If one is running a larger UPS like this do you expect it to consume a decent amount of power on its own if there is a light load on it? I dont have first hand experience to be able to say.
3700watt UPS
- Thread starter modder man
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UPS systems usually don't do anything power generation wise other than keep the battery bank trickle charged and healthy until there is a power disruption or a spike detected. Then it switches over immediately to UPS inverted power using the batteries. Nice click of the relays inside the
UPS. You can tell when the UPS is on batteries because they hum quite loudly as well as the alarm and lights going crazy. Mine has a fan that turns on. APC 1500 tower.
Light load isn't an issue except calibration wise, I was reading that APC need a minimum of 30% load to get an accurate reading. Not sure if other brands have a similar mandate. Overload of course is bad.
What brand do you have there?
UPS. You can tell when the UPS is on batteries because they hum quite loudly as well as the alarm and lights going crazy. Mine has a fan that turns on. APC 1500 tower.
Light load isn't an issue except calibration wise, I was reading that APC need a minimum of 30% load to get an accurate reading. Not sure if other brands have a similar mandate. Overload of course is bad.
What brand do you have there?
Looking at some of the larger Dell ones. Have too much hardware to run on one or a few of the smaller ones.
Not all UPS get switched some are on-line doing the conversion already, not all CLICK and not all have very loud annoying sounds, fans and lights.
To answer his question there is loss due to the voltage conversion, there's minor loss to deal with the actual unit system itself ie: that loud annoying fan takes electricity too keep going. While on AC power the unit will consume electricity itself and amount depending on electronics and conversion going on, as well as 'running' the unit itself, very minor.
I just dont want to get a larger ups and then regret it becuase I dont have large loads running all the time.
The larger server UPSs are often online double-conversion units, and they will consume more power than your small "line interactive" units that you can pick up all over. The total efficiency is probably 5% lower but the newer the gear the better the whole process is.
They will convert the incoming line voltage to DC and then convert that DC to the target voltage so that were is always power going to the load from batteries or the input converter without any interruption (the click of relays in smaller units).
A 4kVA UPS isn't too bad, I have 2x 5kVA and 2x 3kVA units @ 240V + 2x 1500VA 120V in the basement. Keep in mind that your normal 15A outlet is only max rated for 1800W and for constant draw you need to de-rate that down to 80% or 1440W. You should run a new line and breaker to power the UPS, and if your equipment will support it run a 240V line and get a UPS that can do 240V to help offset other inefficiencies in the whole system.
If the equipment is only on some of the time, you can also get a few smaller UPS units, use a pair for your always on equipment (assuming dual-fed power) and then another pair for the intermittent equipment and that way get away with a few standard 1500VA units.
They will convert the incoming line voltage to DC and then convert that DC to the target voltage so that were is always power going to the load from batteries or the input converter without any interruption (the click of relays in smaller units).
A 4kVA UPS isn't too bad, I have 2x 5kVA and 2x 3kVA units @ 240V + 2x 1500VA 120V in the basement. Keep in mind that your normal 15A outlet is only max rated for 1800W and for constant draw you need to de-rate that down to 80% or 1440W. You should run a new line and breaker to power the UPS, and if your equipment will support it run a 240V line and get a UPS that can do 240V to help offset other inefficiencies in the whole system.
If the equipment is only on some of the time, you can also get a few smaller UPS units, use a pair for your always on equipment (assuming dual-fed power) and then another pair for the intermittent equipment and that way get away with a few standard 1500VA units.
I do intend to run 240v outlets to the rack. I have no reason not to. the bigger hardware will likely run often enough that there will be no reason for me to run different UPS. This is all at home so there is no need to redundant stuff I just cringe a bit at the thought of no UPS on the big stuff which was the current plan.
I would go for a bigger Eaton or APC unit then, stick to the models that are 1 generation back or < 5 years old just to get better quality tech inside. The newer APC's run the DC insides at ~200V and have easier to work with 2 battery modules with 16x 12V where my previous generation ones are 48V inside and different battery module configuration. Lots of the 3kVA+ units are expandable so you can get chassis that hold additional batteries to increase your run-time if you don't want to shut everything down in < 10 min or so.
If not buying from a place the refurbishes and tests the UPSs, you can buy new batteries online and have them shipped to you as complete modules or individual batteries and just take apart the old pack and put new batteries in them to start out fresh.
If not buying from a place the refurbishes and tests the UPSs, you can buy new batteries online and have them shipped to you as complete modules or individual batteries and just take apart the old pack and put new batteries in them to start out fresh.
I have been looking at the Dell K804N 3750watt UPS. Is this older than what would be preferable to run at home? better to avoid?
Looks like that is a re-branded Eaton unit. No experience with that generation personally but should be fine (the Dell stuff I have used in the past has been re-branded APC units).
Lots of hits on ebay for it so should be easy to get parts/accessories if needed.
Lots of hits on ebay for it so should be easy to get parts/accessories if needed.
That was what drew me to them. Cheap in comparison and many on ebay. This is not production...just over zealous home stuff so all it has to do is work. Though sometimes plex feels like production.
It is a home lab after all....does anyone have any favorite ups in the 3-5k watt range? Pointers? I suppose I am more uneducated than I thought on options and such.
Or we have sufficient income that the cost of our hobbies are not a problem.
Or we dont but we have a problem so we spend the money anyway. At least this is the case for me. I spend so much money on hardware.....I dont need anymore. I enjoy it though so whatever.
Recently I have gotten a few sets of refurbed APC SURT600XLT's for a site I deal with with generator only but no UPS. They have been fine so far, not as splashy as the Dell/Eaton's the OP was looking at but get the job done.
Logged into the mgmt card on one, With a ~30% load (7.8A @ 240V) it reports a run-time of 25min remaining which is about right from past experience loosing power there. No external/add-on battery units just the 2 internal, but it does support them.
The guy I buy them from does just Eaton and APC anymore and reports that they are about equivalent in terms of useful lifetime and ease of repair and maintenance for the 2kVA~10kVA models.
That model APC looks to cost about twice as much as the dell one i was looking at on the grey/used market.
Regardless of the brand, see if you can find a local seller and just pick it up - I bought the 6kVA ones for under $1k each in person with new batteries. 3kVA ones were about $600 as I recall (2-3yrs ago). Shipping adds significantly to the cost, and if they don't also need to come up with a box/crate to ship it in because you are tossing it in the truck then that saves even more.
And cash also works well but that depends on how far you want to go down the "let's make a deal ..." road and who you are dealing with.
And cash also works well but that depends on how far you want to go down the "let's make a deal ..." road and who you are dealing with.