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433ah current draw

Posted: Mon Oct 06, 2008 5:53 am
by Equis
Hello

Can someone tell me what the current draw for a rb433ah is (without minipci)

Thanks

:-)

Re: 433ah current draw

Posted: Mon Oct 06, 2008 6:42 am
by QpoX
Same as RB333

Re: 433ah current draw

Posted: Mon Oct 06, 2008 6:46 am
by Equis
Just found it in the 333 manual!

it says 3W, can it really use that little power?

:-)

Re: 433ah current draw

Posted: Mon Oct 06, 2008 6:57 am
by QpoX
Just found it in the 333 manual!

it says 3W, can it really use that little power?

:-)
Ahh! thought you ment the board layout :)
*Lost in translation*

But yes 3W and 16W for the mini-pci slots...
If i remember correctly...

Re: 433ah current draw

Posted: Mon Oct 06, 2008 4:49 pm
by omega-00
Easy to hold up for hour and hours with a decent UPS too :-D

Re: 433ah current draw

Posted: Thu Jun 04, 2009 11:28 pm
by changeip
I wanted to followup on this. The 3W rating for the 433ah, is that at 12v or 24v?

Anyone have hard numbers of what a 433AH with a single XR5 takes at 24v ? I see that the XR5 states max 1.8a, but that's at 3.3v I believe. Trying to determine how many PoE runs I need to power a handful of those 450 feet away... Because of distance I can't use PoE with data - so I need to determine if I can use fiber and then power a small switch and a few 433ah's.

XR5
----
1.8A at 3.3v is 5.94W.
5.94W at 24v is .24A ?

433AH
----
3w at 24v is .125A ?

Is my calculation right that an XR5 and 433AH should be around .364A at 24v ? I know that's max current, I am planning for the worst. At idle I'm guessing it's less.

The POE-24i from PacWireless states 0.8A at 24v. Does this mean I could possibly run 2 433ah/xr5 combos from a single POE-24i? I know at 450 feet I am going to have loss and would not be able to run 2, just trying to figure out numbers. I plan on using all 8 pins of a cat6 cable for power. Anyone chime in with real world experience?

Re: 433ah current draw

Posted: Fri Jun 05, 2009 9:35 am
by RK
With a high quality cat5e cable, you can run RB433AH + one XR5 at 450 feet with a POE-24i.
You might not get 100 Mbps, but it sounds like you don't need more than 60 Mbps anyway.
You can forget about running two from a single POE-24i, even if you do use all 8 wires for power.

Pac Wireless does make a 50W 24V power supply and Mikrotik has one at 38W.

Re: 433ah current draw

Posted: Fri Jun 05, 2009 9:41 am
by changeip
What about using 48v and then converting back to < 24v at the far end? The drop isn't that much different, just wondering if it will keep the wires cooler.

Since it's too far for ethernet I was planning on using fiber and a converter, if i can find a low power one. I think I saw a brochure for one that was 400mA at 5v I believe.

Re: 433ah current draw

Posted: Fri Jun 05, 2009 4:31 pm
by roc-noc.com
I wanted to followup on this. The 3W rating for the 433ah, is that at 12v or 24v?

Anyone have hard numbers of what a 433AH with a single XR5 takes at 24v ? I see that the XR5 states max 1.8a, but that's at 3.3v I believe. Trying to determine how many PoE runs I need to power a handful of those 450 feet away... Because of distance I can't use PoE with data - so I need to determine if I can use fiber and then power a small switch and a few 433ah's.

XR5
----
1.8A at 3.3v is 5.94W.
5.94W at 24v is .24A ?

433AH
----
3w at 24v is .125A ?

Is my calculation right that an XR5 and 433AH should be around .364A at 24v ? I know that's max current, I am planning for the worst. At idle I'm guessing it's less.

The POE-24i from PacWireless states 0.8A at 24v. Does this mean I could possibly run 2 433ah/xr5 combos from a single POE-24i? I know at 450 feet I am going to have loss and would not be able to run 2, just trying to figure out numbers. I plan on using all 8 pins of a cat6 cable for power. Anyone chime in with real world experience?
The voltage doesn't matter when you are talking watts. Watts is the power draw no matter what voltage is used. So if you have a 3 watt draw for the RB433AH and you are using a 19 watt power supply like the 18POW, then you have 16 watts left over for radio cards and potential line loss (when running POE).

You only need to concern yourself with voltage when you have current measurements (amps) and want to find out the power (watts). Then: volts * amps = watts.

Tom

Re: 433ah current draw

Posted: Fri Jun 05, 2009 6:50 pm
by changeip
So are my calulations about right for the 433ah and an XR5? 0.364A at 24v (or 8.74W) for that setup?

Thx,
Sam

Re: 433ah current draw

Posted: Fri Jun 05, 2009 8:05 pm
by RK
So are my calulations about right for the 433ah and an XR5? 0.364A at 24v (or 8.74W) for that setup?
You need to account for transmission and conversion loses. (No, I don't know how much)

Re: 433ah current draw

Posted: Sat Jun 06, 2009 7:29 am
by roc-noc.com
You will see a 1 or 2 volt drop over a long POE cable run on a 24 volt system. So we are talking 4% to 8%. That is less than 1 watt of loss. The conversion loss is already accounted for.

Tom

Re: 433ah current draw

Posted: Sat Jun 06, 2009 9:27 am
by RK
You will see a 1 or 2 volt drop over a long POE cable run on a 24 volt system. So we are talking 4% to 8%. That is less than 1 watt of loss. The conversion loss is already accounted for.

Tom
During idle, my RB433AH with two R5H cards on a long POE run is reporting 19.7V from a 24V POE supply.
That's much worse than 1 or 2 volt.

Re: 433ah current draw

Posted: Sun Jun 07, 2009 12:29 am
by roc-noc.com
How long is your ethernet run?

Tom

Re: 433ah current draw

Posted: Sun Jun 07, 2009 9:45 am
by RK
How long is your ethernet run?

Tom
300 to 400 feet

Re: 433ah current draw

Posted: Tue Jul 07, 2009 12:12 am
by iam8up
1) "Despite the stricter performance specifications, Cat 5e cable does not enable longer cable distances for Ethernet networks: cables are still limited to a maximum of 100 m (328 ft) in length"
http://en.wikipedia.org/wiki/Category_5 ... ategory_5e

2) http://blog.fosketts.net/toolbox/power- ... alculator/

Re: 433ah current draw

Posted: Tue Jul 07, 2009 2:47 am
by InoX
I have regular cat5e cables up to 180m and working...with cat6 SFTP up to 250m

Re: 433ah current draw

Posted: Wed Jul 21, 2010 12:09 am
by wifi45
InoX - what speeds are you getting on those long runs? Also what voltage POE are you using?

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