12-250a power supply

[LRL]

Whats the chance I could buy just a couple of spare ac power supplies? Of course I realize any modification voids warranty, but I'm interested in making one redundant power wise.

[sirhc]

We will be offering replacement power supplies on the web store soon

[adairw]

So, can I assume dual hot-swaps are coming soon? :) hehe

[billbuchan]

This doesn't quite address a power supply failure, but I'm using APC Automatic Power transfer switches (with two UPS's) so everything at our core sites is redundant (at least power-wise). Okay, it doesn't address the power supply failure but its a relatively inexpensive way of providing two power lines.

Hope this helps,

---* Bill

[sirhc]

We will soon offer power supplies for sale so that WISPs can have spare power supplies in the even they have a power supply failure. Building a switch with dual redundant hot swappable power supplies will definitely push the price point over what most WISP's would be willing or able to pay for.

You have to remember Ubiquiti uses the same power supply company for their switches as we do which is Gospower in China and even Ubiquiti runs too small of production runs to offset the costs of such custom power plants let alone little tiny Netonix.

As Ubiquiti branches more and more into the IT market their buying power may offset/change this but for us I do not see how.

But there is a reason UBNT does not even attempt this, at least yet?

For hot swappable power supplies the power supplies have to have additional logic and circuits plus they would require their own removable chassis and fans as well as a slip in connection. All these things add up to a LOT of additional costs.

I am not sure about UBNT's costs but for us to pay for a custom design power supply with chassis and get them certified would be extremely expensive and or we would have to commit to purchase 100's of thousands to get the manufacturer to absorb the costs.

Plus to give you an idea we plan to sale power supplies as spares for around $99.95 each, so image if we had to add the additional logic/circuits, custom chassis and their own fans, then the switch chassis becomes more complex/expensive because it has to have a sort of rail system to accept the power supplies, then their is the design fees and certifications.

If a power supply fails and you have a spare on hand the time to swap it out is only a few minutes. I am a small WISP with about 17 or so switches in service now that I have 24 ports switches and only need one per tower but even so if you said the cost for a switch with dual power supplies would be $500 more that means $8500 more...I can not afford that for my WISP. Yes a switch power supply failure is a major pain in the ass and people bitch but $8500 would be almost 2% of annual gross income of my WISP.

What we do is design our stuff around existing power supplies already out there with a few changes as possible so we can piggyback on existing LARGE productions runs of the manufacturer.

Yes there are power supplies out there for computers that available but they are totally the wrong voltages (3.3V, 5V, 12V) needed for POE switches so they would need completely redesigned anyway and their connectors are totally wrong with much lower amperage capacity needed for POE switches.

So unless people want to pay several hundred dollars more per switch I can not see this happening anytime soon. I know there are a "FEW" people that would buy them but those a way to small of volumes to even attempt it as the unit price would be even higher, MUCH higher which means no one would buy them.

[lligetfa]

Chris,
What about having non-hotswap dual power supplies where the second PS accepts a DC input? That way one could buy an AC version, a DC version, or a dual AC and DC version.

[sirhc]

Once again the power supply has to be designed to be able to work in parallel (most are not) and it is a costly option as there has to be something in there to prevent power from one source going into the other in the event one unit is damaged. And whatever you do has to be at least CE but this is a very potential fire hazard depending on what fails.

One power source is connected to another that is in some sort of unknown failure. Seriously there is more to this than you think especially when you consider all the things that could go wrong.

[LRL]

Indeed there is. We've modified quite a bit of hardware from several venders to give us redundant power supplies. But we install diodes, fuses and a few other tricks to deal with internal supply shorts. I won't call our methods the best but that's how we get redundancy in our critical areas without paying the big bucks.

If redundancy is import to you you can go this route and take all the risk on yourself but don't expect warranty it if it breaks.

[Brough]

Let me suggest the minimalist dual power support that MikroTik provides in a number of their products, for example their Cloud Core Routers. The base circuit board includes two DC connection points with series diodes. In some products the two inputs are from a MT-supplied AC to 24vDC power supply or from PoE. In other products (the CCR) it from the supplied AC to DC power supply or via a DC header. In either case, external diodes and other components are not required and we get to deal with what we see as a significant issue, i.e. UPS failure. :)

[sirhc]

I promise to offer spare power supplies on the web store by the end of the month!

Eventually we will also sell FANS and replacement boards that get hit by lightening.

We may also offer board repair service/exchange once we get things moving.