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modarresi
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POE Out

Tue Apr 23, 2019 10:53 am

Hi

Can I power on RB951u2hnd with Poe Out of another RB951 with a defult power adapter on the router box

Thanks
 
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karlisi
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Re: POE Out

Tue Apr 23, 2019 11:03 am

Typical RB951 power consumption is about 0.13A on startup and about 0.1A when running. If this is 24V 0.8A power adapter then yes, you can, because both RBs will use 0.26A max.
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Karlis
 
modarresi
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Re: POE Out

Tue Apr 23, 2019 11:31 am

Thanks for replay

ُُSo, as you say we can series about 6 RB951 together with on power
 
mkx
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Re: POE Out  [SOLVED]

Tue Apr 23, 2019 3:16 pm

Specs mention that max PoE out current is 500mA and max power consumption of single unit to be 6.5W (at 24V supply voltage that translates to 271mA).

So to be on safe side, supplied power adapter is capable of powering almost 3 units at the same time (probably it could power 3 units as probability of all 3 drawing full power at the same time is less than certainty). And, again to be on safe side, only one unit can be powered through master's PoE out interface.

Any other interpretation might lead to problems.

BTW, I'd expect to see full power draw not at startup but rather during full WiFi load: around 1W emitted max power through antenna (that's not average power which cheap power meters might display, average is less due to Tx/Rx time sharing) and PA is not perfect (some losses there). Add power to process packets that are about to get radiated. All that on top of usual routing/bridging/firewalling ... when booting it's just CPU running at full speed and some initialization of wireless card.
BR,
Metod
 
modarresi
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Re: POE Out

Tue Apr 23, 2019 10:40 pm

Thanks,

It's a really good analyst and you right
we can almost 3 units at the same time if our device, not overload because 3*6.5w=19.5 W and our supply is 24 V , 0.8 A calc supply
watt out put==>24*0.8= 19.3 W
It's maybe damaged wireless chip because the power supply a little Weaker

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