Omada EAP power supply issues

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Omada EAP power supply issues

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Re:Omada EAP power supply issues
2022-03-03 17:40:10

  @JasonHogan 

Even this is not from TP-LINK. But, quite informative. CAT6 is likely to have an issue. Tested with CAT5E?

 

Forum title:

Unexpected PoE / Cable length limitations with UniFi Switch-16-150W & UniFi AC-LR Access Points

Post: 

What you are likely seeing here is something that will become more of a problem down the road - CAT6/6A cables are being made with 26 gauge cable.

 

The biggest problem with 10Gb ethernet is crosstalk between the wires/pairs in the cable.   THere's just one way to lessen this - move the wires physically farther apart.   One way the cable mfgrs have found to accomplish this while not making the cable too large - there is actually a spec for the maximum diameter of ethernet cable - is to make the copper wire itself smaller, so the insulation is thicker, so there's more space between conductors.   This actually works ( and they love it because there's less copper which saves them money, but they can charge more for the cable because, well, it's spec'd higher, right?) , but it causes the problem you are seeing - the smaller conductor has higher resistance and therefore more voltage drop than the standard cat5e 24 gauge wire.   So with longer cat6 cables ther PoE limitation needs to be accounted for.   This is why I never use Cat6/6A cables except for very specific things, and never ever for PoE.

 

Change out your cable to cat5e and the problems will go away.   And at gigabit speeds it will work just fine up to 100 meters, even at 24V PoE.

Jim

ScReW yOu gUyS. I aM GOinG hoMe. —————————————————————— For heaven's sake, can you write and describe your issue based on plain fact, common logic and a methodologic approach? Appreciate it.
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#12
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Re:Omada EAP power supply issues
2022-03-03 18:01:28 - last edited 2022-03-03 18:01:58

@Tedd404  I disagree with few things, for one it would be false claim that cat6e should not be used with poe+ or that it does not work, thousands households where it works since over 10 years would disagree with you. The biggest issue in cable choice is not really if it is cat5/cat6, many people fall for cheap cables where no 100% cooper is used but some aluminium with cooper just around it. Cable quality matters. Those cables one does not want to use at all, for nothing, maybe for hanging things around in a room or to fix it, but not for networking. Those aluminium cables can cause fire too and should never be used with PoE, and that has nothing to do with how thick cables are.

 

As next, if one crimps cables, there a lot can go wrong, starting with material usage and finishing with technical skills of a user.

 

Also, there are different cables for different purpose, as example those which you put inside a building can break if you push it over 90°. Then normal user buys such super expensive cables and breaks them during laying, resulting in going back to lets say not solid cooper cable.

 

Also, before one buys cables and is not sure about specifications written on cable, you should ask the vendor/maunfacturer if those cables are poe capable and ensure they are not flameable.

 

Changing a cable and testing cat5 is good advice as those eap devices are certified only for cat5 (like most devices).

 

Where we speak about cables, on one location with YuaanLey gigabit switch, all cables connecting doses, eap's, controller, switches and ipcams, they all are connected with cat6a, on other location with same switch all cables are cat7. By that, I can confirm that cat6 and cat7 work in that constelation.

 

OP wrote that he knew he will be pointed to switch, that's why I wrote at all, as I can not confirm that YuanLey switches have any issues at all, they do excellently the task they should. Also, few cams are over 70m and this switch powers them still without any issues, anyway, there are restrictions in cable lenght for PoE and as far as I remember Pharos devices had something like 50-60m with cat5e cable. On both locations there are Pharos devices too and they too work without any issues with YuanLey switches.

 

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#13
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Re:Omada EAP power supply issues
2022-03-03 21:34:46

Cable specs vary. CAT6 7 8 are great at link speed. Yet, I still use 5e commonly on PoE. I connect my PC with CAT8 purely for stablilty. 

I am not saying CAT6 7 don't work with PoE. They are backward compatible. I think it could be a cable issue. 

Yes. Max PoE distance is up to the cable quality. If the PoE device runs well with the shorter cat6 7 8, or even cat5. That'll be the fault of the switch. 

Gigabit or Fast Ethernet does not matter in this case. I think. 

 

ScReW yOu gUyS. I aM GOinG hoMe. —————————————————————— For heaven's sake, can you write and describe your issue based on plain fact, common logic and a methodologic approach? Appreciate it.
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#14
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Re:Omada EAP power supply issues
2022-03-04 12:06:05

  @Tedd404 Not that it matters if it is gigabit or fast-ethernet, I just believe their hardware is not the same because. My point is, I tested only YuanLey switches with 1Gbit and cant say anything about 100Mbit devices as I did not use them with omada, but I saw YuanLey in many households, mainly those where some video surveilance existed.

 

For cables, I do normally preffer to use keystone modules for cables in walls, then from dose in a wall which is normally available at the workdesk, there then people can/do use very thin and flexible cable. If you want to make a joke with hidden cam on your workplace, replace all those desktop/notebook cables in that room with solid cooper cat7 :), then take a look how long it takes after first angry employee comes to ask for a flexible cable. I never lay and crimp cat5 cables, I buy them always finished, mostly those are 0.15cm-0.30cm.

 

In real, I have always cat7 cables and many connectors and keystone modules, meaning that it is costing me more to buy separately cat5 cables, wait for them and they are not in perfect length. For patch panel connections like 48 short 20cm cables, those I buy and save my time, but if I need just one, two cables, then it is mostly cat7 as it is here, do not need to wait for it. Those would be biggest differences for me personally, beside their technical specification.

 

For the point about bad cables, regardless which cat standard you choose, never buy cables with CCA written on cable (stands for Copper Clad Aluminum), that's more important, as if it is 100% cooper and you connect with shorter cables than 100m, you will be good with cat5e too.

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#15
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