Recommend better UPS solution

Discussion in 'Power Supplies' started by Red Squirrel, Nov 2, 2017.

  1. Red Squirrel

    Red Squirrel Lifer

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    I mentioned this before but figured I'd make a thread.

    My current UPS is a Tripp Lite inverter-charger, I went that route as I want to use large flooded acid batteries so I can cheaply have good run time. These batteries also last longer if they are cared for better. My current setup gives me about 4 hours, possibly more. Not often we get a power outage that lasts more than a few hours.

    The problem I've run into is that because it's a standby UPS, like most home UPS solutions, there is a delay before the servers see AC power when the power goes out. If it's a clean cut, it's ok, but if it's a very dirty cut, like a wire arcing somewhere or a huge surge or brownout, the servers will see the brunt of that before the UPS kicks on. I've had two incidents so far where I lost servers as the UPS did not trip fast enough.

    My goal is to look into a telecom style setup, basically -48v rectifiers, a battery bank that is kept floating. In telecom all the stuff runs on -48 but since it's going to be hard to find -48v psus for computers I will just go with a -48v inverter and then have everything on AC. If power goes out, even very dirty, the rectifiers will just go off and batteries will continue to handle the load. The beauty with this setup is being able to just add more rectifiers and more inverters to expand. Eventually I would also add solar to the mix so the rectifiers would run a bit below float voltage and the solar charge controller would actually be what charges the batteries. The rectifiers would just be to keep them at a decent capacity over night.

    Problem is, it's very hard to find telecom rectifiers and stuff. Especially the chassis that they sit in. The modules themselves go into a chassis and that's what actually controls the output voltage, equalization etc. I've searched a lot and only real option is Ebay but then I don't know what I'm getting or how reliable it will be. Shipping is also prohibitive on lot of that stuff. For inverters I could probably look at solar stores though, but I rather go with something that's fully rackmount. Solar stuff tends to be made to go on a wall and I don't really have lot of wall space in my server room.

    I'm probably going to stick with the telecom stuff and just keep trying to see if I can get lucky and find a site that sells that kind of stuff in Canada, but other than that, I'd be open for suggestions as well. I am also thinking of just building my own power conversion electronics but I have a lot to learn in electronics before I trust anything I build for such a high critical task. If it fails it could cost a lot of money.

    I'd also be open to suggestions for a cheaper temporary fix. Will a power conditioner or something plugged before the UPS help? I'm even thinking just a relay that will shut power immediately if it detects any anomalies such as too low of a voltage for more than 1/4th of a 60hz cycle. But I imagine that's what the UPS does, it's just that the dirty outages that involve random voltage fluctuations before it goes off don't trigger the circuitry fast enough.
     
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  3. XavierMace

    XavierMace Diamond Member

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  4. Red Squirrel

    Red Squirrel Lifer

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    I don't want to pay that much money for something that's not really expandable. Shipping alone on that thing is like $170. That unit may also be standby (like most standard UPSes) so it would not solve the issue. Listing does not specify. If I wanted to buy a standard UPS I'd just get one locally or at a retailer that will have a cheaper shipping rate.

    I want to stick with something designed to work with flooded cells as they are the best bang for the buck in terms of capacity.

    Though as a temp fix I do wonder if I find a dual conversion UPS if I just put it after my own UPS. Just not sure how well it would handle the square wave output. That's another thing, any new solution I go with I want to go pure sine.
     
    #3 Red Squirrel, Nov 2, 2017
    Last edited: Nov 2, 2017
  5. XavierMace

    XavierMace Diamond Member

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    It's line interactive which covers brownouts and how expandable do you need? With ERM's you can get 6 hours of run time with 600w load. How much equipment are you trying to run in a power outage?
     
  6. Red Squirrel

    Red Squirrel Lifer

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    For now I'm only running about 400w, but my goal is to eventually go solar, so I would expand the system to maybe 2-4kw and it would run all the important loads around the house and have solar power "injected" in. That's why I am thinking rectifiers + inverters since I can just hook anything I want to the DC buss. Wet cells are are also cheaper and last longer than gel cells.

    Though since I have two PDUs as a temp fix suppose I could get one of those rackmounts as the redundant PSU of servers would take over from that UPS if the main one takes too long to switch to battery.

    I was looking at DC solutions by Alpha and they have what I want but no way to actually buy it. Probably have to be a company with an actual purchase department to buy from lot of those places.
     
  7. XavierMace

    XavierMace Diamond Member

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    At that point, you'd probably be better off posting this in Home and Garden rather than Power Supplies since it's not longer a computer related question.

    It's your house/money, but personally for the servers, I'll stick with my 4 hours run time in 4U of space. My entire setup fits in a 12U rack.
     
  8. Red Squirrel

    Red Squirrel Lifer

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    How much did each of those expansion bays cost though, and how long do the batteries last before they need replacement? That is one of my main reasons for going with flooded cells as they tend to cost less per amp hour and last longer. 10's of years if you take good care of them, though I did buy cheaper batteries so I imagine after 10 years I'll want to consider replacing them. I'll need a new battery bank when I go 48v anyway since not all of the batteries in this bank are from the same batch.

    I was just hoping for maybe a solution I have not thought of already, but maybe as a temp fix I'm just going to try to find a line interactive or dual conversion UPS and then stick it on the second PDU. The server that is the most affected by these brownouts happens to have redundant PSUs.

    For more solid solution I'm either going to keep trying to find a source for telecom rectifiers/inverters or play around myself with power conversion to see if I can build anything I can trust in a 24/7 operation. I may also buy a single module from Ebay (the modules themselves arn't that hard to find, it's the backplane chassis) and experiment to see what kind of interfacing I can do with it outside of it's designated chassis. Maybe I can manage to run a few without the chassis. The modules are not that hard to find, it's the chassis.

    I'm surprised 48v computer PSUs arn't more common, but if they were I could skip the inverter and power directly from 48v. One less conversion stage.
     
  9. XavierMace

    XavierMace Diamond Member

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    I paid $200 for the UPS and ERM. 3 to 5 years is the normal lifespan for the batteries.

    I'm not sure why you'd expect 48v PSU's to be more common.
     
  10. Red Squirrel

    Red Squirrel Lifer

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    That sounds like one hell of a deal you managed to score at the time. When I search they want more than that just for the shipping an empty unit. I had looked into it originally as some of those APCs will run off flooded cells, but I had chosen to just get an inverter-charger which is designed for it. My goal was always to go with a 48v system in the future but this was a cheaper solution for now.
     
  11. XavierMace

    XavierMace Diamond Member

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    Don't live in Canada then? LOL. I've had multiple APC units, never paid more than $200 for them, never had one smaller than 1500va.
     
  12. JoeBleed

    JoeBleed Golden Member

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    what kind of gear are you looking to run? computers only or other appliances?