Turning off PoE before connecting/disconnecting

[Paul-ion]

Hello!

I was introduced to Netonix by LinITX in the UK. They recommended the WISP WS-12-250-AC for our project.

In the box was a notice warning about turning off PoE on the ports before plugging and unplugging cables.

We have previously used Cisco SG300 and UniFi switches which do not have that warning and we are able to plug/unplug cables at will without any damage occurring.

My question is, is there something specific about the Netonix switch design that makes damage more likely or is this a general warning?

I'm keen to avoid damage to the switches so I need to ensure if the risk is higher that engineers know the correct procedure and warning labels are in place.

Cheers,
Paul

[wisphopefull]

I'm also wondering this since you can plug / unplug without issue on Toughswitches.

[Dave]

of course you can plug in live POE power ports if you want to, but why?? it is better to plug in un-powered port first, so then our cable diagnostics can check
to see if their is a short on cable before you apply POE power & blow up the switch.

a good, safe, common sense practice is to plug in without power off. it just makes more sense.

but if you want to live on the edge, you can plug in devices live as much as you want to.

[sirhc]

This has been answered several times on the forum, there is a search box on the forums to find answers to common questions:
ADVANCED SEARCH WORDS USED: +POE +plug +live +port
ADVANCED SEARCH USER POSTS: sirhc

I did a quick search and found these post and more:
viewtopic.php?f=17&t=1125&p=8803&hilit=+plug+live+poe#p8803
viewtopic.php?f=17&t=1125&p=8799&hilit=+plug+live+poe#p8799
viewtopic.php?f=6&t=1126&p=8391&hilit=+plug+live+poe#p8391
viewtopic.php?f=17&t=1125&p=8374&hilit=+plug+live+poe#p8374

Using the search box first helps prevent us from answering the same questions 10 times. Everyone likes that we try to respond to posts fast and even let people call us if need be but if we spend half the day answering the same questions over and over again then this will be less frequent and answers will take days not hours. I ignored this post at first as I knew it was answered MANY TIMES ALREADY and was hoping you guys would use the SEARCH BOX first. Answering this post took 20 minutes out of my day and it had already been answered many times. Look I like helping people but I only have so much time in a day. If you assume an 8 hour day *laughs* then this post took 5% of my time today.

Does a ToughSWITCH provide 48VH with 1.5A of power @ 55C - NO
Does a ToughSWITCH provide 48V with .75A @ 55C - NO

Our switches are "passive" POE which means if POE is enabled on a port the power is live so if you plug in a cable that is shorted or the piece of equipment is bad you will damage the port in the switch and this damage is not covered under warranty.

You own the switch, you can power it up under water if you want to but do not expect that to be covered under warranty same as shorted ports are NOT covered under warranty.

Look, to be able to deliver .75A and 1.5A @ 55C we have to size the Polyfuse to not trip while delivering those watts at that temperature which means if the switch is in an environment that is less than 55C the Polyfuse will not trip until way beyond that level. The Polyfuses are used more for fire protection from the result of a dead short and since you can not find Ethernet Transformers to handle more than 1A per pair this means that the chances are extremely high that plugging in a shorted cable or bad device to a live port will result in the damaging of the port and it will cost you money.

You can not compare our switches to "active" POE switches which means that power is applied once the switch negotiates with the device and at that point the switch knows the cabling is not shorted and applies power. The problem with "active" POE switches is 802.3af limits you to 15W and 802.3at limits you to 25W which will not power things like airFIBER radios or deliver 1.5A to a MINI switch.

Look there is a warning on every step ladder that tells you NOT to use the top step but many people do including me but since they tell you/me not to they are not liable for your/my stupidity in the event you/I fall.

I have been a WISP for over 20 years now and I KNOW that we all make mistakes and crimp ends wrong from time to time and we are sometimes in a rush and plug the connectors in without being careful they are straight.

If you turn POE on after you plug in the cable the switch will attempt to determine if there is a cross-short and prevent you from making a mistake if you leave POE SMART enabled. POE SMART is not perfect but it catches 99% of the problems and saves a lot of switch ports.

If you turn the POE on after you plug the cable in the connector is firmly seated and straight with no chance of crossing pins and shorting out your port and possibly damaging your device.

Also there is a possibility that when you plug in a shorted cable or one with a bad device that too much power is drawn and can cause your switch to not only damage a port but reboot the switch causing your tower to go down while the reboot is in progress.

Plug a shorted cable into our switch and MOST times you fry that port and the rest of the switch is fine and will continue to operate. Do that to a ToughSWITCH and most times the whole switch ios dead, at least that has been my experience at my WISP over the years. Feel free to try it yourself.

If you want to plug cables into live ports it is your switch do as you want as this damage is easy to spot when you RMA it and we will not fix it for free.

[Paul-ion]

Thank you for your detailed response and taking the time to respond.

I did attempt to search the forum before posting but could not find the information I needed. Perhaps I used different terms to you, I can't remember the exact phrase I used.

Whilst I appreciate the detail, you could omit the sarcasm. It does not give a good impression of your company. This is my first experience with Netonix products. As an introduction to this community, it's not a great experience so far. You might want to re-read your post and see how unwelcome it might make someone feel.

I've been a network engineer for almost 20 years, only the last few in WISP, and I've not seen any of the failures you talk about.

I was seeking to understand more about the differences between Netonix and other vendors and why we should take such precautions. I do now understand more fully. Thank you again.

Perhaps these common questions could be a sticky post at the top of the relevant forum section. That way people could read through before posting/searching.

Enjoy the rest of your day!

[sirhc]

Thank you for your detailed response and taking the time to respond.

I did attempt to search the forum before posting but could not find the information I needed. Perhaps I used different terms to you, I can't remember the exact phrase I used.

Whilst I appreciate the detail, you could omit the sarcasm. It does not give a good impression of your company. This is my first experience with Netonix products. As an introduction to this community, it's not a great experience so far. You might want to re-read your post and see how unwelcome it might make someone feel.

I've been a network engineer for almost 20 years, only the last few in WISP, and I've not seen any of the failures you talk about.

I was seeking to understand more about the differences between Netonix and other vendors and why we should take such precautions. I do now understand more fully. Thank you again.

Perhaps these common questions could be a sticky post at the top of the relevant forum section. That way people could read through before posting/searching.

Enjoy the rest of your day!

All I can say is that is me, I shoot straight and speak my mind, sorry if you do not like a person that is frank and to the point, I do not mean to offend but rather express my dismay at answering repeated questions.

My all time favorite question asked MANY times: "Can we disconnect the fans?"

My answer: "Yes we decide when to turn the fans on and off based on the tea leaf patterns at the bottom of a salad shooter. The fans were really not needed anyway we just added them for fun."

DO NOT WORRY YOUR NOT ALONE, MY WIFE AND KIDS ARE ON YOUR TEAM AND WOULD AGREE WITH YOU, THEY CALL ME A JERK AT LEAST ONCE A DAY.

I added it to the end of this Annoucement post as you suggested: viewtopic.php?f=6&t=1178&p=8809#p8809
Read the question and answers at the bottom of post #1

[sakita]

Seems to me the biggest misunderstanding is folks not knowing the difference between an active vs passive PoE switch (i.e. what does 802.3af/at actually do compared to what a typical passive switch doesn't do).

The PoE smart feature is really genius since it really does improve the situation providing a substitute for 802.3af/at functionality that passive devices don't have.

Likewise it is interesting that in the US we plug in 120V cords live all the time whereas in the UK they have an on / off switch right next to the outlet. Then again, there is also a few other big differences between their electrical circuitry and ours... point being there are often very good engineering reasons for things even if the user never understands them.

As for sarcasm, at least you have a personality and Netonix isn't caught up in being kinder-gentler and PC (although I don't know what your bathroom policy is) Maybe it's an acquired taste but I prefer zesty to bland... and maybe you are toning it down a bit but one can only answer the same question so many times without getting a bit snippy.