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marklodge
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Does CRS328-24P-4S+RM support 24v passive poe?

Sun Sep 29, 2019 1:26 pm

Does CRS328-24P-4S+RM support 24v passive poe?

https://mikrotik.com/product/crs328_24p_4s_rm

I need to power around 20 x UBNT Rocket Prisms/air fiber and LHGs.
 
Zacharias
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Re: Does CRS328-24P-4S+RM support 24v passive poe?

Sun Sep 29, 2019 1:29 pm

 
Paternot
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Re: Does CRS328-24P-4S+RM support 24v passive poe?

Sun Sep 29, 2019 5:51 pm

Yes, it does. I'm using one to power two RB1100AHx2 and one hAP ac2 - all of them with 26 volts.
 
Elans
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Re: Does CRS328-24P-4S+RM support 24v passive poe?

Mon Sep 30, 2019 7:54 am

Before you ask such questions here, you could simply check device specification section. If you did not find an answer on your question there, please take a look at brochure where you could find more detailed information and device description.
https://i.mt.lv/cdn/rb_files/CR328-24P- ... 120301.pdf
 
UpRunTech
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Re: Does CRS328-24P-4S+RM support 24v passive poe?

Fri Oct 04, 2019 12:51 pm

I am glad it has this feature. I installed some of these CRS328's on a site that already had wAPACs. They OVERHEATED and crashed a lot on 802.3af/at and luckily when I switched to 24V they behaved normally again. Another site has wAPACs with a HP 802.3af/at switch and they don't carry on like that. It's great that you can set the PoE mode on a per port basis.
 
Zacharias
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Re: Does CRS328-24P-4S+RM support 24v passive poe?

Fri Oct 04, 2019 1:32 pm

They OVERHEATED and crashed a lot on 802.3af/at and luckily when I switched to 24V they behaved normally again.
I guess because of higher voltage..
But they crashed ?
 
UpRunTech
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Re: Does CRS328-24P-4S+RM support 24v passive poe?

Fri Oct 04, 2019 1:57 pm

They OVERHEATED and crashed a lot on 802.3af/at and luckily when I switched to 24V they behaved normally again.
I guess because of higher voltage..
But they crashed ?
Yes. They'd run for a while then lock up tighter than a duck's cloaca. There was no relief until the voltage was dropped. They had been running off 24V injectors before and were fine. Maybe it was just a bad batch but the warranty had expired so I couldn't make it my suppliers problem.
 
andriys
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Re: Does CRS328-24P-4S+RM support 24v passive poe?

Fri Oct 04, 2019 6:15 pm

I installed some of these CRS328's on a site that already had wAPACs. They OVERHEATED and crashed a lot on 802.3af/at
I have 4 wAP ac units powered by CRS328-24P-4S+RM which have been running just fine for months already. As of this writing the uptime of all the units is over 82 days, and the switch reports current voltage to be 52V (i.e. af/at mode). The wAP ac units themselves report the input voltage to be only ~38V, though. What cables do you use (cat, length)?
 
UpRunTech
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Re: Does CRS328-24P-4S+RM support 24v passive poe?

Sat Oct 05, 2019 2:20 am

I installed some of these CRS328's on a site that already had wAPACs. They OVERHEATED and crashed a lot on 802.3af/at
I have 4 wAP ac units powered by CRS328-24P-4S+RM which have been running just fine for months already. As of this writing the uptime of all the units is over 82 days, and the switch reports current voltage to be 52V (i.e. af/at mode). The wAP ac units themselves report the input voltage to be only ~38V, though. What cables do you use (cat, length)?
The other site with wAPACs on the HP 802.3at/af switch are warm - not hot - but never had a problem. So as I said the ones at the problem site might be just a dodgy batch. Both sites though when on 802.11at/af have the wAPACs reporting 37V. So there is a scaling scaling problem in the hardware or software of the voltage ADC of the devices or there is a large voltage drop maybe generating a ton of heat. I am using cAPACs now instead for any new jobs and they are great! I only use wAPACs outdoors or in dirty environments. The cabling on the problem site is CAT6 all under 100m.
 
Zacharias
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Re: Does CRS328-24P-4S+RM support 24v passive poe?

Sat Oct 05, 2019 8:38 am

Do you know the exact temperature?
Also your cable is under 100m but how long?
The quality of the cable? You can have a great voltage drop because of bad quality cable...
 
roque86
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Re: Does CRS328-24P-4S+RM support 24v passive poe?

Sun Oct 06, 2019 6:39 pm

Hello everyone,

Just to double check, it would by fine to use a CRS328-24P-4S+RM to power a CSS326-24G-2S+RM on its passive PoE in port that only accepts 10-30v, right?
 
Zacharias
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Re: Does CRS328-24P-4S+RM support 24v passive poe?

Mon Oct 07, 2019 7:15 pm

The manual says it accepts poe in https://mikrotik.com/product/CRS326-24G ... -downloads...

The CRS328 according to the manual can power af/at and passive poe devices with max power consumption of 30W per port.. CRS 326 has a max power consumption of 24W i think...

So yes it can.. however personally i wouldnt do it...
 
roque86
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Re: Does CRS328-24P-4S+RM support 24v passive poe?

Tue Oct 08, 2019 6:06 pm

Thanks Zacharias.

I am currently powering 7 CSS326-24G-2S+RM with the CRS328-24P-4S+RM. I am still not stressing anything (they are only using 7W), but it is working quite well.
Any reason why you would advice against powering them wih PoE? By the way, they max at 19W, not 24W.
 
marekm
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Re: Does CRS328-24P-4S+RM support 24v passive poe?

Tue Oct 08, 2019 6:48 pm

I can confirm CRS326-24G-2S+RM works fine powered by PoE from CRS328-24P-4S+RM.
But, some power-hungry devices can have issues - one such example so far: Siklu EtherHaul 1200F (licensed 70/80GHz 1Gbps FDX PtP link).
It claims to be PoE+ 802.3at compatible but when powered from the CRS328, link was flapping (as if the ethernet transformer was saturated by high DC current) even though no overload was reported by the CRS and the EH was not rebooting.
The EH works well powered from external DC power connector, or PoE with another passive injector inserted between the EH and the CRS, so it's not a link auto-negotiation issue - tested two different ones: 48V 0.5A from RocketM5-Ti (this one started rebooting the EH when it got too hot in summer - but worked fine when cold), and 56V 0.93A from Mimosa A5 (this one has been stable for a long time, even in summer).
Mimosa A5 itself is quite power-hungry too, but works fine powered from the CRS.
Could it be that the EH draws high current in some short peaks that saturate the transformer (causing ethernet link down) but are too short to trip CRS overload protection?
 
Zacharias
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Re: Does CRS328-24P-4S+RM support 24v passive poe?

Tue Oct 08, 2019 9:48 pm

Any reason why you would advice against powering them wih PoE? By the way, they max at 19W, not 24W.
No..! According to the manual the max power consumption is 24W...
 
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xvo
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Re: Does CRS328-24P-4S+RM support 24v passive poe?

Tue Oct 08, 2019 9:54 pm

Any reason why you would advice against powering them wih PoE? By the way, they max at 19W, not 24W.
No..! According to the manual the max power consumption is 24W...
You are confusing CSS326 and CRS326.
 
roque86
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Re: Does CRS328-24P-4S+RM support 24v passive poe?

Wed Oct 09, 2019 3:53 pm

Any reason why you would advice against powering them wih PoE? By the way, they max at 19W, not 24W.
No..! According to the manual the max power consumption is 24W...
You are confusing CSS326 and CRS326.
Indeed.
On my first post I mentioned that I have the CSS326-24G-2S+RM, not the CRS326-24G-2S+RM.
Zacharias replied mentioning the CRS326 but I just assumed it to be a typo, given that I mentioned the CSS, not CRS. My bad.

Anyway, confusion apart, any reason why powering a set of CSS326-24G-2S+RM from a CRS328-24P-4S+RM would be discouraged, or that only applies to the CRS326?
I am assuming that it was mentioned because the CRS326 consumes a maximum of 24W and that would be close to the minimum power available when using 802.3at (25.5). Given that i do not have a CRS326, but a CSS326 instead, which goes up to 19w, this should not be a concern. Right?
 
Zacharias
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Re: Does CRS328-24P-4S+RM support 24v passive poe?

Wed Oct 09, 2019 8:36 pm

I guess it should be fine...
 
marklodge
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Re: Does CRS328-24P-4S+RM support 24v passive poe?

Sun Nov 10, 2019 6:49 pm

Before you ask such questions here, you could simply check device specification section. If you did not find an answer on your question there, please take a look at brochure where you could find more detailed information and device description.
https://i.mt.lv/cdn/rb_files/CR328-24P- ... 120301.pdf
I did check the spec sheet.
I read it twice.
For future, could you tell me where this is shown explicitly?
 
Zacharias
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Re: Does CRS328-24P-4S+RM support 24v passive poe?

Sun Nov 10, 2019 7:53 pm

In the download section of the product's page there is the brochure and the quick guide...
 
marklodge
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Re: Does CRS328-24P-4S+RM support 24v passive poe?

Sat Nov 16, 2019 9:28 am

Thanks.
And special thanks to the kind people who answered my post.

I have downloaded the quick guide and here i have copied the relevant info:

Power output
This device can supply PoE powering to external devices from its Ethernet ports. The output voltage will be
selected automatically, depending on what kind of voltage the connected device requires. The device can power
both 802.3af/at devices and devices that accept passive PoE power. If necessary, the output voltage can be
switched manually. By default the PoE mode is set to auto, it will not damage devices and will auto-detect devices
with PoE support and the needed voltage. Once a PoE device is detected, it will be powered and the PoE LEDs will
turn on.
The PoE out ports is grouped in three PoE out groups of 8 ports each (PSE8). Total device PoE limit = 450w (150w
per PSE8 group).
Each port can provide up to 30 W with high voltage, and 26,5 W with low voltage power output.

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