WS-26-400-IDC for Power without Ethernet

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kiwibrew
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WS-26-400-IDC for Power without Ethernet

Mon Jun 19, 2017 5:34 am

Can I use the WS-26-400-IDC as a PoE only source (no Ethernet) for wireless backhaul radios like the UniFi AC Mesh? I'm asking about the 26-400-IDC because my supply is telco -48V. I'm fine with the voltage drop, the pairs are 18AWG. I've got pole access and plenty of free copper pairs in some neighbourhoods where it's a long distance between where I've got power and where I need power. Think 500 meters or more between my cabinet and location I want power.
1.) Is this going to work?
2.) What the max distance I can go at 10 watts per port if I don't care about voltage drop?
3.) Do I need to be worried about anything?
4.) Should I add extra lightning protection?
5.) Do I want/need to earth at the far end?

Thanks!

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Re: WS-26-400-IDC for Power without Ethernet

Wed Aug 09, 2017 10:33 pm

Hey Dave any thoughts here? Will I run into problems using the switch as a power source over telephone cable at 300m? 500m?

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sirhc
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Re: WS-26-400-IDC for Power without Ethernet

Thu Aug 10, 2017 1:48 pm

The biggest issue I see here is the radius and the switch will be on 2 differnt grounding systems.

If you are using Ethernet to carry the power make sure you use 48VH or 24VH that way you are using all 4 pair to carry the wattage. Only using 24V or 48V limits you to 2 pair to carry the power and you will suffer more voltage drop and use more watts.


Here are some good posts on grounding:
http://forum.netonix.com/viewtopic.php? ... 279#p19279
http://forum.netonix.com/viewtopic.php?f=30&t=1816
http://forum.netonix.com/viewtopic.php?f=30&t=188
http://forum.netonix.com/viewtopic.php? ... =30#p13447
http://forum.netonix.com/viewtopic.php?f=30&t=1429

If the radio is grounded to ground rods that are not bonded to the same Earth ground that the switch is then the Ethernet cables become the bond and ANY ground potential difference will travel through the switch-cable-radio and POOF

99% of WISP Equipment is damaged from ground current from having 2 separate ground systems bonded by the Ethernet cable.

You can NOT use standard Ethernet Surge Protector with passive POE because they work by clamping all 8 wires together to earth ground which make a DEAD SHORT which will damage the switch as all passive POE switches currently on the market use Polyfuses which open too slowly to protect the Ethernet transformer and sometimes depending on how the transformer burns out can also travel back to the PHY and or SOC and trash the switch.

We are working on a next generation design of passive POE switches that do not use Polyfuses to protect against shorts to prevent fires but those are not yet available.

Most Ethernet Surge Protector are designed to work with active POE 802.3af/at which can detect the short and shut off POE fast enough to prevent damage but those POE controller chips do not support passive POE nor are they designed to deliver .75A to 1.5A which is what people in the WISP industry want.
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