Can I use а passive PoE injector with AC66U_B1?

  • ATTENTION! As of November 1, 2020, you are not able to reply to threads 6 months after the thread is opened if there are more than 500 posts in the thread.
    Threads will not be locked, so posts may still be edited by their authors.
    Just start a new thread on the topic to post if you get an error message when trying to reply to a thread.

dodko

Occasional Visitor
Hello,

So I use two AC66U_B1s as AiMesh nodes, connected to a AC68U main router. I am not satisfied with the result, as they drop the connection sometimes for a couple of seconds (other users here on the forum have reported the same issue). My question is if I can use a passive PoE injector thing (the cheap ones, that look like a splitter) with those routers? They are both situated in the hallway of two floors in a house. I have an ethernet cable running to each floor for a climate control system, which I can use for the routers. Unfortunately the only outlets in the hallways are on the opposite side of where the ethernet cable is located, and there is no way I can run a power cable (aesthetically wise). Right now the routers are connected to the main router wirelessly, because they are powered by the outlet, where there is no ethernet cable. So my only option is to use a Passive PoE injector, but I don't know if it would work with these routers? I don't care about having gigabit connectivity, as I've seen that the cheaper ones only support 100 mbps (the house is located in a small village, where the max speed from the ISP is 100 mbps anyways). I am just looking for reliability, because I'm tired of connection drops...
Any input would be appreciated, thanks! :)
 

Adooni

Regular Contributor
typical poe not but there are solution called POE splitter + injector - you would need one that allow to combine RJ45 and Asus power supply and at the end another poe splitter that take power and signal from RJ45 and split to RJ45 and power.
example https://www.amazon.com/dp/B00LV8X81I/?tag=snbforums-20 you need check your power supply connector size
 
Last edited:

bbunge

Part of the Furniture
Sure. Just make sure you match the voltage and wattage of the router and the router power plug. I have run a Netgear router as an access point like this for years. You will need a PoE "set" for each AiMesh node.
 

dodko

Occasional Visitor
typical poe not but there are solution called POE splitter + injector - you would need one that allow to combine RJ45 and Asus power supply and at the end another poe splitter that take power and signal from RJ45 and split to RJ45 and power.
example https://www.amazon.com/dp/B00NRHNPUA/?tag=snbforums-20 - you need check your power supply connector size
Yes, those are the exact type of injectors I meant, when I wrote the first post. I couldn't find one with a connector, that's the same size as the asus one. Would it work if I just cut the connector, cut the router's adapter and splice them together on each end, so I can use it's connector?
Sure. Just make sure you match the voltage and wattage of the router and the router power plug. I have run a Netgear router as an access point like this for years. You will need a PoE "set" for each AiMesh node.
I am planning to use the original adapter that comes with the router, so I guess your concerns won't apply for me?
 

Adooni

Regular Contributor
sure but you will need to do it at 2 ends - 1 cut and directly connect power supply and for another end cut and connect original power supply connector
I am sure you will find correct one it what size power connector do you need? you can find a lot different option on ebay.
 
Last edited:

dodko

Occasional Visitor
4.0mm x 1.35mm , that's what I was able to find here on the forum for the size of the connector.
 

Adooni

Regular Contributor
I would try to confirm it as looks like standard is 4.0x1.7mm or 3.5x1.35mm

maybe alternative would be to try find connectors adaptors from poe connector size to your router size.
 

dodko

Occasional Visitor
The problem is that, where I live there aren't many options for such injectors, and most of the ones i found are meant to be used with ip cameras with bigger connectors. Another option is chinese sites, but delivery tooks over a month... Would cutting and splicing them cause any issue, because it seems like that would be my only option?
 

Tech9

Very Senior Member
Would cutting and splicing them cause any issue, because it seems like that would be my only option?

Seems like you know what you are doing, so no. There are 2 wires there, no engineering degree required.
 

CaptainSTX

Part of the Furniture
Go to Amazon then Texas WiFi POE and see if you can find exactly what you need. I use a pair of their adapters to pass a both power and gig data to my switches.

The limitation will be the distance from where you insert the injectors to to the device to be powered. Their web site has tools to help you calculate the voltage drop.
 

dodko

Occasional Visitor
I live in Europe and amazon is not available where I am, unfortunately. I'm not very good at calculating distances, but I guess that it won't be more than 30 meters from the switch in the basement up to the 2nd and 3rd floor where the cables terminate. Most of the PoE splitters I found here say that they're are rated for up to 30 meters.
 

CaptainSTX

Part of the Furniture
Still visit the site I suggested to get an idea of what is available even if you have to find another source.

Also use the tools on their site to calculate voltage drop vs. distance. Thirty meters is going to be a push. Look at where you could insert the injector mid span to make it work. Someplace where AC power is available from an outlet.
 

dodko

Occasional Visitor
Unfortunately that's not an option. The ethernet cables are plastered into the wall. The only place I can put the injectors is in the basement, where the cables connect to the switch.
 

Tech9

Very Senior Member
AC66U_B1 in normal operation mode consumes about 12-14W. Cat5/6 copper cable 30m long will drop the 19V power supply voltage to router to about 17.3-17.5V. The router will work, nothing inside uses 19V. Asus drops the voltage down with multiple VRMs. Plugging something in USB ports may result in reboot though. The power supply voltage will fluctuate with the load. I would try it and if it works - good.
 

dodko

Occasional Visitor
The usb ports won't be used. Usage on those nodes will be mainly from phones, and one smart tv which may cause higher load.
I guess I'll just have to get an adapater and test. What are the symptoms if the voltage drops too much - instability or it would stop working at all?
 

Adooni

Regular Contributor
V (voltage) it is one question 2nd when you will be buying those device check what A (current) they can handle. I see same of those solutions show 1.5A and your router could need more. If as example you have such info "9~48V input" you will be OK from A point o view - Ohm’s Law (to be sure poe injector/splitter will survive current you will put throe it).
V drop you can measure with multimeter and as last result as it is very very dangerous you can use higher V AC/DC to have at the end your router V but if you go above router spec the end :(
You need to remember that "Temperature influences the conductivity of materials. Depending on the material and the actual temperature, conductivity may increase or decrease with further increases in temperature. Current is directly proportional to voltage drop. If current is doubled while resistance is kept the same, voltage drop also doubles"
 

dodko

Occasional Visitor
Thanks for the input guys. I will order one pair of PoE injectors, will set it up kn the 3rd floor, and if it works well for a while, I will get another pair for the router on the 2nd floor. :)
 
Similar threads
Thread starter Title Forum Replies Date
H Honey, I blew up the RT-AC86U! (Passive PoE blunder) ASUS AC Routers & Adapters 20

Similar threads

Latest threads

Sign Up For SNBForums Daily Digest

Get an update of what's new every day delivered to your mailbox. Sign up here!
Top