Cat5 RJ-45

Todd0x1

Senior Member
Location
CA
Jack on the end of the cable and a patch cord wherever possible though I admit sometimes that's not possible.



Aside from the wiring standard 568A and B, almost nobody knows that there are different plugs for solid and stranded wire . Use the wrong one and you are guaranteed to have intermittent problems. And stranded wire is for patch cords, not building wiring. Yeah, I know, you can get it real cheap on eBay. That's why.

So let's see, you have bozos who have no idea how to wire plugs then you have people who have no idea what plug to use. Yup. better off with a factory patch cord from a jack that any idiot should be able to install on the end of a cable.

-Hal

Am I allowed to field crimp RJ45 plugs?
20200227_215739-1200.jpg
 

oldsparky52

Senior Member
Am I allowed to field crimp RJ45 plugs?
View attachment 2555321
Okay by me! BTW, looks good.

I'm curious, do you have a cable tester and do you test your cables after installing? I only installed these at home back in the late 90's/2000. I didn't purchase a tester and ... the internet worked great! :)

I know the pump and tank techs would not install any cables that didn't come with factory ends.
 

rnatalie

Senior Member
Location
Catawba, NC
Occupation
Retired Electrical Engineer
Dr. Fine is correct. The only difference between A and B are the colors. Electrically they are identical. As long as you get the pairing right and maintain the twists, everything you can run over Cat5E that I know of will work.

The paring is 1-2, 3-6, 4-5, 7-8. The reason the center two pair (3-6, 4-5) is to make them compatible with the old RJ-11 plugs (you can actually stick an RJ-11 plug into the center of the RJ-45). The primary phone pair were on the center two and the line2 if you had it were on the outer.
they decided not to continue that (putting the next pair on 2-7) so as not to space out the pair wires too much, in my opinion.

Note that RJ-45 has been around a long time. Much longer than Ethernet (even before coax ethernet). The phone company used it for interfacing CSUs to the phone system.

Crimping male plugs requires a decent tool in good condition. It's slightly more of an art than pushing down wires into the jacks (either with a 110punchdown tool or a device that terminates all 8 wires at one time).
 

hbiss

EC, Westchester, New York NEC: 2014
Location
Hawthorne, New York NEC: 2014
Occupation
EC
Note that RJ-45 has been around a long time. Much longer than Ethernet (even before coax ethernet). The phone company used it for interfacing CSUs to the phone system.

The 8Pin/8position plug and jack has had many uses. The RJ designations came about in 1968 because of the phone company divestiture which allowed self installation. Most notably the phone company (actually AT&T) used the 8Pin/8position plug and jack for the old Merlin phone systems with 4 pair Cat 3. They were wired 568B and is probably why that standard (the Western Electric standard) became so popular.

The only difference between 568A and 568B is that the orange and green pairs are swapped. Doing so put the second or orange pair on pins 3&6 making the wiring and jack compatible with 2 line POTS jacks should it ever be needed to be used for that. In those days modems and faxes were in regular use.

I'm curious, do you have a cable tester and do you test your cables after installing? I only installed these at home back in the late 90's/2000. I didn't purchase a tester and ... the internet worked great!

If you wired a receptacle with the hot and neutral reversed wouldn't it still work? Just because it works is only a step above it not working. There is a high probability that a field installed plug will not work or is wired incorrectly yet will work. So unless you want to go back to a job because the customer is complaining that something isn't working right, the minimum testing you should do is wire mapping with an inexpensive tester. This will show that all 4 pairs on the plugs and/or jacks are wired correctly and have continuity. So you can leave the job with confidence knowing that all your wiring is correct and working. Then if the customer complains you can tell them that your wiring was tested when you left the job so it must be something else.

-Hal
 

LarryFine

Master Electrician Electric Contractor Richmond VA
Location
Henrico County, VA
Occupation
Electrical Contractor
Note that RJ-45 has been around a long time. Much longer than Ethernet (even before coax ethernet). The phone company used it for interfacing CSUs to the phone system.
Alarm companies also used them in line-seizure wiring, so lifting phone handsets wouldn't stop dialers from dialing.
 

texie

Senior Member
Location
Fort Collins, Colorado
Occupation
Electrician, Contractor, Inspector
FWIW, the TIA standard used to not allow putting ends on horizonal cabling infrastructure. All cables were required to terminate in a jack. Then with the proliferation of IP cameras, WiFi access points it became apparent that a jack and patch cord was not the way to go for things like this
I like the new style RJ-45s that are "pass thru" like the Platinum Tools plugs and tooling. See them here: https://www.platinumtools.com/produ...rs/ezex-38-ezex-rj45-cat5e-connector-100047c/
 
Jack on the end of the cable and a patch cord wherever possible though I admit sometimes that's not possible.



Aside from the wiring standard 568A and B, almost nobody knows that there are different plugs for solid and stranded wire . Use the wrong one and you are guaranteed to have intermittent problems. And stranded wire is for patch cords, not building wiring. Yeah, I know, you can get it real cheap on eBay. That's why.

So let's see, you have bozos who have no idea how to wire plugs then you have people who have no idea what plug to use. Yup. better off with a factory patch cord from a jack that any idiot should be able to install on the end of a cable.

-Hal

I think you need to train your employees better if this is an issue.
 

MD Automation

Senior Member
Location
Maryland
Occupation
Engineer
Note that RJ-45 has been around a long time. Much longer than Ethernet (even before coax ethernet).

Yes, there is even a standard CAN bus interface for the RJ-45. Most people just see that 8 pin jack and say…Ethernet!

A ton of my work for the last 15 years has involved the CAN bus as a communication (fieldbus) interface. I will admit that I was surprised the first time I saw the RJ-45 used as a CAN port on some sort modules inside a large carousel. I am not a big fan of it as a physical CAN connection, but nothing I could do about it except learn to work with it.
 

tortuga

Code Historian
Location
Oregon
Occupation
Electrical Design
Yes, there is even a standard CAN bus interface for the RJ-45. Most people just see that 8 pin jack and say…Ethernet!

A ton of my work for the last 15 years has involved the CAN bus as a communication (fieldbus) interface. I will admit that I was surprised the first time I saw the RJ-45 used as a CAN port on some sort modules inside a large carousel. I am not a big fan of it as a physical CAN connection, but nothing I could do about it except learn to work with it.
Yeah I hate that, does the can bus even use more than 4 pairs?
 

MD Automation

Senior Member
Location
Maryland
Occupation
Engineer
The CAN bus itself uses only a single twisted pair - CAN Hi and CAN Low, typically also has a shield/gnd. It's also common to find a CAN cable with another pair for 24V Logic Power.
 

Todd0x1

Senior Member
Location
CA
The CAN bus itself uses only a single twisted pair - CAN Hi and CAN Low, typically also has a shield/gnd. It's also common to find a CAN cable with another pair for 24V Logic Power.

I was helping one of those high school robotics teams. Their whole control system uses CAN bus. Couldn't find any small wire for CAN we liked so I had some made. Took rolls of yellow and green 22ga XLPE insulation AWM wire to a processing place that did a planetary twist to it. That worked out nice.
 

MD Automation

Senior Member
Location
Maryland
Occupation
Engineer
I was helping one of those high school robotics teams. Their whole control system uses CAN bus. Couldn't find any small wire for CAN we liked so I had some made. Took rolls of yellow and green 22ga XLPE insulation AWM wire to a processing place that did a planetary twist to it. That worked out nice.

Cool that you made your own cables! Certainly not going to stumble across CAN cabling at Home Depot.

At the risk of de-railing this thread, and boring you all to sleep on a Saturday night, I have a lot of spare cabling within 10 feet of me, so...

This is a simple 2 conductor CAN cable with shield and a standard Ethernet cable above it for comparison. It's a pair of 22 ga wires and we get this from LAPP Kable (Germany). By spec, CAN cabling has unusually thick insulation. The OD of each CAN wire in this photo is ~ 0.080" compared to the 0.038" of the Cat5e. Some of that is the Ethernet wire is a bit smaller (24 ga), but the insulation is really the biggest difference in size.

1K8A7792_1.JPG

Here is a pic of another type of CAN cable that contains a pair of 16 ga (Red / Blk) conductors used to carry (typically) 24 VDC Logic Power to fieldbus devices. The Blue and White wires are CAN and the small bare wire is the shield drain. In this picture you can also see some different sized molded 5 pin connectors, these were made for us by Turck.

1K8A7793_1.JPG

Lastly, I tried to get a picture to illustrate the difference between insulation thickness. The Red wire is for 16 ga DC Power and the Blue wire is a much smaller 22 ga but with so much more insulation it ends up bigger than the #16.

1K8A7868T_1.jpg

These large wire thicknesses are one of the reasons I dislike the RJ45 CAN connector, that Blue wire will never fit into a standard RJ45 slot, they are designed for much smaller conductors. It's even sometimes a problem to find a good ferrule or pin to crimp onto wires like this, because the copper wire inside (#22) is so small compared to the OD of the wire plus insulation. They make some really interesting cables nowadays to solve problems like this that have 2 layers of insulation around the copper wire, the inner insulation is smaller and there is a larger (some type of foamed fluoropolymer) used to make a second outer layer that can be removed separately at termination points.

I've never seen that special cable in person and it's also not in any Home Depot aisle ;)
 
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tortuga

Code Historian
Location
Oregon
Occupation
Electrical Design
Cool that you made your own cables! Certainly not going to stumble across CAN cabling at Home Depot.

At the risk of de-railing this thread, and boring you all to sleep on a Saturday night, I have a lot of spare cabling within 10 feet of me, so...

This is a simple 2 conductor CAN cable with shield and a standard Ethernet cable above it for comparison. It's a pair of 22 ga wires and we get this from LAPP Kable (Germany). By spec, CAN cabling has unusually thick insulation. The OD of each CAN wire in this photo is ~ 0.080" compared to the 0.038" of the Cat5e. Some of that is the Ethernet wire is a bit smaller (24 ga), but the insulation is really the biggest difference in size.

View attachment 2555437

Here is a pic of another type of CAN cable that contains a pair of 16 ga (Red / Blk) conductors used to carry (typically) 24 VDC Logic Power to fieldbus devices. The Blue and White wires are CAN and the small bare wire is the shield drain. In this picture you can also see some different sized molded 5 pin connectors, these were made for us by Turck.

View attachment 2555438

Lastly, I tried to get a picture to illustrate the difference between insulation thickness. The Red wire is for 16 ga DC Power and the Blue wire is a much smaller 22 ga but with so much more insulation it ends up bigger than the #16.

View attachment 2555439

These large wire thicknesses are one of the reasons I dislike the RJ45 CAN connector, that Blue wire will never fit into a standard RJ45 slot, they are designed for much smaller conductors. It's even sometimes a problem to find a good ferrule or pin to crimp onto wires like this, because the copper wire inside (#22) is so small compared to the OD of the wire plus insulation. They make some really interesting cables nowadays to solve problems like this that have 2 layers of insulation around the copper wire, the inner insulation is smaller and there is a larger (some type of foamed fluoropolymer) used to make a second outer layer that can be removed separately at termination points.

I've never seen that special cable in person and it's also not in any Home Depot aisle ;)
Thanks yeah I remember working with that stuff, i meant to say two pairs (4 wire) in my last post, seems like a regular RJ25 POTS jack would be better, but that DIN connector is best.
 

klillemo

Member
Location
Twin Cities, MN
I’ve noticed the brown pair is not twisted as tight as the rest. I brought this up to a Leviton data wiring trainer, and he said it shouldn’t be, but I’ve noticed it on several brands.

Each of the 4 colored pairs has a different twist rate to avoid cross talk between the pairs. That is a network cable design requirement.
 

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
Each of the 4 colored pairs has a different twist rate to avoid cross talk between the pairs. That is a network cable design requirement.
And the standard does not appear to specify what the twist rate is for any particular pair. So it could well be different for different brands of cable.
 

hbiss

EC, Westchester, New York NEC: 2014
Location
Hawthorne, New York NEC: 2014
Occupation
EC
And the standard does not appear to specify what the twist rate is for any particular pair. So it could well be different for different brands of cable.

That's absolutely true. Each manufacturer has a different design, even between the same cable but different listings (like plenum and riser for instance).

-Hal
 
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