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What happens in Overload Situation?

I really like the form factor of the edgepower, and the power monitoring, but most of our sites are running 3 or 4 Airfiber radios.  Power draw at any of our sites is >150w.  I haven't have the nerve to test it, but what happens if one of the 150 modules shutsdown with a load >150w.  Does the other Power supply shutdown as well?  Does anything get damaged?

 

I'd really like to see Individual 300w PS units, for true redundancy. 

 

Nate

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Re: What happens in Overload Situation?

Maybe I'm wrong, but I thought that if you had both 150 power supplies turned on that the EdgePower will use both of them for a total of 300 watts.

 

From the manual:

"A secondary PSU module bay is available for reserving a hot-swappable backup PSU or for increasing the DC output power to 300W"

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Re: What happens in Overload Situation?

Yes, 2 150w Power module units in parallel for a total of 300 watts.  But if you have more than 150w of Draw, what happens when one of the 150W PSU units fails. 

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Re: What happens in Overload Situation?

[ Edited ]

Running any power system above 80% of it's max rating is always a Bad Idea.   For out big sites we run multiple redundant EdgePowers with a combination of AC and DC power modules, or (for very big sites) all DC modules with outboard chargers for the 48V battery stacks.   

 

And you never never run past your " what if the redundant units fail?" numbers - this is why Data Centers limit you to less than 50% power draw on each A/B dual rail circuit (the really good ones will alarm if you use more than 8A on a 20A circuit), so that when one rail/UPS fails it doesn't overload the other and shut down everything.   You need to carefully engineer all this so that things never get overloaded because they will then shut down or be damaged.   We are looking at main charger units for really big sites capable of 8000 wats total capacity now with N+1 redundancy so things never go down...

 

And to answer the OP question, I have actually (accidentally) shorted out the Edgepower's output and it just folds back to 0 output.   So it won't damage the unit but it won't power anything either if you go over 150 watts draw on a module.

Jim

" How can anyone trust Scientists? If new evidence comes along, they change their minds! " Politician's joke (sort of...)
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Re: What happens in Overload Situation?

[ Edited ]

I would specify one EdgePower per AirFiber radio in your application.  That provides the additional benefit of remote power management.

 

UBNT- a -48VDC plant based on telecom batteries and a hopped-up EdgePower would be a killer product.

 

And finally give you the chance to standardize on 48v.

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Re: What happens in Overload Situation?


@bcannon wrote:

I would specify one EdgePower per AirFiber radio.


Uh, that's a little overkill, even in an AC + DC design where the EP can only supply 150 watts - and that's assuming you mean the big AF radios that pull 35-50 watts each, not AF-X or XHDs which only pull 10.5 and around 6 watts each respectively.   I have a number of sites with 2 EdgePowers running 3 big AF radios and they work just fine that way...

Jim

" How can anyone trust Scientists? If new evidence comes along, they change their minds! " Politician's joke (sort of...)
"Humans are allergic to change..They love to say, ‘We’ve always done it this way.’ I try to fight that. "Admiral Grace Hopper, USN, Computer Scientist
":It's not Rocket Science! - Oh wait, Actually it is... "NASA bumper sticker
":The biggest problem in tech I see right now is that most users don't want to do things that are hard. That doesn't bode well for the industry or the society.": (me. actually ;-)
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Re: What happens in Overload Situation?

I'm certain an Edge Power can supply power to 3 even big dual dish AF radios. It would probably be fine even overloaded as I'm sure UBNT designed redundancy in.

But in my eyes you don't buy a dual PSU device to have lots of failure points. So you don't overload your gear beyond 80% NEC maximum of max output or branch circuit continuous rating. In our datacenter, we don't go over 40% because everything is A & B power.

That limits his application to at most 4 large AF radios, for redundancy during a PSU failure.

Most dual PSU devices manage this for us, but UBNT gave us the option of giving up N+1 for twice the output power rating (300w). Your A&B max draw (all I would ever tell you is safe for lifesaving operations) is 120watts. 3 large AFs. Max.

Finally, an individual AF per EP gives you the ability to remotely manage power, which is probably the real need in a tower like this.
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