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Re: Increase the on board 24V power supply capacity

Posted: Mon Sep 24, 2018 10:33 pm
by sirhc
No, if you open the chassis and the while "silkscreen" on the PCB says PCB Rev H or I then you do not need to perform the modification.

Ignore the CFG white box which will have an F or lower letter in it.

Hardware revisions incremented more than software changes need to happen so the current PCB Rev is I yet the UI will report Rev F.

Re: Increase the on board 24V power supply capacity

Posted: Tue Sep 25, 2018 7:34 pm
by beambarossa
Fully understand this - i hope you guys look at coding this in one day possibly as this is a massive effort to go to each site out of hours to open up and inspect. It has caused us many headaches already and we have about another 30 switches to check it will take months.

Re: Increase the on board 24V power supply capacity

Posted: Thu Jan 31, 2019 10:12 am
by sbyrd
So I did the mod on one of my WS-12-250 switches. My soldering skills are not the best but I think I got it right. How would I know that it is working properly?

IMG_20190131_090003885.jpg

Re: Increase the on board 24V power supply capacity

Posted: Thu Jan 31, 2019 11:11 am
by sirhc
If you have some test equipment such as load generators you could test being careful not to load more than .75A per port, but as long as your soldering is OK should be fine.

On your next unit make sure wire is at least 24 AWG and make it a little shorter if possible.

I would also do the ground MOD while your at it on older units.
viewtopic.php?f=17&t=2584#p18081

Re: Increase the on board 24V power supply capacity

Posted: Thu Jan 31, 2019 11:36 am
by sbyrd
I can remove the wire if you think it is a problem. Also I knew you wanted 24AWG so I saw on the boxes of Ethernet cable I have it says 24AWG so I assumed each wire was 24 AWG. Is this not the case?

Also should I not trust my work on this one can I still get this RMA'd and modded by you guys for the ~$50 charge?

Re: Increase the on board 24V power supply capacity

Posted: Thu Jan 31, 2019 11:42 am
by sirhc
sbyrd wrote:I can remove the wire if you think it is a problem. Also I knew you wanted 24AWG so I saw on the boxes of Ethernet cable I have it says 24AWG so I assumed each wire was 24 AWG. Is this not the case?


No, it looks like it will work provided your solder connections are good.
All I said was make sure it is 24 AWG or heavier.
I also said next time you do it try and make sure the wire is a bit shorter if possible.

And finally I said while your at it you could have done the GROUND MOD maybe?

Re: Increase the on board 24V power supply capacity

Posted: Sat Feb 08, 2020 7:15 am
by bpnz
I have quite a few of the WS-12-250-DC switches. Some of them have a pretty high load on them, but that's because of 48v AirFibres connected.

I just looked at my heaviest load one, it sits about 167w (25v).

The 24v radios on it only total about 30w, the balance is made up with 48v air fibres and a POE camera.

The other stats on the the switch are ->

Firmware 1.5.5
Board Rev F
Power Supply Firmware 70
Power Supply Board Rev B

It would be at least two, maybe even three years old.

Not to sound dumb, but I just want to confirm, do I only need to worry about the total 24v POE loading, or the combined 24v / 48v loading?

Thanks

Re: Increase the on board 24V power supply capacity

Posted: Sat Feb 08, 2020 9:11 am
by Dave
you only have to consider the 24V loading, no issues with 48V.

Re: Increase the on board 24V power supply capacity

Posted: Sat Feb 08, 2020 9:14 am
by bpnz
Thanks Dave, reading the thread I was pretty sure that was the case, but due to the importance of it just wanted to make sure. I’ve currently got the switch I mentioned above away for RMA repair with your guys (have a spare in place) and as I’m not sure what caused it to fail I did wonder if it was potentially power..

Re: Increase the on board 24V power supply capacity

Posted: Sat Feb 08, 2020 11:43 am
by Dave
I just re-read you post..that is way to much power on the 25 volt rail...you will have issues for sure.....167 watts steady state is pushing it, because it will peak well beyond that.