DC Switch WS-8-250-DC ethernet up and down

[kbloch]

I have a DC switch model WS-8-250-DC that fails to boot, ethernet links go up and down when installed at a radio site. Switch works fine when at the office. Cant even log into switch to get log information as it fails to work.

Have tried two different power supplies.

Have tried running from battery only.

Have tried both grounding and not grounding the switch.

Have tried running from a vehicle inverter.


My guess would be that RF interference is causing issues with the switch and preventing it from working. Site is a highly loaded site and includes broadcast TV and radio stations, cell towers, microwave, VHF and UHF voice radio, paging etc.

[Dave]

hmm, this is a different one for sure...as a test, can you shield the switch some how?

[kbloch]

No there is no way to shield the switch.

[Dave]

ok, lets think about this, do you have it pre-configured to power up ports already? lets see if it will power up with just your uplink port & nothing else plugged into it.

[Dave]

and is this a positive power environment, or -48 volts, where everything on the POE negative side is earth grounded?

[Dave]

and if the switch can boot up with only the uplink port attached, please run make sure that all POE power is turned off on all ports & run our cable diagnostics before applying power.

[kbloch]

This radio site has experienced numerous power failures that have lasted for up to 48 hours. Due to the power failures we have installed four deep cycle batteries with the intent of having everything run on DC power to provide for a long enough battery backup when power fails.

At the site at this time a Toughswitch is powering two Rocket AC PTP radios and it is not having any issues. It is being powered by AC power and has no backup.

The Netonix DC switch was installed and connected to the battery bank and powered on. Ports 3 and 4 had been setup in the office to provide 24 volt POE output. The Rocket Ac radios were left connected to the Toughswitch until we had everything up and running then we were going to move the two ethernet cables to the Netonix switch. While trying to verify that everything was working all we saw was the port on the Netonix switch that is connected to the Toughswitch go up and down about every six seconds or so. We tried power cycling the Netonix switch several times to see if it would be stable and it never would function. We repositioned the switch inside the shelter several times and it would not work. We turned off and unplugged the battery charger to see if the problem was related to the AC power and it did not work. We uninstalled the switch from the site and took it to my vehicle and connected the power supply that was used to setup in the office and it still would not work.

The only thing that worked was to drive away from the radio site by about half a mile and then everything worked. The problem appears to be that the switch does not have sufficient shielding to work at a large radio site with multiple transmitters.

Yes it is a positive 12 volts DC power. As stated ports with POE enabled did not have any equipment connected.

[sirhc]

I am not sure what you are calling a heavy transmission site?

There are over 1,000 DC switches in the field now working fine at transmission sites?

There are over 5,000 AC switches in the field all working fine at transmission sites?

It is not like this is a prototype and you have the only one, could this unit be defective...possibly, not sure?

Our switches were tested and passed FCC testing to NOT transmit too much interference and to work properly in a certain level of interference.

Since this is a DC site you did hook up the Chassis Earth Ground Lug correct?

The chassis does need to be hooked to Earth ground for the metal shielding to work properly and to make the ESD cabling something more than a placebo.

If you like you can email me at chris@netonix.com and we can get it back on RMA and test it out or you can do some more testing and see what you find.

[kbloch]

And as far as how high the interference might be I did an FCC license search and used geolocation for the site with a 2 km radius (the site is four miles from anything) and the results were 449 active licenses at that location. There are about a dozen buildings and towers on this mountain. I could at least 10 FM radio stations plus all of the local TV stations, cellular, railroad, city and county governments, FAA and hundreds of business customers. Many of the business customers will be on trunked radio systems which will transmit 24/7.

I will send you an email later about an RMA of the switch.

[sirhc]

and is this a positive power environment, or -48 volts, where everything on the POE negative side is earth grounded?

Since this is a DC site you did hook up the Chassis Earth Ground Lug correct?
The chassis does need to be hooked to Earth ground for the metal shielding to work properly and to make the ESD cabling something more than a placebo.

It is hard to help you when you skip questions.

The DC Earth Ground Lug relates to your theory of a HIGH Transmission site and possible noise interference.

If the Earth Ground lug is not hooked up with a DC switch then the metal shielding is all but useless as the switch has no path to Ground for the chassis shielding and the ESD RJ-45 jacks.

Dave's question was also not answered.