Burned PSUs

[ehsab]

Hi,
I've had my first Netonix Switches die on me.
They died with a couple of days between them, both with burned PSUs.

Both of them was on UPSes.

I'd like to see if someone might tell me from the pictures if it could be problems from the AC side or the DC side (ports).

Backside of PSU1

https://imgur.com/OaGXNfH

Frontside of PSU1

https://imgur.com/jB4c1Gs

Backside of PSU2

https://imgur.com/PlhZnLX


Kind Regards
ehsab

[sirhc]

That type of damage is from the AC power source and or came in the AC ground from poor grounding.

My bet is the switchboard is probably OK.

Test the switch board with a 48V DC power source and take it through the Bench Test as described here: viewtopic.php?f=6&t=2780#p19221

Next time please upload your pictures as described in my post footer.
To upload pictures click the Upload attachment link below the BLUE SUBMIT BUTTON.

[ehsab]

Hi,
Thank you for quick answer.
What happend in the PSU due to poor grounding? Seems like the burned area is on different places.

Is it possible to buy PSUs separetly, if the switchboard is ok?

Kind Regards

[sirhc]

What I mean by poor grounding is if the the electrical service ground rods are insufficient and a surge comes into the electrical service everything with a surge protector or similar circuitry tries to shunt that excess current to the ground and there is a ground plug on the AC cord so that ground current can actually come into the power supply from the ground plug trying to get to the tower ground through the switch through the Ethernet cable to the device on the tower through the tower to the tower ground rods but the power supply tries to isolate DC output from Earth ground and poof.

Often when the power supply is damaged from a surge it does not damage the switch board....NOT A GUARRANTEE

WHich is why I suggested you test the switch board with either another power supply from another WISP Switch of same model or carefully provide 48V to the board connector then BENCH TEST IT as explain in the link I provided above.


99% of all WISP equipment damage is from ground current (I own a WISP)

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.