WS-8-150-DC in rural Nebraska

[cbanzhaf]

We are finally moving to DC. This is our first model. It is a bit rough. Not quite finished. We need to pull the AC power inside and finish connecting the grounds.
This will be powering one Rocket M5, two Powerbridge M5's, and one Nanostation M5.

[sirhc]

Nice looking box.

I Can not tell, is the switch connected directly to the battery bank (in line fuse recommended)?

If switch is connected directly to battery banks just make sure charger is smart multi stage charger with more watts than switch which is 150 watts.

If connected to a power supply / charger bypass device that the power supply is 1.5X the rating of the switch power supply which is 150 watts so 225 watts or more.

I see Ethernet surge suppressor which is not a good idea with "passive" POE devices because how they work is clamp all 8 wires together and to earth ground which is a dead short.

99% of WISP equipment damage is not from surges or ESD but rather ground current which is from insufficient electrical service ground rods and the tower ground rods are a better path to ground and then not bonding tower ground rods to electrical service ground rods.

I have not used an Ethernet Surge Protector in my WISP and I lose less than 1 radio on a tower per year which has been tracked back to grounding modification done on site by municipality that we needed to correct as we are mostly on water tanks.


Here are some good posts on grounding:
viewtopic.php?f=30&t=2786&p=19279#p19279
viewtopic.php?f=30&t=1816
viewtopic.php?f=30&t=188
viewtopic.php?f=17&t=1786&start=30#p13447
viewtopic.php?f=30&t=1429

[cbanzhaf]

We are using a PB-300P-24, so 300 watt. The charger is directly attached battery terminals and so is the switch. There is a 7.5A fuse between the charger and the battery. I debated putting another fuse between the battery and the switch as well. Do you think I should?

[sirhc]

We are using a PB-300P-24, so 300 watt. The charger is directly attached battery terminals and so is the switch. There is a 7.5A fuse between the charger and the battery. I debated putting another fuse between the battery and the switch as well. Do you think I should?

I would use a breaker between battery bank and switch, you need to size it as follow:
9V is the lowest the switch will run
Assume 150 watts (full utilization)
So 150w / 9V = 16.667 Amps
I would then bump up to deal with in-rush so 20A fuse.

The fuse is there mostly for safety to prevent fires in the event all goes wrong.

Personally I like DC breakers which provide a clean way to disconnect power to switch.

https://www.google.com/search?q=20A+dc+ ... 97&bih=542

[cbanzhaf]

I've installed a low voltage disconnect, bottom left of the switch. It disconnects power at 20v. I figured it at 150 / 20. Any type of DC breaker you recommend?

[Chris@edgarhighspeed.com]

if this is a mission critical link, you might want to remove the low voltage disconnect so you can squeeze the last few volts out of the batts. You know like at 3:00 am when you have been up all night.

Since the switch will run right down to 9V

Just a suggestion.

[Patriots15]

I had this same switch connected to a Tycon (TP-SCPOE-1224) POE/Solar Dual Input 12V Battery Charge Control. We had some heat issues in the cabinet from not enough air movement. The switch overheated. For a quick fix, we went to a mini 6, but the downside was we lost the backup battery setup that was attached to the charge controller. Anyway, I replaced out the cabinet with one that had more ventilation. I purchased another ws-8-150. I installed all the components the same way it all was previous to the overheating which ruined the original switch. This time when switch was attached to charge controller the switch got ruined again, and now the switch when powering up has the fan run constantly. I have been searching and learning as much as possible about AC and DC power. I am a noobie to power DC.

I will definitely use a inline fuse the next time I put another switch in.

SIRHC, I used a multimeter to check output off charge controller and it showed 12v. I was wondering if I am missing something here?????

Any info about this setup or advice would be appreciated.

I have a new TP-SCPOE-2424 model I was going to retest a new setup with, but im just not sure if im not understanding something. The switch would power 5 epmp AP's and the 6th port would NOT use poe. It would be used for a temperature probe.

[sirhc]

Well we recommend hooking the SMARTS DC switches DIRECTLY to the battery bank (with an inline fuse or breaker).
SMART DC switches - WS-8-150-DC / WS-12-250-DC / WS-26-500-DC

Then hook your charging system to the batteries.

If you want to use a power supply then use the WS-12-DC and get a 48V power supply.

Also in the picture above you see EThernet Surge protectors which we warn people NOT to use.

Ethernet surge protectors work by clamping all 8 wires together which is a dead short so that will fry the port or the whole switch.

99% of WISP damage is not from surges it is from Ground Current which Suirge protectors do nothing to protect you from.

GROUNDING GROUNDING GROUNDING


99% of all WISP equipment damage is from ground current.
Here are some good posts on grounding:
http://forum.netonix.com/viewtopic.php? ... 279#p19279
http://forum.netonix.com/viewtopic.php?f=30&t=1816
http://forum.netonix.com/viewtopic.php?f=30&t=188
http://forum.netonix.com/viewtopic.php? ... =30#p13447
http://forum.netonix.com/viewtopic.php?f=30&t=1429
Read the posts above but the basics are as follow:

Tower ground rods must be bonded to electrical service ground rods HEAVY #2 wire.
I always add 1 or 2 “new” ground rods to older existing electrical services.
We started repairing other equipment - see here: viewtopic.php?f=21&t=2827#p19482

And we see the EXACT SAME DAMAGE - FROM GROUND CURRENT.

[Patriots15]

I appreciate the advice. The Ethernet surge protector your talking about in pic above. Are they just shielded module jacks from Panduit like the ones I installed in a 8 port patch panel in cabinet?? That was something different I added to this new enclosure that wasn't in the other...

I installed the shielded jacks in this little panel
http://www1.panduit.com/en/product/CDPP8RG

[sirhc]

I appreciate the advice. The Ethernet surge protector your talking about in pic above. Are they just shielded module jacks from Panduit like the ones I installed in a 8 port patch panel in cabinet?? That was something different I added to this new enclosure that wasn't in the other...

I installed the shielded jacks in this little panel
http://www1.panduit.com/en/product/CDPP8RG

Could be, just do not use Surge protectors, spend your money on grounding.

Add a new service ground and make sure tower grounds are bonded to service grounds.