Hi, I have an APC EPS-350, with two desktops & one laptop, being powered by the UPS, also I replaced the battery on the UPS. This now the 2nd time, it's tripped (High pitched whine), where shutdown PC's > reset UPS > restart PC's, has happened. The rest of the house, shows no evidence, of having a power blip (clocks flashing 12:00 etc) on both occasions, could the three machines, be drawing, current at the upper limits, of the UPS, making it more susceptible, to tripping? I'm planning on adding a 4th machine most likely a server, which would/could further stress, the EPS-350. Any rule of thumb for how many machines on a UPS? Thanks Rico
For me the rule is psu watt ≥ (max load of device 1+ max load of device 2 +....+ max load of device n + 50 watts) Panagiotis
Thanks Guys!!! I have the UPS plugged into a kwh meter & in 24hrs it used/read 14kwh 14kwh X 1000w / 24hrs = 583 w/hr 583/3machines = 194 w/machine I'm anticipating hopefully soon, xenon dual cpu server, plugged into this. currently I should 600w 3 machines + 150w fudge factor = 750 w If an avg desktop takes 200 w, any Ideas, how many Watts for the server might use?
That's easy to tell. Task the connected devices so they are demanding the most power, then pull the UPS plug from the wall and see if it holds. If over-loaded, the UPS will simply shutdown, and so will all your connected devices! But that's obviously not a good idea. There is no rule of thumb! It is just common sense. You make sure your UPS is large enough to support the demands of everything connected to it. Every power supply is (or is supposed to be) labeled with the wattage (or amperes) it consumes. You can add up them all up and make sure the UPS is rated higher. But even that is not really a good plan because computers systems typically draw much LESS power than their users think. The BEST way to calculate the size UPS you need is to measure the power your system is consuming. This can easily be done with a kill-o-watt meter, or you can use the software that comes with your UPS, or if you have a decent UPS with a LCD status display panel, use that. I note this computer right now with an i5-6600, 16GB of DDR4, R7 370 graphics, and 2 SSDs, PLUS my wireless router, cable modem, 4-port Ethernet switch, PLUS "TWO" 24 inch monitors is consuming a mere 127W of power through my UPS! I currently have a dozen web pages open, Word, my email client and Pandora is streaming Billy Idol's White Wedding. The fact I have a 550W PSU is immaterial. It is important to understand a computer (motherboard, RAM, graphics card, drives, fans) will pull from the power supply only what it needs, not what the PSU can deliver. So if your computer demands 150W, it will pull from the PSU 150W even if the PSU is rated at 350W, 650W, or 1000W. And that same PSU will pull from the wall (or UPS) only what it needs to supply that 150W. Assuming an 80% efficient PSU, that would be ~188W (188 x .8 = 150.4W), again regardless if the PSU is a 350W or 1000W PSU. As I noted, today's computers draw much LESS than users think. Another good tool to use to calculate your UPS needs is the eXtreme Power Supply Calculator. Plug in your hardware and the calculator will determine your PSU needs and UPS needs. This is, by far the best PSU calculator out there as it is the most flexible in terms of entries, plus it does not over exaggerate your needs and recommendations. I recommend setting Computer Utilization to 16 hours per day and CPU Utilization to 100%. These steps adjust for capacitor aging and ensure the supply has adequate head room for stress free (and perhaps quieter) operation. These steps also add a little buffer for unplanned future upgrades or added hardware demands. As I implied, all power supply calculators tend to pad their results. They don't want to underestimate your needs. It is always okay to buy too big a PSU (except maybe for the budget) but always bad to buy too small. But the eXtreme PSU calculator is, by far, the most conservative when it comes to padding results, and that is due, in part, because it has the most flexibility.
That "kill-o-watt" meter is fantastic, the kwh purple button, is a toggle btwn. kwh / time so: kwh / time X utility rate* X 760 = monthly cost of what's plugged into the kill-o-watt meter. * my rate $0.0939. The purple button is all, I use, for DC computing project, Folding AT Home ___________________
I have a different UPS question. I purchased the CyberPower UPS I had asked about earlier in the week. The power line-cord is only 5 feet long and that presents a problem for me. The warranty on both the UPS and damage to connected devices is void if there is a surge protector strip OR extension cord beteween the UPS line and the wall socket. I am not all that concerned about the warranty, assuming it is likely to be of little practical value. I do understand the issues involved when conecting the UPS, that has it's own surge protector and AVR, to a surge protector. I do not understand what issues would be caused if I used a simple heavy-duty three-pronged extension cord of the same grade/capacity as the line cord of the UPS. Are there any serious issues in using such an extension cord?
No! Assuming the extension cord is a nice, heavy duty cord AND not damaged in any way, then there are no problems. One word: lawyers! The problem is, they cannot prove you didn't use a faulty extension cord, perhaps one missing the ground wire. A missing ground on any electronic device could present a safety hazard. In the case where they offer a warranty for your connected devices, lawyers interject language for disclaimers - to cover their ***, not yours.
A power meter is hardly the best option to measure the power. And having loaded a dozen web pages, word and ... whatever program hardly stress the system. The UPS should at least be capable of handling the max load of cpu and gpu (easily calculated by the sum of cpu tdp and gpu tdp). In the above example your system/devices would consume (when stressed) cpu 65W+ gpu 110W =170~190W, 2x (35~50)W for the monitors + max 15W for the router + max 15W for the modem + 10W for the switch= 280~330W. If it was immaterial you would have used a 250-350W UPS and not have opted for a 550W. ps.I'm only posting this because a user could use a power meter to measure the power of his devices and then buy a ups based on that, only to find out that he throw away his money. Panagiotis
APC explain here does not talk about the Extension cord. #1. Most likely liability protection, from using, undersized cord #2 A long extension cord, may add more resistance, than the provided cord, changing expected values. Just Guessing In my case I do not think this applies (post #5), as the load is pretty much steady, or max. Distributed computing, set to 'full power/always on', so the kill-o-watt meter, values would be representative or typical. From logging values in excel, 14Kwh daily, is consistent over time. Therefore 3 machines use 582watts, therefore 50watts fudge factor = 732watt UPS. Would have room to spare without overload. Note the 50 watts fudge factor per machine, is IMO overkill for me. As the current 200W UPS, running 3 machines, consuming 582W. Has tripped on over load, twice in ~3 months. It will probably die much sooner, from the continuous overloading. I'll look for 600W UPS for my three machines to use.
Rico I do not understand why have you hooked devices that draw 582watts on a 200W ups. A surge protector would do the same job. The +50Watts factor that I posted earlier is not per machine. And I only mentioned it because some ups that I had in the past could not handle in reality their advertised power output and shut down before the systems that were plugged on them had the chance to gracefully shut off. eg. if you need a 600W ups is better to opt for a 650W one just to be on the safe side. Panagiotis
See post #1 I was seeking knowledge as to why, I've had several trips, of the UPS. In post #1 I thought, I did not have a problem, so sought advice. I thought (now know better), the only 'disadvantage would be, the battery, & that power would pass through, & surge protected, again my assumption, was the battery life. In the APC line: BRG1000, 1300, 1500, W = 600, 780, 865, I chose 780W, as a preferred 650 is not offered. The diff. in price btwn. 600 & 780W is $18.00.
Got it. By the way since you intend to connect multiple systems on it you should make a script to send a shut down command on all the machines when you have a power outage. See here for more info: https://community.spiceworks.com/topic/139191-shutdown-multiple-servers-from-my-ups http://serverfault.com/questions/10...get-them-to-both-shutdown-when-battery-is-low https://technet.microsoft.com/en-us/library/bb491003.aspx Panagiotis
@Panagiotis - I believe ist even simpler than a script. Plug on PC into master (rear of UPS) plug others into Master controlled outlet. Should master fail, the others will be turned off
ist? You mean an outlet that when the master is on, the slaves power on and when the master is off, the slaves cut the power? If you don't care about shudden power cut of the other devices you do not have to use an extra outlet. Most UPS apps have an option to "turn off the ups" after the system that communicates with the ups stuts down. The script is needed if you want to gracefully shut down all the connected systems before shutting down the ups. Panagiotis
That would shut down the other two machines, but like you say not gracefully. I posted before thinking, trip the UPS, which activates the 'script' which sends 'shutdown.exe', is Grace action. Thank You
You are welcome. as a not if you want to use a script or a program to shut down the machines you must ensure that their net connection is active = either plug them on a switch power by the ups or protect also your router with a small ups. Panagiotis
Hi, Newbie UPS user here. After a storm killed my laptop on Christmas Eve (flooded roof) I replaced it with a desktop PC and have been wanting to buy a UPS ever since. Well, I've had the power go off here for couple of hours the other day and again today which has sort of forced my hand to buy a UPS. This is the one I've bought - the 1200KVA / 720 Watt model. https://powershield.com.au/powersheild_product/defender/ https://powershield.com.au/wp-content/uploads/manuals/PowerShieldDefenderUserManual_20170123.pdf Anyway, It says to allow 6 hours to charge the battery, even though the display shows it is charged. I'm sure this is a silly question, but do you need to shut the UPS down to charge the battery? Or will it charge while on and powering my devices? Also, how often would one expect to have to change the battery? Do you really need to install their software? All advice welcome. Thanks, Krusty
It will charge when you have devices on. It should just pass through the mains. Five years for my Belkin but the software tells you battery state. No windows has its own software you can use. There is free software also but I forgot the name.
