How do I minimize the power drain of an outdoor AP?

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Any ideas for how to minimise the power drain of an outdoor AP used as a repeater which is solar powered.?
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Gordon

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Posted 5 years ago

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Adam Conway

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The biggest drain is that the heater kicks on around 0 degrees C. Maybe mount it closer to the equator? :) Seriously though, the heater is the biggest power draw.
Best,
AC
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Gordon

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Is this able to be turned off in the software ? And what are the consequences if this is done should the temperature drop below zero (condensation damaging the unit ? or just stops and can restart when temperature rises ?.)

I understand from queries through your agent that the power consumption of an AP is around 7 watts, and in my solution for the customer have to consider if i should use Aerohive or relatively dumb (but low power) Wifi repeaters

I understand there a few case examples for Solar powered Aerohive installations in temperate climate regions
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Adam Conway

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This has high powered radios in it, the risk is that as temperature goes down the PA's resistance will go down and can overdrive both the power supply and the PAs and damage the unit.

Any outdoor unit that has high powered radios has this limitation so the question for you is how important is this link?
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Gordon

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The location of the solar/battery powered AP's (acting as repeaters) is up on the plateau, so temperates can drop to around zero in Winter at night in fine weather.

How many watts are consumed with and without the heater please. Can the AP170 work with lower power to PA's ?

Thanks and Regards
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Adam Conway

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Sorry for the delay, trying to get more precise info
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Adam Conway

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Okay, We are going to get you some exact measurements, however I did learn something. In general the heater is only used to "cold start" the AP. For example, if the AP loses power and gets cold when the temp is below 0 C the heater will kick on to bring it up to temp. While operating the heater rarely kicks on even if it drops below zero - except in extreme circumstances like this: http://blogs.aerohive.com/blog/the-by...
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Dave Brown

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Interesting, I was unaware there was a heater inside the AP170's. Whats the actual temperature profile where the heater might kick on?

As an FYI, that extreme deployment you linked to Adam, is my AP. As of this morning, its -44F outside and the AP is alive and kicking.
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Adam Conway

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That is great! Dare I ask where you found temperatures like that? Yeah even industrial components only go down to -20 C, for cold starts (I believe below zero) we kick on the heater before turning on the AP. Not all outdoor APs have heaters, but the good ones do.

By the way, it was +40 degrees C when I woke this morning and I was cold - but California has made me soft. :)
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Dave Brown

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Interior Alaska. I'm about 130 miles out of Fairbanks.

So normally the heater only kicks on on a cold start to bring the interior of the AP up to safe temps? It doesn't turn on at any other time? I talked with Gordon @ Aerohive before I deployed it and his thinking was that so long as the AP remained powered it should have no issues...the weak link would be the power injector or in our case the PoE switch powering it.

It actually warmed up to -16F this morning, but with the 30mph windchill it feels like about -47. Having to head out to one of my remote comm rooms this morning was not pleasant even with all my cold weather gear.
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Adam Conway

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Normally yes, but at your temps it might kick on more. I cannot say for certain because I personally haven't checked this. We are doing some testing to check this behavior this week though.

So you are the extreme AP guy from the blog post, huh?
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Dave Brown

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I'd be interested to see what your tests show. If you need logs from me I can provide them. Right now I've only got the one(dozens of 340s and 350s though), but if it tests out well this winter I have plans for several more AP170s.

Yes I am. That AP originally was intended as a summer use item, but the plan grew and morphed and its still in place.