and what would be the best way to follow an electrical drawing?
There are a lot of variables to take into consideration. But you are correct, shielding on both ends has become more common. I think he is off on the idea of having a protective ground buss and also a signal ground buss.
That may be OK over short distances, but not long. Even within an office, you could create a ground loop that will increase the noise. Also, you could run into differences in ground voltage (if there is power in use, you can often have significant voltage differences between ground points) which could damage equipment.
@@Liteg0 "Common knowledge" that is in fact ignorance. I've known people who didn't even know you had to ground the shield for it to be effective. Also, what distances are you talking about? Short distances, why worry, but I come from a telecom background, where distances can be significant. I used to do planning in a major central office and there the rule was ground a shield at one point only, even for cables that were run entirely within the office.
You don't often see shielded power cables. Also, the shields are not supposed to be carrying power. If you ground at both ends, it's possible to have some stray currents passing through the shield and possibly creating a hazardous situation. Even with coax, which is grounded at both ends, you have to be careful to ensure shield ground is separate from power ground. Incidentally, I used to work in telecom, where you might have signal ground, power ground, frame ground and shield ground all in the same cabinet. They were to be connected together at one and only one point, normally where the power entered the building. You can see this in homes where you have the power entrance near a solid ground with phone, cable TV and other grounds connect to that one point.
@@James_Knott I work in automation where we have a lot of big motors driven by frequency converters, those power cables need to be shielded because they generate a lot of EMI. I've read about seperating different kind of grounds and only connecting them at a single point, but never seen it been done in practice. Same with the signal cables, I've read and talked to other people who say it's supposed to only be grounded at one end, but in practice I mostly see it being grounded in both, so it's a little confusing what is the actual correct way of doing it.
@@Liteg0 I come from a telecommunications background, where shielded cables have long been used. One common example used to be DS1 "T1" lines, where you'd have shielded cables connecting the equipment. The shield grounds were grounded at the patch panel. In another note I mentioned the various grounds. Those were: 1) power ground 2) frame ground, which is all the metal cabinets, racks, etc.. 3) signal ground, typically coax, as twisted pairs don't need it 4) shield ground, for shields as described in this video, but not coax. With coax, the shield is part of the circuit, but not with twisted pairs. So, you could have all of these in a cabinet and all kept separate except at the common ground point. The problem with grounding both ends of the shield is ground loops, which can cause noise and possibly different voltages at the different grounds, though this would typically happen between buildings or within large buildings.
Litego, what’s important to remember is that you don’t go by what a talking head said on the internet, or what “we’ve always done.” You go by the manufacturers of the cables and devices instruction. It’s that simple.
OK so you state the shield ground needs to be ISOLATED FROM OTHER GROUNDING SYSTEMS. A minute later you state that the shield ground SHOULD BE TIED TO THE MASTER GROUNDING SYSTEM AT ONE POINT ONLY. Which is it please?
Thank you! A properly grounded system will serve as a protective ground just as well as it will a signal ground . You obviously don’t want to use your drain wire as a protective ground but the key is trying to keep your ground potential equal.
You have multiple ground systems which are to be joined together only at one common point. So, you have power, for which you must provide a proper power ground. You could have signal ground for some systems. If you have shielded cable, then that's another ground system. If you have cabinets and cable racks then you have frame ground. All of these must be isolated, except at the one common point that all have to connect to and that's normally where the power ground is. Even in power wiring, where a secondary building is powered from the first, the power ground or neutral is not connected to the physical ground in that secondary building. It must be separate back to the main building.
So, if you have say a 4-20ma shielded signal cable being used within a sub panel, which then feeds to a master control panel elsewhere in a building. Should the screen be grounded at any point within the sub panel? or should the grounding be left to the master control panel with the Plc in? So not grounding the shield as it enters the sub panel, but perhaps offering the option of linking it to ground if problems arise?
I’m not sure everyone would agree with the assertion that there must be an isolated ground buss just for signal ground. Then he goes on to say that the busses should be connected at one point? It’s my understanding that a properly grounded system can serve as a protective ground just as well as an ground for interference. You would want your drain wire of the shielded cable as close to the ground rod and the buss the ground rod is connected to right?
Absolutely false! Shielding should be connected at both ends of a cable. The ONLY exception to this is when a building has multiple grounding systems in place that are not PROPERLY bonded together OR you are running the cable to a different building that has a separate ground.
Not sure where my other comment went, but show me where to buy a shielded patch cable that only has a shielded metal connector on only one end? That's right, there are none, so why would you terminate your trunk cable with only one end bonded as well? You want to bond the two equipment pieces together, from the Hub to the NIC or device, regardless of how may cables are involved (one patch cable directly, OR 1 patch cable from hub to connector (patch panel), to trunk, to patch cable from device). The Hub and Device should have a fully bonded shield from point to point and be of the same potential. What this video author is suggesting is making a shielded patch cable that has one shielded metal connector on one side and one non-shielded plastic connector on the other. Does not exist and if it does, that means it's not shielded.
You're the first one I've heard say to ground at a single point. You'd be surprised at the number of people who do not understand that and some don't even know grounding is required for a shield to be effective.
BTW, I worked for decades as a tech in the telecom industry, as well as setting up LANs in offices. I studied Electrical Engineering in college.
Hello James, one question please if you know how the shielded ethernet port in a pc is grounded?
@@at23623 The way to determine that is to check for continuity to the case and also power ground.
@@James_Knott thank you for your reply, logically if the manufacturer has a shielded port there it means that it should be supported from the functionality that it should have. But on the other end of the stp cable there is a switch which also has shielded ports but its plug doesnt even have grounding..how that system is supposed to work there?
@@at23623 It might be or might not. That depends on the device. I have also seen equipment where the grounding is through a switch or jumper. That's why I said check the continuity. You should be able to do that with any multimeter. For example, mine has a beeper that will sound if testing for continuity. So, if you check and find both ends provide ground, then you would use an unshielded connector at one end of the STP. Normally, you'd ground at the point closest to some common point, such as an Ethernet switch.
@@James_Knott if there is the continuity and the stp is shielded in both ends but the switch is not grounded (even though it has shielded ports). Would that be ok?
I have an A/C unit that my dog chewed in 2 pieces the electrical supply cable. I didn't bother trying to repair the very thin metal bare wire and foil, because it was too difficult. The unit will not work in this condition. Is there anyway to bypass the bare wire and shield? It's hard getting to where the wires start in the unit.
remove the sleeving 2" further back, unravel the metal foil and twist it into a wire on both ends, join them with a wire with crimped connections.
Thank You RSP Supply...
Briefly explanation is really helpful for us. Also this video has come in very perfect timing for me I really need such concepts in my current project. Once again Thanks and keep continue to upload such videos on Electrical & Automation Technologies.
Glad to help! Appreciate your support.
@@RSPSupply Sir I have one doubt, that in Shielded twisted pair Cable the drain wire or (earthing of shield wire) should be earthed from one end only or it requires earthing from both end i.e, Master and Slave Ends.??
Also if possible then PL explain how ot should be earthed properly I means is it requires any specific one.!!
I hope you can understand my issue and will help me definitely at the earliest...
Thank you...
Hi, thank you for the video. Question: In regards to TIA-607 Telecommunications Grounding and Bonding, and especially TIA-568-C.2 Balanced Twisted-Pair Telecommunications cables, shield continuity shall be for the whole Channel which means from Comms Room Rack and Copper Patch Panel side up to the end device such as CCTV Camera. In this case, we are sending Data and Poe power to the device, including grounding from Comms Room TMGB.
I understand your point, and I was wondering if you can support it with a code or a standard.
Also, in the case where we have shielding connected to TMGB in Comms Room and not at the endpoint will impact the Fluke test to Category such as Cat.6 to fail.
J would appreciate your insight on this.
It wasn’t clear as to where to end the grounding wire, are you saying to connect the shielding ground wire to the green ground wire of the power plug, between the neutral and hot 110V connection?
thanks, very informative
You're welcome!
I dont understand. Is theory not the same as practice? Only ground one end of a shielded cable to for example avoid ground loops? Aren't S/UTP cables grounded at both ends on the metal part of the RJ45 jack? Then if the devices at both ends are grounded, isn't a potential for ground loop created? And how can the ground system be different if both the cable and devices are all ground together?
In theory, practice follows theory, in practice it doesn't. ;-)
Actually, you have to pay attention to what you're connecting to. For example I have worked with Ethernet switches that have grounded connectors on them, which is connected to a shield ground. By using shielded plugs on the end of the cable, then the cable shield is grounded. At the other end, if the connector is not grounded, no problem. If it is, then just make sure the grounds do not connect. This can be as simple as not using a shielded plug or using an unshielded patch cord.
Theory is not always the same as practice, that’s why it’s called theory. You have to know the application and the why. Grounding is extremely complicated. We have several videos on grounding and could make dozens more. The more advanced it gets it becomes really hard to understand
How do you ground a shielded wire? There's no video out there that shows you how.
Hi, did you mange to find out how to do it?
Hello ,have not grounded shielded cable same EMP effect like unshielded cable ? thanks
Thank you for all the nice videos. I am a big fan of RSP. Are you able to produce a series about electrical drawings, how to understand different symbols and what would be the best way to follow an electrical drawing?
shielding terminated at a single point is an old-class practice. Nowadays, in many scenarios, shielding shall be terminated at both ends.
There are a lot of variables to take into consideration. But you are correct, shielding on both ends has become more common. I think he is off on the idea of having a protective ground buss and also a signal ground buss.
Why? What changed?
@@Liteg0 technology.
That may be OK over short distances, but not long. Even within an office, you could create a ground loop that will increase the noise. Also, you could run into differences in ground voltage (if there is power in use, you can often have significant voltage differences between ground points) which could damage equipment.
@@Liteg0 "Common knowledge" that is in fact ignorance. I've known people who didn't even know you had to ground the shield for it to be effective. Also, what distances are you talking about? Short distances, why worry, but I come from a telecom background, where distances can be significant. I used to do planning in a major central office and there the rule was ground a shield at one point only, even for cables that were run entirely within the office.
Why is shielding for signal cables only supposed to be connected at one end, while power cables should be connected in both?
You don't often see shielded power cables. Also, the shields are not supposed to be carrying power. If you ground at both ends, it's possible to have some stray currents passing through the shield and possibly creating a hazardous situation. Even with coax, which is grounded at both ends, you have to be careful to ensure shield ground is separate from power ground. Incidentally, I used to work in telecom, where you might have signal ground, power ground, frame ground and shield ground all in the same cabinet. They were to be connected together at one and only one point, normally where the power entered the building. You can see this in homes where you have the power entrance near a solid ground with phone, cable TV and other grounds connect to that one point.
@@James_Knott I work in automation where we have a lot of big motors driven by frequency converters, those power cables need to be shielded because they generate a lot of EMI. I've read about seperating different kind of grounds and only connecting them at a single point, but never seen it been done in practice.
Same with the signal cables, I've read and talked to other people who say it's supposed to only be grounded at one end, but in practice I mostly see it being grounded in both, so it's a little confusing what is the actual correct way of doing it.
@@Liteg0 I come from a telecommunications background, where shielded cables have long been used. One common example used to be DS1 "T1" lines, where you'd have shielded cables connecting the equipment. The shield grounds were grounded at the patch panel. In another note I mentioned the various grounds. Those were:
1) power ground
2) frame ground, which is all the metal cabinets, racks, etc..
3) signal ground, typically coax, as twisted pairs don't need it
4) shield ground, for shields as described in this video, but not coax. With coax, the shield is part of the circuit, but not with twisted pairs.
So, you could have all of these in a cabinet and all kept separate except at the common ground point. The problem with grounding both ends of the shield is ground loops, which can cause noise and possibly different voltages at the different grounds, though this would typically happen between buildings or within large buildings.
Litego, what’s important to remember is that you don’t go by what a talking head said on the internet, or what “we’ve always done.” You go by the manufacturers of the cables and devices instruction. It’s that simple.
OK so you state the shield ground needs to be ISOLATED FROM OTHER GROUNDING SYSTEMS. A minute later you state that the shield ground SHOULD BE TIED TO THE MASTER GROUNDING SYSTEM AT ONE POINT ONLY. Which is it please?
Yes
@@timfop 😂😂
I came here to post the same question!
Thank you! A properly grounded system will serve as a protective ground just as well as it will a signal ground . You obviously don’t want to use your drain wire as a protective ground but the key is trying to keep your ground potential equal.
You have multiple ground systems which are to be joined together only at one common point. So, you have power, for which you must provide a proper power ground. You could have signal ground for some systems. If you have shielded cable, then that's another ground system. If you have cabinets and cable racks then you have frame ground. All of these must be isolated, except at the one common point that all have to connect to and that's normally where the power ground is. Even in power wiring, where a secondary building is powered from the first, the power ground or neutral is not connected to the physical ground in that secondary building. It must be separate back to the main building.
So, if you have say a 4-20ma shielded signal cable being used within a sub panel, which then feeds to a master control panel elsewhere in a building.
Should the screen be grounded at any point within the sub panel? or should the grounding be left to the master control panel with the Plc in?
So not grounding the shield as it enters the sub panel, but perhaps offering the option of linking it to ground if problems arise?
I’m not sure everyone would agree with the assertion that there must be an isolated ground buss just for signal ground. Then he goes on to say that the busses should be connected at one point? It’s my understanding that a properly grounded system can serve as a protective ground just as well as an ground for interference. You would want your drain wire of the shielded cable as close to the ground rod and the buss the ground rod is connected to right?
thanks!
Glad to be a first viewer 😍
Absolutely false! Shielding should be connected at both ends of a cable. The ONLY exception to this is when a building has multiple grounding systems in place that are not PROPERLY bonded together OR you are running the cable to a different building that has a separate ground.
That's not true., such bonding can negate shielding effects.
As one who has worked for decades in the telecom industry and who studied Electrical Engineering in college, I can only say nonsense.
@@James_Knott I am certainty qualified to make this assertion. What concern do you have by grounding both ends?
Sorry, you’re wrong but think you’re right. That’s okay
Not sure where my other comment went, but show me where to buy a shielded patch cable that only has a shielded metal connector on only one end? That's right, there are none, so why would you terminate your trunk cable with only one end bonded as well? You want to bond the two equipment pieces together, from the Hub to the NIC or device, regardless of how may cables are involved (one patch cable directly, OR 1 patch cable from hub to connector (patch panel), to trunk, to patch cable from device). The Hub and Device should have a fully bonded shield from point to point and be of the same potential. What this video author is suggesting is making a shielded patch cable that has one shielded metal connector on one side and one non-shielded plastic connector on the other. Does not exist and if it does, that means it's not shielded.
You guys need practical application pictorials. No one understands this.