Hey guys, i wanna ask, is it enough to use a 1500va UPS to protect a desktop case i7 6700k and gtx 1070 + a 24 inch 144hz monitor and a Oled LG cx 55 inch tv?or does it need a bigger UPS?
UPS is always enough for everything except sound related devices, like Home Theatre systems or AV receivers/Powerful active speakers in general under serious load.
"Protect"? From what? The purpose of an Uninterruptible Power Supply is to maintain power to a system in the event the primary power source, usually utility power, goes offline, EDIT: or the power quality is reduced below an acceptable level.
Also power fluctuations that can harm components over a period of time. I have lights that dim occasionally that would produce a restart if I didn't have one.
You have to roughly calculate total power draw from the devices plugged into the UPS, your PC under full load is different from your PC browsing the internet, 1500va is roughly 900w, so do some math, your devices should be fine on this UPS from what I can see, but even if all your devices draw 800w at full load you would be looking at 10-15 minutes of backup, so a bigger UPS is always better, but a 1500va will do. A simple way is, what is the size of the PSU in your PC, lets say its 750w, then find the power draw of your TV add them together, are they less then the UPS output, then your fine, the time on UPS power goes up the larger its output.
This^ something to keep in mind is that VA conversion to Wattage is not consistent between UPS vendors because the UPS itself consumes some of it, so while 1500 Va converts to 975 watts, you might get 900 or 938 or 950 watts depending on how much is being used for its own self regulation, any fans, leds etc, so review the products manual (a pdf usually) to see what the units real output is. at 1000-1500 vA, usually you'll get 7.2Ah batteries, usually size compatible with 9Ah, given the minimal price difference between them, i'd go with 9Ah replacements once they are due to be replaced (either 3-4 years or whenever the unit no longer keeps the machine up during a brownout.
power factor is around 0.9 for majority of consumer devices now, especially any with a legitimate bronze or higher rating.
All right, so you are using 0.65 as PF then, could have said that in the first place and mention 975 W is an estimate and not an exact result. This is why I started asking about it. Surely on the safe side though. @ramthegamer Add the nominal wattage of your display and TV to that of your PSU like suggested. If the result is 1000 W or less, I'd say 1500 VA is plenty. The suggestion about using larger Ah batteries is good but only if you need to keep using your system during power outages.
OK so a 550w PSU and lets say at load your pulling the full 550w, your OLED is pulling around 160w, so 710w total, using a 1500va(900w) UPS would be around 5 min, Just the TV at 160w 30min, and just the PC at full load 550w 7min. Use the UPS calculator, https://www.powerinspired.com/ups-runtime-calculator/ I assumed block capacity of 9Ah (output of battery) and 2 blocks (number of batteries). Your PC just browsing and watching videos would be around 120w with the TV also going another 160w for 280w total and 16 min UPS uptime. Once you have the UPS and if it has a digital display it will tell you loads and uptime at said loads.
For what its worth I have a 1500va on just my cable modem/router, UPS says uptime of 180 minutes. UPSs are great, always go for the biggest you can afford, remember UPS have a cost of running, even an idle battery drains so UPS is always keeping them charged.