jakematic wrote:What I have is is not atypical from most layouts
I must admit when I said give me a rough drawing maybe I chose my words poorly and you took the words rough to extreme as I can not figure out your previous posted drawing but that is OK we will address below.
jakematic wrote:Is there a ground issue? Maybe. I don't know. I don't want to spend thousands on testers or electricians.
Adding that cost to customer installs is out of the question.
I spent 35 years in a family owned dealership, am now in technical pre-sales, and have a good grasp of what customers will/won't swallow.
There is no need to use electricians but simply understand what NOT to do with Ethernet.
THINGS NOT TO DO:1) Never connect Ethernet devices that are on 2 different Earth Ground Potentials such as having a tower grounding system that is not properly bonded to the electrical ground system. The further the electric service ground rods are from the tower ground rods the heavier the ground bonding cable needs to be or if more than 30 to 50 feet one should opt to only use the Tower Earth Ground system only using the Hot and Neutral from the Electrical service and using the Earth Ground from the tower as described in this post:
viewtopic.php?f=17&t=1786&start=30#p13447 2) Never connect Ethernet devices that are each located on different electrical services or even different sub-panels as they will have different ground potentials and it will try to equalize across your Ethernet cable and switch, in these cases use fiber. This is discussed in this post:
viewtopic.php?f=30&t=18163) Never plug any device onto an Ethernet network that is not AC surge protected as that would be like locking all your doors and windows in your house except the back door before going on vacation. An AC surge can come in on any device and run across the Ethernet network and damage random equipment.
jakematic wrote:Right now I've got 2 dead and 1 dying WS8-150-AC
OK, lets look at the units in play
jakematic wrote:- one back under RMA to be analyzed
I am going to send you your repaired unit (new board installed) back tomorrow and air ship the damaged board to Dave (our Engineer) in Canada for an in-depth analysis to determine what is going on. He can do this much better than I can do here as I do not have the equipment to do such and analysis and this is above my pay grade anyway. Now this unit was exposed to AC without a surge suppressor so it "could" have been damaged by an AC surge?
jakematic wrote:- one I take full responsibility for killing and am waiting on RMA (powered my uplink port on the bench by mistake, fried a port on a Netgear, killed the WS8)
OK this one is most definitely your fault, I will get you an RMA number tomorrow on this to send in for repair.
DO NOT BLAME THE SWITCH FOR THIS ONE. jakematic wrote:- one that is dying in production
This one I would leave run as is and see what happens until we can diagnose the issue on the first unit you sent back.
jakematic wrote:Also have a WS12-250-AC that is chugging along for 3 days with no problems.
So leave this one run as is.
jakematic wrote:And a TS5 that's been in service for several years showing no signs of any issue.
Noted.
jakematic wrote:The only thing that I can come up with is to electrically disconnect the two switches.
To do that I'd put in another WS-12-250-AC, run fibre beween the WS-12s, and pull all the PoE cables back to the new WS-12 thus eliminating a switch.
Does this sound reasonable, and is it the only way forward for other installs ?
Well I could better answer this question if you take the time to make a better drawing and provide details on the Electric service or services at this location.
What that person has in that post is most definitely 2 ground potentials. There is nothing we can do to protect against this behavior and is a common issue when using "any" Ethernet devices not just ours with 2 ground potentials as outlined in this post which is quote from another Engineer from another company preaching the same things I am trying to educate people on:
viewtopic.php?f=30&t=1816jakematic wrote:I can't keep throwing money at this.
Either there is a problem with the WS8, or for residential networks fiber backbone is a better idea, or both.
Dunno, but I'm going to have to run fibre and install another WS12 at this point to replace the dying WS8.
Well I would really like to determine if this is a ground potential issue which would require a better drawing from you and a better explanation of the electrical service or services involved with this setup.
If you make a better drawing maybe using MS Paint and post it and then PM me your cell number I can call you later today and discuss.So what we are looking at as possible causes:1) You do have a ground potential issue here and we will help you find it if possible.
2) We have a faulty component on some of the boards, as it does happen. You get reels of components and some percentage of the components are faulty sometimes which is why we have batch numbers to track this.
3) We are also discussing the possibility of a software issue as we may not be properly sampling/averaging the 3.3V readings but Dave wants to determine if the 3.3V is actually fluctuating once he receives your board and looks at it.