My experience with two 24VDC power supplies in series (like inside a CTM2) is
that if one of them dies, the 48V drops to 24V.
Is this a DC site with batteries? Will the SAF POE accept up to 60V? If so,
maybe build the site for 48V and downconvert to 24V for stuff that needs 24V.
That also eliminates any worries about 24V equipment that might get fried by
30V.
From: Josh Reynolds via Af
Sent: Friday, November 07, 2014 4:15 PM
To: af@afmug.com
Subject: Re: [AFMUG] dc-dc step up / power supply
Well, here's a question...
If one of those dies in-line, will it fry my SAF POE? :)
Josh Reynolds, Chief Information Officer
SPITwSPOTS, www.spitwspots.com
On 11/07/2014 01:10 PM, Ken Hohhof via Af wrote:
The RSD-200B-48 will definitely work, but it’s not DIN rail.
The TL 060-124 DC is DIN rail, and I don’t see why you couldn’t stack its
output on top of your existing +24 to get +48. I haven’t actually done it
though. The input/output isolation spec is 1500V so you wouldn’t be violating
any specs. The wiring might confuse somebody working on the equipment later.
I have used the TL 060-124 DC a bunch of places, like to get regulated 24V (for
fussy devices) from battery 24V, or to down convert 48V to 24V. It’s useful in
enough situations that you can stock a few and not feel it’s an odd item you
will never use again.
From: Josh Reynolds via Af
Sent: Friday, November 07, 2014 4:03 PM
To: af@afmug.com
Subject: Re: [AFMUG] dc-dc step up / power supply
+24/+48
Josh Reynolds, Chief Information Officer
SPITwSPOTS, www.spitwspots.com
On 11/07/2014 01:01 PM, Ken Hohhof via Af wrote:
+24 to +48? or +24 to –48?
Dumb question, if it’s +24 to +48, would it be kosher to use a 24V to 24V
converter with isolated input/output and connect the negative output terminal
to +24 so they are in series? Seems like this would improve efficiency and cut
the power requirement in half, so that a 60W Traco should be adequate.
http://www.alliedelec.com/images/products/datasheets/bm/Traco/70062693.pdf
From: George Skorup (Cyber Broadcasting) via Af
Sent: Friday, November 07, 2014 3:50 PM
To: af@afmug.com
Subject: Re: [AFMUG] dc-dc step up / power supply
I would not use the SD. Get an RSD instead.
On 11/7/2014 3:46 PM, Ty Featherling via Af wrote:
24V - 48V DC/DC converter 200W SD-200B-48 Meanwell
https://www.jameco.com/webapp/wcs/stores/servlet/Product_10001_10001_1953911_-1
This is from my parts list. More than you are asking for and about $80
but I bet you can look at others in that series to find a better fit.
-Ty
On Fri, Nov 7, 2014 at 3:35 PM, Josh Reynolds via Af <af@afmug.com> wrote:
Need some part numbers for cheap 24VDC -> 48VDC ~72W din mount
step-up/power supplies.
Throw some part numbers out there :)
--
Josh Reynolds, Chief Information Officer
SPITwSPOTS, www.spitwspots.com
