UPS For Server Cupboard

[Butuz]

I would reccomend you go with multiple smaller UPS's rather than one bigger one. I use 3 x SMARTUPS3000 2U with each server wired into alternate UPS's so that if one UPS fails it won't take any servers out. This seems a nice way of doing it and actually one UPS did fail just after its 3rd birthday and everything kept on running because the other 2 ups's took the load up. (this only works if your servers have two power supplies, whch most have nowadays).

 

Another reason is that small UPS's can each use a standard 13 amp socket, wheras one big monster UPS will require a 32amp dedicated ring main installed £££

 

I wouldn't reccomend creating your own UPS - it can be done and is not difficult but multiple 12v batteries wired in series AND paralel are extremely dangerous I wouldnt fancy having to go to court because a homemade battery shorted / exploded and burned the school down! Frankly I'd rather APC take the risk on that one for me!

 

Butuz

[dhicks]

I use 3 x SMARTUPS3000 2U with each server wired into alternate UPS's so that if one UPS fails it won't take any servers out.

 

That's a good idea, thanks. I doubt we'll be buying servers with redundant power supplies, though - we handle redundancy by having function mirrored between the two server cupboards, which gives us a good solution to handle a complete diasaster (fire, flood, etc) too.

 

Another reason is that small UPS's can each use a standard 13 amp socket

 

Good point. I think I'm going to be asking for half-a-dozen 2200VA UPS' - one for every couple of servers.

 

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David Hicks

[SYNACK]

How much heat do they put out? How heavy are they - we don't have a proper rack in the cupboard, just a coffee table, which I don't think is going to be up to holding a UPS. Could they stand under the table on the floor?

 

They don't put out too much heat, they are heavy little buggers though, a 2200VA rackmount is about 40KG, tower is about the same.

[dhicks]

They don't put out too much heat, they are heavy little buggers though, a 2200VA rackmount is about 40KG, tower is about the same.

 

Many thanks. Do I assume a 3000VA UPS is around a third heavier, then? I have to get these up a narrow staircase to an upstairs cupboard, so the 2200VAs are looking like the best option...

 

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David Hicks

[SYNACK]

Many thanks. Do I assume a 3000VA UPS is around a third heavier, then? I have to get these up a narrow staircase to an upstairs cupboard, so the 2200VAs are looking like the best option...

 

Yeap they get heavy quickly, I managed to rupture several discs in my back with the 2200VA one we have here when I installed it down low in the rack by myself without thinking. You should have two people at least to do it as they are also an awkward unbalanced weight with heavy batteries at the front and not so heavy chunks of copper (transformers) at the back. We put in a 5000VA later and I directed from a distance.

 

Going with the 2200VA ones is probably a good idea but does limit your reserves if your loads are unevenly distributed, having it all in one bigger unit means that you can have all devices share the output and shutdown in order of importance to give the best runtime. The larger units also often come with the management cards included which can make it cheaper and means you only need one management card. For max reliability it is best to have two UPSs that can each cover the full load connected to separate power feeds and each server connecting via dual PSUs to each. Most budgets including mine don't stretch that far though. We have 4 servers off a 2200VA APC 2xML380 G5, 1x ML350 and 1x ML110 which gives about 12 minutes runtime at 50% utilization, we have dual PSUs and the old unrelaible HP UPS hooked up to them so this shared the load out to about 30% utilization. Either UPS will carry the load but the HP one falls over if the wind blows the wrong way so it is up to the APC to all intensive purposes.

 

I think that there are some cases and or adapters that do allow for two standard PSUs to be connected in tandem to provide dual PSUs at a much cheaper price point. They appear to be difficult to find though from 5 minutes on Google anyway.

[pete]

Sissies. No sense of adventure.

 

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David Hicks

 

After reading about the Ikea racks, I was seriously tempted to see what fiendish Heath Robinson contraption I could encourage you to build for backup power.

[dhicks]

The larger units also often come with the management cards included which can make it cheaper

 

I'm going to be sticking with my very cheap spare-PC-that-shuts-down-if-the-power-goes-off system, and we only need 10 minutes or so runtime to allow for everything to shut down.

 

I think that there are some cases and or adapters that do allow for two standard PSUs to be connected in tandem

 

Or two IEC power cords, some wire strippers, heat shrink and a blowtorch...

 

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David Hicks

[dhicks]

I was seriously tempted to see what fiendish Heath Robinson contraption I could encourage you to build for backup power.

 

I was reading something on Slashdot today about potato-powered batteries...

 

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David Hicks

[SYNACK]

Or two IEC power cords, some wire strippers, heat shrink and a blowtorch...

 

Here we go IEI, the industrial computer provider focus on industrial boards, display, embedded system. - ACE-R4140AP, way expensive but i had to prove they existed. Turns out that you can't really get two standard ATX PSUs to team up (redundancy) as they tend to melt everything as they need to be designed in a different way to be able to team.

 

The Y cable would may work to cut the UPS out of the single point of failure loop but that still leaves the single PSU . BTW I would not recommend the Y cable as the UPS conditions the voltage level and waveform (depending on quality of the gear) and I don't know what would happen in a UPS deathmatch to be in control .

 

You could probably use a Microcontroller to moniter and shutdown everything if you wanted, would use very little power and be very robust. I think that the beagleboard even runs quite a range of linuxes and hardware.

[Butuz]

DO NOT UNDER ANY CURCUMSTANCES MAKE UP A "Y" LEAD to connect two UPS's into one PSU (that is unless you actually like explosions, fire, and possibly death).

 

With regard to weight - take the batteries out before you move the UPS's!!! The 2200 and 3000 rack mounts (weigh nearly the same) are approx 20kg for the battery and 20kg for the chassis so you can install one yourself as long as you seperate the battery. (I think the tower versions are heavier). It is easier with 2 peeps tho!!!

 

Butuz