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Hi all

After adding some extra gear (NanoSwitch and 3 radios) to a port on a WS-6-MINI, the wattage was approaching its 18W maximum so I decided to swap in a WS-12-250-AC because the data sheet says it can do 24V at an amp. However, the GUI shows only 0.75A is available. Am I missing something please?

I can't add the radios on separate ports because they're fairly remote and running several more cables isn't practical.

Thanks
Glenn

If you want to push more amps over one cable to feed multiple radios, the Netonix way is to power the WS-6-MINI with 48VH and then power upto 5 devices with the MINI. Unlike the MINI that can be powered over 4-pair at 50V, the N-SW can only be powered over 2-pair at 24V so you are limited by what you can push over 2-pairs. The Netonix ports are spec'd as .75A over 2-pairs because polyfuses being thermal devices are affected by temperature.

Thanks for the fast reply! We initially did what you suggest, i.e. power one Mini from another, but the port would fire up to 1G and then immediately drop out, and repeat. The 75m cable tested fine with a Fluke but we ended up swapping out the 'slave' Mini with a Nanoswitch and it then worked at 1G. However, Mini showed instability later in the day, presumably due to the port taking too much power (the switch stopped passing traffic or responding to pings).

So can you confirm the datasheet is wrong? Are there any Netonix switches available which can push 1A at 24V or should we re-think the topology? Thanks for your advice.

** Edit, the 1G 'bounce' problem resurfaced when we swapped the Mini for the WS-12-250-AC, hence we had to force it to 100 Mbps as shown in the screenshot. I don't know what the problem is there. Maybe there is a subtle cable issue not shown by the Fluke test.

I will leave it to Dave or Chris to address the discrepancy between the spec sheet and what the webUI shows. AFAIK the most you should push over 2-pairs is 1A.

I would not power one MINI from another MINI if the second MINI needs high watts. I don't know what you are using for a power supply but I think the power supply for the MINI is somewhat limited but then I don't know what all you power from the two.

I've got a MINI that is fed via 48VH from a WS24 and it has stood up well for years under heavy load.

Thanks - good to know. We're using a 48VH airFiber PoE injector as the power source.

1A over 2 pairs sounds a sensible maximum. I might try a WS-12-250-DC and see if that can hit it.

Glenn

Banana Jack wrote:So can you confirm the datasheet is wrong? Are there any Netonix switches available which can push 1A at 24V or should we re-think the topology? Thanks for your advice.

We rate our ports as follows:

24V and 48V @ .75A "constant" draw with spikes up to 1A over 2 pair in an environment of 55C. If the switch is in a cooler environment it will push 1A or more but that the limit of the Ethernet Transformer which is 1A per pair (keep in mind 1A positive on 1 pair and 1A negative on the other pair). In fact I am unaware of "any" Ethernet Transformer rated at more than 1A per pair and we have looked a lot no one makes one.

24VH and 48VH @ 1.5A "constant" draw with spikes up to 2A spread across 4 pair in an environment of 55C. If the switch is in a cooler environment it will push 2A spread across 4 pair (2A of positive, 1A per pair on 2 pair, and 2A of negative, 1A per pair on 2 pair) but again that is the limit of the Ethernet Transformer of 1A per pair.

Since we use Polyfuses to protect against fire in the event of shorts but the Polyfuse are affected by temperature it takes more current in cooler temps to open up the circuit and they are "slow" which is why the Polyfuse works fine to protect against fires it does little to protect the switch itself from shorts and a shorted cable can damage the switch as it fried the Transformer and sometimes depending on how the Transformer fries it sometimes damages the switch core.

So in reality our switch will deliver more current per port than the Ethernet Transformer center tap can handle we simply rate it @ .75A per pair "constant" draw because if the switch is setting in an environment of 55 C which is HOT the polyfuse is sized to pass .75A at that temperature.

Thanks Sirhc, that's very useful. I guess the GUI is 'underselling' the switch capability a little bit, but best exceed expectations than struggle to meet them in extreme (hot) conditions.

Glenn