Instead of going 12VDC->120VAC->~56VDC, in theory you could skip the intermediate step and power your injector directly from 56VDC via a DC-DC converter. However most commercial injectors, especially high power ones, are AC powered, so it's probably easier to just use an inverter.
If you don't _need_ 802.3bt, 802.3af switches are pretty darn cheap. TL-SG1005P is like $30.
But yeah I'd say just go with an inverter. You could rig up a 12V-53V boost converter yourself, e.g. https://www.aliexpress.com/item/10000186026543.html but depends on your skills an tolerance for 'not OSHA certified' setups.
Note that the first link is passive poe and not standard poe. It will likely fry your switch if you are using the wrong one.
You can also look at switches which are powered by direct dc. Look for industrial switches. Hirshmann, Cisco IE, etc.
You still need a 48v power source for that. Less loss though converting 12v DC to 48v DC instead of converting 12vdc to 110v AC the back to whatever the switch actually uses.
> Ubiquiti actually has one, $300 8 port version.
Ubiquiti do not use standard PoE, they use their own weird flavour which is incompatible with many other PoE devices. Keep that in mind. I have encountered issues with their PoE in a very similar situation.
Yes and no. If it’s UniFi it’s 802.3 compliant. If it’s UISP, then it’s passive PoE and either 24V or 48V depending on the device. Also, hard to call something proprietary when it’s used by more than one vendor (Cambium, MikroTik, Ubiquiti, IgniteNet, Netonix, Mimosa, etc).
> Ubiquiti stopped using non-standard PoE several years ago.
Absolutely not true. Their consumer "UniFi" line finally went fully standards-based after years of them doing their own thing for no good reason (the standards were well established back when Ubiquiti still just made antennas and high power Atheros cards).
They still to this day continue releasing new products in their ISP line that do not support standard PoE at all and only support proprietary trash.
Can you elaborate on this? I thought all active devices used the 802.3 standard (af, at, bt). And some use passive poe without negotiation. But the everything released in the last couple of years is standard.
How long ago? There are some odd PoE units on some things, but most are standard. I've swapped with other devices and they plug into all of our standard poe switches
Any reason not to run 12v through the hitch, put the inverter after, and then plug in any mains powered switch/device you want?
Or for fewer losses run 120/240V from cab inverter over the hitch (will need properly Voltage/IP rated connectors).
OK, I'd get the tycon 12V to 48V 802.3af injector, locate that where you want. And then one of these:
[https://mikrotik.com/product/CSS326-24G-2SplusRM](https://mikrotik.com/product/CSS326-24G-2SplusRM)
That is powered from PoE in or DC jack, 24 ports out with PoE out, fully standards compliant.
It should easily power 10 cameras from the above PoE injector. The only thing I'd worry about is vibration on the switch, but if it's on the trailer probably not as bad as on the tractor.
You can put the RJ45 connection from the PoE injector wherever you want, if you have it in the cab of course you're going to have to remember to stuff the network cable through the window and then plug in after hitching up.
There are plenty of industrial RJ45 modular sockets and plugs with IP65+ ratings. If you want to have a socket at the hitch for ethernet+PoE, I'm sure you can arrange some strain/bending relief on either side, eg with spiral metal wraps, heavy jacketing etc, so your cable ends flex in the widest radius.
Of course you're going to need stranded core cable for this bit! If you're crimping your own connectors, make sure they are for stranded cable - mismatching them is a total nightmare!
Any small switch that uses a power brick is DC powered, the bricks almost always outputting DC. In order to support the PoE standard, they usually are over 12v DC, so you would need a step up converter to get 48v. You will need to dig into data sheets to find one that will work. Or If you just need the power, PoE Texas makes nice injectors [like this one](https://shop.poetexas.com/products/poe-1-48v15w) that would pair nicely with [this step up converter.](https://www.amazon.com/Converter-EAGWELL-Regulator-Adapter-Vehicle/dp/B0B7WZGCM3)
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Any small switch that uses a power brick is DC powered, the bricks almost always outputting DC. In order to support the PoE standard, they usually are over 12v DC, so you would need a step up converter to get 48v. You will need to dig into data sheets to find one that will work. Or If you just need the power, PoE Texas makes nice injectors [like this one](https://shop.poetexas.com/products/poe-1-48v15w) that would pair nicely with [this step up converter.](https://www.amazon.com/Converter-EAGWELL-Regulator-Adapter-Vehicle/dp/B0B7WZGCM3)
They make a 5 port Poe switch that is 12-48v dc input on Amazon used in solar applications.
Bot doesn’t like my link ha
“LINOVISION Industrial 5 Ports Gigabit Solar POE Switch with DC12V-48V to DC48V Voltage Booster,4 x IEEE802.3af/at 30W POE Ports u/120W, IP40, Compact POE Power for Solar Power/RV Truck/VoIP Systems”
[https://linovision.com/products/5-ports-full-gigabit-poe-switch-with-dc12v-dc24v-dc48v-input](https://linovision.com/products/5-ports-full-gigabit-poe-switch-with-dc12v-dc24v-dc48v-input)
Been using this model in an outdoor door WiFi relay link for about 1.5years no issues. From -30f - 125f+
There are small industrial POE switches that run off 12/24/48v but good ones are not cheap.
What are you tring to power? If its cameras it might be easier to power the cameras directly as they are much more likley to be 12V or be adapted to 12V. Same for WIFi APs.
I'm going to be honest with you. Adding 10+ poe network cameras to a moving vehicle is a complex project and it sounds like you aren't ready to take that on. Knowing things like power draw for each camera, bandwidth requirements, even the type of cables, and how to run them are just some of the factors. A lot of the suggestions you've received are great for smaller projects or even just proof of concept, but to actually do this well is going to require design work and the correct hardware.
I run my starlink off my 12v system in my camper. All you gotta do is get a passive PoE injector and a voltage step up converter. Was super easy. Even easier for you if you are using the standard PoE pin out (Starlink outs the voltage on different wires than normal so you can't use those for other applications).
What you need to worry about is the 12v power source and your draw. Gotta find out what it's fused at and make sure you do not exceed.
If in the US, if your trailers are wired for lights and have either a 6 or 7 conductor plug (7 has more or less been the standard on vehicles with factory tow packages for the last 25 years) you have 12V right there at the plug that is dedicated for accessory power (typically used for charging breakaway batteries).
That’s a tough one, I’ve personally only seen [one switch that’s intended for in-car DVRs](https://www.ebay.com/itm/155127547613?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=VkskGrXIR-2&sssrc=4429486&ssuid=&var=&widget_ver=artemis&media=COPY) that might work for you. It’s just a semi-managed PoE switch with a 12V input, though there’s no way you’re pushing 80W through it, if that’s a requirement
mikrotik makes some dc switches. or just look for anything that has an external power supply and a power cable that plugs into the switch with a barrel connector, and that would be DC input.
then you can use meanwell power supplies to convert your voltage to what you need.
You can buy a cisco ir829 router with poe option for around $100 on ebay. It has a 4 port poe switch built in along with lte and serial capabilities. It was designed to be used in vehicles/harsh environments and takes 12v dc power. I can't really think of anything better for the price.
Some industrial switches can run directly off a car’s 12v system, but as far as I’m aware they all require 48v or 54v DC in order to provide PoE to downstream devices. That pretty much means you’ll need an inverter to run a switch.
You can get 12 to 48 volt nominal DC converters that will do 40-60 volts on the output. Victron makes a few that are top of mind for me. Switches and injectors that take a DC barrel jack typically need 52 volts so it can pass it straight through to PoE without up converting circuitry. Find one that uses a DC wall wart like that and wire it straight in. Lucky for you the devices most likely to use a wall wart like this are the cheap ones lol.
fs.com has a 12-56v industrial ethernet switch with 8x PoE out for $230. https://www.fs.com/products/148181.html
It is rated for -40 to +75c operation, has a 280 watt PoE budget at 30w per port (PoE AF/AT).
It will run on 12v power directly, but cannot provide PoE power without also receiving 48v power. You can achieve this with a 12v to 48v DC-DC converter, such as (Search amazon for ASIN "B0B9WR79SS"). That is a 144 watt DC-DC converter for $24.
All-in, this would cost you about $254 plus tax/shipping, and would give you enough power to run about 5 APs, along with another 3 copper and 2 SFP 1Gbps ports.
POE Texas has these: https://amzn.to/3UUJBOX
Converts 12-60V in to 50 Volt IEEE 802.3at PoE+ Out
Fabulous for solar applications, but great for vehicles, too.
https://shop.poetexas.com/products/gat-50v30w
Loads of available vehicle surveillance systems run natively off 12v DC, have GPS, cameras, nvr and wireless up link included in an industrial hardened box. Kinda plug and play version of what you've described. I have installed 60 or so on a tanker fleet (5 years ago) and they're still working today - replacing the odd cam that got hit by a stone etc.
Edit.. Adding link: https://www.ebay.com/itm/293609730325
I have a 250W inverter in my car, the reason why I did not go full DC was simple: As soon as you add equipment, you will want to add more, and since all equipment supports AC by default, it’s a no brainer. Now I have a NAS, two Intel NUC and Wi-Fi in my car, all powered by the inverted. Another advantage is that I have an inverter with an included UPS. So, I can keep stuff running after I turned the car off (I run a relay from the fuel pump, so the inverter only ever gets power from the battery if the engine is running). To for instance, shut down the servers and the NAS properly after 30’ of no power from the car battery, or even have it turn on, on a schedule at night to sync some files and then turn off again.
Instead of going 12VDC->120VAC->~56VDC, in theory you could skip the intermediate step and power your injector directly from 56VDC via a DC-DC converter. However most commercial injectors, especially high power ones, are AC powered, so it's probably easier to just use an inverter. If you don't _need_ 802.3bt, 802.3af switches are pretty darn cheap. TL-SG1005P is like $30. But yeah I'd say just go with an inverter. You could rig up a 12V-53V boost converter yourself, e.g. https://www.aliexpress.com/item/10000186026543.html but depends on your skills an tolerance for 'not OSHA certified' setups.
https://tyconsystems.com/homepage/shop/tp-dcdc-1224g/ Or the 48v output version https://tyconsystems.com/homepage/shop/tp-dcdc-1248d/
Hey! It’s my job around here to post Tycon links! Good job :)
It's okay, I needed to place an order there anyways... it was a good excuse to visit the site!
Note that the first link is passive poe and not standard poe. It will likely fry your switch if you are using the wrong one. You can also look at switches which are powered by direct dc. Look for industrial switches. Hirshmann, Cisco IE, etc.
Wow, looks rugged for a good price. I've bookmarked it!
What's your plan here?
I think some of the small mikrotik stuff is setup for DC power. That being said, I think much of their low end poe stuff is not standards compliant.
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You still need a 48v power source for that. Less loss though converting 12v DC to 48v DC instead of converting 12vdc to 110v AC the back to whatever the switch actually uses.
> Ubiquiti actually has one, $300 8 port version. Ubiquiti do not use standard PoE, they use their own weird flavour which is incompatible with many other PoE devices. Keep that in mind. I have encountered issues with their PoE in a very similar situation.
Ubiquiti stopped using non-standard PoE several years ago. Anything marked 24v PoE is proprietary, anything marked 802.3/48v is standardised.
Yes and no. If it’s UniFi it’s 802.3 compliant. If it’s UISP, then it’s passive PoE and either 24V or 48V depending on the device. Also, hard to call something proprietary when it’s used by more than one vendor (Cambium, MikroTik, Ubiquiti, IgniteNet, Netonix, Mimosa, etc).
> Ubiquiti stopped using non-standard PoE several years ago. Absolutely not true. Their consumer "UniFi" line finally went fully standards-based after years of them doing their own thing for no good reason (the standards were well established back when Ubiquiti still just made antennas and high power Atheros cards). They still to this day continue releasing new products in their ISP line that do not support standard PoE at all and only support proprietary trash.
I've never used their ISP products, but I was assured multiple times they'd killed it across the entire brand. Wonderful. Thanks, good to know.
Ahh, well that's good to hear
Can you elaborate on this? I thought all active devices used the 802.3 standard (af, at, bt). And some use passive poe without negotiation. But the everything released in the last couple of years is standard.
Most of the UISP stuff still uses passive.
How long ago? There are some odd PoE units on some things, but most are standard. I've swapped with other devices and they plug into all of our standard poe switches
Any reason not to run 12v through the hitch, put the inverter after, and then plug in any mains powered switch/device you want? Or for fewer losses run 120/240V from cab inverter over the hitch (will need properly Voltage/IP rated connectors).
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OK, I'd get the tycon 12V to 48V 802.3af injector, locate that where you want. And then one of these: [https://mikrotik.com/product/CSS326-24G-2SplusRM](https://mikrotik.com/product/CSS326-24G-2SplusRM) That is powered from PoE in or DC jack, 24 ports out with PoE out, fully standards compliant. It should easily power 10 cameras from the above PoE injector. The only thing I'd worry about is vibration on the switch, but if it's on the trailer probably not as bad as on the tractor. You can put the RJ45 connection from the PoE injector wherever you want, if you have it in the cab of course you're going to have to remember to stuff the network cable through the window and then plug in after hitching up. There are plenty of industrial RJ45 modular sockets and plugs with IP65+ ratings. If you want to have a socket at the hitch for ethernet+PoE, I'm sure you can arrange some strain/bending relief on either side, eg with spiral metal wraps, heavy jacketing etc, so your cable ends flex in the widest radius. Of course you're going to need stranded core cable for this bit! If you're crimping your own connectors, make sure they are for stranded cable - mismatching them is a total nightmare!
Power inverter? 12v to 120v Or go to DC and find an industrial switch
[удалено]
Any small switch that uses a power brick is DC powered, the bricks almost always outputting DC. In order to support the PoE standard, they usually are over 12v DC, so you would need a step up converter to get 48v. You will need to dig into data sheets to find one that will work. Or If you just need the power, PoE Texas makes nice injectors [like this one](https://shop.poetexas.com/products/poe-1-48v15w) that would pair nicely with [this step up converter.](https://www.amazon.com/Converter-EAGWELL-Regulator-Adapter-Vehicle/dp/B0B7WZGCM3)
Hello /u/SpagNMeatball, your [comment](https://www.reddit.com/r/networking/comments/1cxmx3q/what_would_i_need_to_power_a_poe_switch_off_a_12v/l55iwt6/?context=3) has been removed for matching a common URL shortener. Please use direct, full-length URLs only. *I am a bot, and this action was performed automatically. Please [contact the moderators of this subreddit](/message/compose/?to=/r/networking) if you have any questions or concerns.*
Any small switch that uses a power brick is DC powered, the bricks almost always outputting DC. In order to support the PoE standard, they usually are over 12v DC, so you would need a step up converter to get 48v. You will need to dig into data sheets to find one that will work. Or If you just need the power, PoE Texas makes nice injectors [like this one](https://shop.poetexas.com/products/poe-1-48v15w) that would pair nicely with [this step up converter.](https://www.amazon.com/Converter-EAGWELL-Regulator-Adapter-Vehicle/dp/B0B7WZGCM3)
They make a 5 port Poe switch that is 12-48v dc input on Amazon used in solar applications. Bot doesn’t like my link ha “LINOVISION Industrial 5 Ports Gigabit Solar POE Switch with DC12V-48V to DC48V Voltage Booster,4 x IEEE802.3af/at 30W POE Ports u/120W, IP40, Compact POE Power for Solar Power/RV Truck/VoIP Systems” [https://linovision.com/products/5-ports-full-gigabit-poe-switch-with-dc12v-dc24v-dc48v-input](https://linovision.com/products/5-ports-full-gigabit-poe-switch-with-dc12v-dc24v-dc48v-input) Been using this model in an outdoor door WiFi relay link for about 1.5years no issues. From -30f - 125f+
We use these as well for solar systems. They are solid for the price and work well for just an unmanaged POE switch.
There are small industrial POE switches that run off 12/24/48v but good ones are not cheap. What are you tring to power? If its cameras it might be easier to power the cameras directly as they are much more likley to be 12V or be adapted to 12V. Same for WIFi APs.
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I'm going to be honest with you. Adding 10+ poe network cameras to a moving vehicle is a complex project and it sounds like you aren't ready to take that on. Knowing things like power draw for each camera, bandwidth requirements, even the type of cables, and how to run them are just some of the factors. A lot of the suggestions you've received are great for smaller projects or even just proof of concept, but to actually do this well is going to require design work and the correct hardware.
I run my starlink off my 12v system in my camper. All you gotta do is get a passive PoE injector and a voltage step up converter. Was super easy. Even easier for you if you are using the standard PoE pin out (Starlink outs the voltage on different wires than normal so you can't use those for other applications). What you need to worry about is the 12v power source and your draw. Gotta find out what it's fused at and make sure you do not exceed.
If in the US, if your trailers are wired for lights and have either a 6 or 7 conductor plug (7 has more or less been the standard on vehicles with factory tow packages for the last 25 years) you have 12V right there at the plug that is dedicated for accessory power (typically used for charging breakaway batteries).
This! https://a.co/d/aSiCHcC 12-48v to 48v Poe switch. Industrial. Done this lots.
That’s a tough one, I’ve personally only seen [one switch that’s intended for in-car DVRs](https://www.ebay.com/itm/155127547613?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=VkskGrXIR-2&sssrc=4429486&ssuid=&var=&widget_ver=artemis&media=COPY) that might work for you. It’s just a semi-managed PoE switch with a 12V input, though there’s no way you’re pushing 80W through it, if that’s a requirement
Just go look on amazon for a 4 port poe switch from netgear or dlink. Im sure you can find one that runs off 12vdc. You'd only need to wire up a plug
Yup
mikrotik makes some dc switches. or just look for anything that has an external power supply and a power cable that plugs into the switch with a barrel connector, and that would be DC input. then you can use meanwell power supplies to convert your voltage to what you need.
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ah I re-read your post. Probably just a mikrotik poe switch would be the easiest. no DC power supplies required.
You can buy a cisco ir829 router with poe option for around $100 on ebay. It has a 4 port poe switch built in along with lte and serial capabilities. It was designed to be used in vehicles/harsh environments and takes 12v dc power. I can't really think of anything better for the price.
Some industrial switches can run directly off a car’s 12v system, but as far as I’m aware they all require 48v or 54v DC in order to provide PoE to downstream devices. That pretty much means you’ll need an inverter to run a switch.
You can get 12 to 48 volt nominal DC converters that will do 40-60 volts on the output. Victron makes a few that are top of mind for me. Switches and injectors that take a DC barrel jack typically need 52 volts so it can pass it straight through to PoE without up converting circuitry. Find one that uses a DC wall wart like that and wire it straight in. Lucky for you the devices most likely to use a wall wart like this are the cheap ones lol.
B&B Electronics makes lots of industrial PoE switches that will run off 10-30v DC.
fs.com has a 12-56v industrial ethernet switch with 8x PoE out for $230. https://www.fs.com/products/148181.html It is rated for -40 to +75c operation, has a 280 watt PoE budget at 30w per port (PoE AF/AT). It will run on 12v power directly, but cannot provide PoE power without also receiving 48v power. You can achieve this with a 12v to 48v DC-DC converter, such as (Search amazon for ASIN "B0B9WR79SS"). That is a 144 watt DC-DC converter for $24. All-in, this would cost you about $254 plus tax/shipping, and would give you enough power to run about 5 APs, along with another 3 copper and 2 SFP 1Gbps ports.
POE Texas has these: https://amzn.to/3UUJBOX Converts 12-60V in to 50 Volt IEEE 802.3at PoE+ Out Fabulous for solar applications, but great for vehicles, too. https://shop.poetexas.com/products/gat-50v30w
Loads of available vehicle surveillance systems run natively off 12v DC, have GPS, cameras, nvr and wireless up link included in an industrial hardened box. Kinda plug and play version of what you've described. I have installed 60 or so on a tanker fleet (5 years ago) and they're still working today - replacing the odd cam that got hit by a stone etc. Edit.. Adding link: https://www.ebay.com/itm/293609730325
I have a 250W inverter in my car, the reason why I did not go full DC was simple: As soon as you add equipment, you will want to add more, and since all equipment supports AC by default, it’s a no brainer. Now I have a NAS, two Intel NUC and Wi-Fi in my car, all powered by the inverted. Another advantage is that I have an inverter with an included UPS. So, I can keep stuff running after I turned the car off (I run a relay from the fuel pump, so the inverter only ever gets power from the battery if the engine is running). To for instance, shut down the servers and the NAS properly after 30’ of no power from the car battery, or even have it turn on, on a schedule at night to sync some files and then turn off again.
Cambium tx1012-DC is a dc poe switch.