Beginner question - POE 12V, 24V, 48V

[younginitiative]

I am installing my first Dahua camera (N85FB7Z) after using Ubiquiti for several years.

From what the sales department told me, it's a 48V system (and what few details I can scratch up online seem to confirm this). Why, then, is a 12V adapter recommended?

Is it correct that this is a 48V POE camera? If it's converting down to 12V, internally, can I just use my 24V Mikrotik router to power it? I don't mind experimenting, but I hate to fry a good camera right out of the box.

Thanks, in advance, for any input.

 

[tigerwillow1]

You can power that camera through the 12 volt power jack on the pigtail OR via POE in which case it's powered via the network cable. To power over POE the camera has to be plugged into an 802.3at (aka POE+) switch. Since the camera needs a 15 watt supply, a non-plus POE switch won't do. Using POE makes things a lot simpler, but you have the choice. Another option is to use a POE injector of suitable power on the network cable. Since I don't use any of them I don't want to give any details and accidentally make a mistake.

 

[flynreelow]

just get a POE switch and be done with it.

 

[Broachoski]

The camera has internal circuit board which converts the 12 from the pigtail to the needed 44-57 volts needed.

 

[tangent]

The camera has internal circuit board which converts the 12 from the pigtail to the needed 44-57 volts needed.

Not exactly, internally most of it is going to run at 5V, 3.3V, and/or 1.2V. Some parts like the IR lights and IR filter or motors in a PTZ may operate at a higher voltage. The camera converts ~48V down to 12V, and then down to the lower voltages used by various components.

Is it correct that this is a 48V POE camera? If it's converting down to 12V, internally, can I just use my 24V Mikrotik router to power it? I don't mind experimenting, but I hate to fry a good camera right out of the box.

There are a bunch of different variants of PoE as you've noted. Your best option is to simply buy an 802.3af/at PoE switch, avoid any injectors that are using 'passive' 48V PoE. Lower voltage passive PoE won't work and it's harder to reliably power a camera off of 12VDC.

 

[guykuo]

Yes, get yourself a proper POE switch. Saves a LOT of worry and hassle regarding running wires. Just run ethernet and be done with it. No extra lines for delivering 12 volts. No janky injectors. No non-standard, weird/fake "POE". They are pretty inexpensive.

For $140 to $160 you can get a decent switch that has 16 POE+ ports.
TP-Link TL-SG116P | 16 Port Gigabit PoE Switch | 16 PoE+ Ports @120W total capacity is fanless (silent) and works well even with higher demand PTZ's. You will eventually want that power capability. I would skip POE switches that only support POE. You want POE+

https://www.amazon.com/gp/product/B0C4X7VZV9

I have several of these $149 switches that let me log into the switch and remotely turn individual POE ports on/off. That is really nice capability, but has rather noisy fan. Fine for connection closet, but not in your office. Also, these only have POE+ power on eight of their 16 ports.

https://www.amazon.com/gp/product/B0721V1TGV

At any rate, just get a switch. The "savings' of using injectors is quickly overcome by any system expansion.

 

[younginitiative]

This is helpful; thank you!

I already have the old POE switch in place and have CAT6 run to the camera location where a Ubiquiti camera is currently running. The Mikrotik I'm using as a switch is the old PowerBox, so it's POE and not POE+ that the new "Pro" version has. For today I'll use an injector to get the cameras swapped and everything configured, and I'll evaluate a permanent solution to replace it.

I'm still not clear how it can take a 12V on-site or a 48V through the cable but not a 24V through the cable, but I'll chalk this up to ignorance and move forward.

Thank you, again, for the fast input.

 

[tangent]

I am installing my first Dahua camera (N85FB7Z)

I already have the old POE switch in place and have CAT6 run to the camera location where a Ubiquiti camera is currently running. The Mikrotik I'm using as a switch is the old PowerBox, so it's POE and not POE+ that the new "Pro" version has.

This camera doesn't need PoE+ aka 802.3at, but it does need actual 802.3af PoE, which the Mikrotik PowerBox DOES NOT provide (this Mikrotik provides 24V Passive "PoE").

Also note, PoE+ 802.3at switches are backwards compatible with 802.3af.

Depending on your plans, you're probably better off with at least an 8 port PoE switch, but there are some basic 4-5 port 802.3af/at ones that are pretty cheap. like:

https://www.microcenter.com/product...-(1-x-high-power-poe)-for-camera-installation

 

[guykuo]

Mikrotik provides 24V Passive PoE

Which is what I mean by non-standard, weird/fake "POE". Passive power over ethernet like the Mikrotik and some Ubiquity products use is not the same as the power standards used by POE cameras.

As tangent wrote, you need real 802.3at /af compliant switches to properly power the cameras we talk about on this forum. Get a proper POE switch. EOS

 

[wittaj]

We would love to hear what they charged you for the N85FB7Z that will have trouble performing well in low light conditions...

And as others said, you can't use the equipment you got, get a real POE switch and be done with it.

Can't tell you how many times we have people come here saying their camera doesn't work only to find it out they were trying to power it with Mikrotik/Ubiquity products...

 

[looney2ns]

Which is what I mean by non-standard, weird/fake "POE". Passive power over ethernet like the Mikrotik and some Ubiquity products use is not the same as the power standards used by POE cameras.

As tangent wrote, you need real 892.3at /af compliant switches to properly power the cameras we talk about on this forum. Get a proper POE switch. EOS

I believe you meant 802.3 AT Poe+ switch

 

[guykuo]

I believe you meant 802.3 AT Poe+ switch

Fixed

 

[tigerwillow1]

I'm still not clear how it can take a 12V on-site or a 48V through the cable but not a 24V through the cable,

The camera runs off of 12 volts. There are 2 ways to supply power to the camera (1) The power connector on the camera (12 volts), or via the ethernet line (nominal 48 volts). The camera has circuitry that converts the 48 volts on the ethernet line to 12 volts. There is no option for 24 volts. It's 12 volts at the camera, or 48 over the ethernet line.

 

[tigerwillow1]

Correction to my post #2. Before posting this I read the camera specs from a sales web site that said it consumes 15 watts, above what's supplied with standard (not +) POE. Looking now at the official Dahua spec sheet, the camera's max draw from POE is 12.8 watts, just under the guaranteed 12.95 watt minimum available when using a standard 802.3af POE switch that supplies 15.4 watts at its port. So any old 802.3 compliant POE switch should work, at least in theory.

N85FB7Z spec sheet

 

[younginitiative]

I don't want to take this post too far off subject, but I have two follow-up questions:
1. Is af/at compliance always 48V?
2. Referring to the comment by @wittaj
I'm watching this camera after dark, and the night vision is no worse than the Ubiquiti it replaced (which might not be saying much).
Is there an existing thread recommending cameras? We are feeling our way into this hardware selection and, overall, we are disappointed with the 4MP/8MP qualities at the distances we use (200'+/-) Is it unrealistic to expect any decent performance at these distances? I can start a new thread if this hasn't been addressed recently.

Great input from everyone; thank you.

 

[flynreelow]

I don't want to take this post too far off subject, but I have two follow-up questions:
1. Is af/at compliance always 48V?
2. Referring to the comment by @wittaj
I'm watching this camera after dark, and the night vision is no worse than the Ubiquiti it replaced (which might not be saying much).
Is there an existing thread recommending cameras? We are feeling our way into this hardware selection and, overall, we are disappointed with the 4MP/8MP qualities at the distances we use (200'+/-) Is it unrealistic to expect any decent performance at these distances? I can start a new thread if this hasn't been addressed recently.

Great input from everyone; thank you.

ubiquiti 48v is not the same as normal POE and usualy comes in an injector form.

you are really wanting to see something from 200 feet away?

please post a picture.

 

[wittaj]

It is your thread, so you can take it anywhere you want!

Not all Power is the same - and many brands such as Ubiquity use their own proprietary standard to essentially "lock" customers into their systems. If you are moving away from that, then you need to move away from their power supply and go with true POE. Otherwise you run the risk of burning up the camera or the switch.

POE af/at is an industry standard and if the switch doesn't specifically state af/at then in all likelihood it won't work regardless of whether it claims the same voltage.

At 200 feet, if you want IDENTIFY capabilities, you need a PTZ. And will probably need supplemental light - either more IR or white light.

At that distance, you need cameras on the ideal MP/sensor ratio, which would be anything in green.



See this thread for the commonly recommended cameras (along with Amazon links) based on distance to IDENTIFY that represent the overall best value in terms of price and performance day and night.

The Importance of Focal Length over MP in camera selection

At the urging of several folks here, I created a thread to show the importance of focal length and how focal length can be more important than megapixels (MP). I mentioned some of this in the post regarding The Hookup’s latest video demonstrating different cameras, including one sold from a...

ipcamtalk.com

And then you need to get them off of default/auto settings to get the most out of them.

 

[younginitiative]

Got it; I'll keep this in mind as we move away from Ubiquiti. Some of the new MK hardware claims AF/AT So, I assume it's compliant, but we aren't installing everything overnight and having to decide right away.

We are working in a rural area with large, open spaces with traffic in and out for deliveries, plenty of foot traffic as we work, etc. Our mounting areas are limited and there is no "bottleneck" where we could record all in/out passages. It doesn't mean 200' is mandatory, but it's a shoot-from-the-hip number.

 

[flynreelow]

Got it; I'll keep this in mind as we move away from Ubiquiti. Some of the new MK hardware claims AF/AT So, I assume it's compliant, but we aren't installing everything overnight and having to decide right away.

We are working in a rural area with large, open spaces with traffic in and out for deliveries, plenty of foot traffic as we work, etc. Our mounting areas are limited and there is no "bottleneck" where we could record all in/out passages. It doesn't mean 200' is mandatory, but it's a shoot-from-the-hip number.

you will def want a nice PTZ with a nice zoom.

 

[jnissen]

Sorry to dredge up this post but I have a related question that I have yet to find an answer. If I power my cameras via POE is the 12V jack on the camera "live" or is it unpowered? I want to potentially run an external alarm speaker off 12V and would like to avoid a separate POE splitter with a 12V dual headed jack adapter. BTW - I would only use a few mA of additional current as the external siren would be battery backed. It's only to maintain the internal battery.

I have a camera here that I may power up and test it with but figured this should be common knowledge in the community.