Best solar voltage for pmp450 and epmp equipped tower

Sorry if this is the wrong area to post this thread, but i couldn’t figure out where else to post it, but here is my question. We will be running our new tower on Solar. We will have both epmp and pmp450 radios on it and even a pmp820. We will use an inverter to use AC power. The question is, is there any significant differences or advantages between using a 24volt system vs a 48 volt system? Thank you

Since you are running mixed equipment (i.e. various products, some of which require 30 VDC input, and others that require 48-56 VDC input), I would recommend using a 48 Volt system.

You're going to need some DC-DC converter somewhere, and most of these can take 48 VDC input and output 30 VDC or other voltages as needed.

With a 48 Volt system, you can use some of the 802.3af/at compliant devices without any conversion.

Just my opinion.


Great! Thank you for your input. It us much appreciated and it looks like 48v is what we will go with.

I'd suggest skipping the inverter as much as possible too.  

A) Efficiency is lost, and you need more battery to make up for it

B) It's one more thing to go wrong.

C) Added cost!  (Don't go cheap if you absolutely must have an inverter on site.)

We operate several 24v and 48v sites.  We started out with inverters and pulled them all from continuous duty years ago - keeping some around strictly for on-site use like charging laptops and stuff.  48v is definitely the future too and probably our next big conversion as most of our sites are still 24v.

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If Cambium needs 30VDC, what product can you recommend to convert the 48VDC from the solar power system to 30VDC PoE injection that Cambium needs?

I can’t recall if we have any 48 to 24 (canopy) POE’s in service, typically when we lifted sites to 48v, the hardware was also changed to 48 native (eg., 450i etc). I think though, we had a couple of 48 to 24 for non-canopy devices (beware - canopy 24v devices use a different polarity than most other 24v poe devices). I think those ones were made by Tycon, who if you’re just doing power, would be the first one I’d go to.

You could ask the fine folks at Packetflux too, something like the RackInjector I think can take in 48v and down convert to 24 canopy with the right modules.