Forrest, please forgive me for even thinking this thought... but I wonder  how 
much current it takes to blow a phy transformer and how hard it would be to 
have an over current shutdown.  I have done over current shutdowns before and 
have used those over current passive devices that self heal.  Polyfuse I think 
is the name....

Like you need more ideas...

From: Craig House 
Sent: Friday, April 24, 2015 5:26 AM
To: [email protected] 
Subject: Re: [AFMUG] Packet flux question

Thanks Forrest. It was a mix of 450 and 100 series.  They all appear to have 
been damaged.  The only thing I get an Ethernet link light on is a bh50 radio

Sent from my iPhone

On Apr 24, 2015, at 05:06, Forrest Christian (List Account) 
<[email protected]> wrote:


  Hmm.. I love (not) autocorrect on android... port, not portal...  But now I'm 
on a real computer and have a chance to re-read the original message, and think 
a bit... I think I need to change my final answer.


  If these were 100 series radios I'd say "that seems rather odd that this 
would cause a failure".   BUT...  I'm assuming these are 450 radios.


  With the 450, there's a ethernet transformer on each pair.  To DC, this is 
effectively a short.   Or since these are made with very thin wire you could 
probably more accurately call it a 'fuse'.   So if you take a pair and put say 
the + lead of a 24V power source on one wire in the pair, and the return (-) on 
the other pair, you'd find that the wire in the transformer would melt, and 
would probably do so very quickly.  This is *exactly* the wiring that the 
320/430 radios used.  In addition, there is every possibility that the current 
being drawn before melting is smaller than the amount of current needed by a 
real 320 or 430 radio on power on.   So, when this got plugged in, there's a 
good chance that you melted the ethernet transformers.


  The good news is if this is what has happened, it should be a fairly easy fix 
by almost any electronic repair shop which knows how to rework surface mount 
boards - just remove the magnetics and replace them.   


  Unless of course there was another cause.


  -forrest



  On Thu, Apr 23, 2015 at 9:58 PM, Forrest Christian (List Account) 
<[email protected]> wrote:

    Due to the odd wiring the radios probably shorted out the overcurrent 
protection in the injectors, turning off the portal and I'd not be surprised if 
the radios are just fine.   Especially if they were never plugged into an 
already on injector.  

    So we accidentally put sync injectors on to a din rail today that were for 
the 320/430 radios.  Oops 

    Both of the injectors were powered by a 24 V 10 amp power supply
    All of the radios that were plugged into those injectors no longer appear 
to boot up which wouldn't surprise me if there had been a 56 V power supply or 
48 V power supply powering them.  However since they were powered by a 24 V 
power supply how could that have damaged the radios?

    Sent from my iPhone



  -- 

        Forrest Christian CEO, PacketFlux Technologies, Inc.

        Tel: 406-449-3345 | Address: 3577 Countryside Road, Helena, MT 59602
        [email protected] | http://www.packetflux.com

           


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