Frequent outages and sharp voltage swings are the biggest threat to any piece of electronics in a home, an office or a shop. The trouble is that the word UPS is used for devices that work in completely different ways and sit at very different price points, so buyers get stuck between two main types: Line Interactive and Online Double Conversion. This guide explains the technical difference in plain language, shows when each type is genuinely the right call, and how to size the unit you actually need instead of overpaying or buying something smaller than your load.
The core difference between the two types
In a Line Interactive UPS, mains power passes straight through to your equipment as long as it stays within an acceptable range, while a built-in AVR steps low voltage up or high voltage down without draining the battery. On a full outage the load transfers to battery within a very short window measured in milliseconds, fast enough that a computer or a router never notices.
An Online UPS works on double conversion: it turns the incoming AC into DC, then rebuilds it from scratch as clean AC. Connected equipment therefore never touches raw mains power, and there is no transfer time during an outage because the inverter always runs. That buys complete isolation from grid problems, at the cost of a higher price, slightly higher energy use and usually an audible cooling fan.
What to check before you buy
- Size the load in watts, not VA alone: the VA figure is not the wattage. Real capacity equals VA multiplied by the power factor the manufacturer states, and that factor is below one. Add up your equipment in watts first, then choose.
- Leave headroom: do not load the unit past seventy to eighty percent of its rating. Headroom extends battery life and prevents sudden shutdowns.
- Decide how much runtime you need: backup time depends on battery amp-hours and battery count relative to the load, not on the VA figure alone.
- Match the type of load: computers, monitors, networking gear and CCTV run fine on line interactive, while servers, NAS boxes and sensitive equipment deserve online.
- LCD screen and data port: a display shows voltage, load percentage and battery state instead of leaving you guessing, and a port allows automatic safe shutdown of the computer.
- Battery replaceability: the battery is a consumable that dies before the unit does, so pick a model with standard cells that are available locally.
Mini UPS GeTX GSP2 to keep the internet alive
A compact 36W unit built for loads that run on DC directly, with 9V and 12V outputs plus 15V, 24V and a PoE port. Its value is keeping the modem, the router and a small camera running through an outage without buying a large UPS.
UPS GeTX GXK-1000-C for light home use
A line interactive 1000VA unit with an LCD screen and two 12V 7Ah batteries. It suits a single desktop with a monitor and a router, or a small CCTV setup. The display makes it easy to watch the load percentage so it never crosses the safe limit.
UPS GeTX GXK-2000-C for a multi-device office
A 2000VA unit with two 12V 9Ah batteries, suited to a strong workstation or several light devices in a small office. It stays in the line interactive class, meaning AVR correction for voltage swings and battery reserved for a full outage.
UPS Gaming GeTX GTXF-3000 for heavier loads
The largest line interactive unit here at 3000VA, built around four 12V batteries instead of two, a configuration that gives longer runtime and wider headroom. It serves a gaming PC, a video editing station, or a corner with several devices that must not shut down.
UPS GeTX Online GXK-1-1-1-CO as the entry to online
The shortest route to genuine double conversion at 1000VA, with an LCD screen and two 12V 9Ah batteries. It fits a small server, a NAS box or a point-of-sale system that tolerates no momentary interruption, and areas where voltage is permanently unstable.
UPS GeTX Online GXT-2000-CON with a high-frequency design
A 2000VA high-frequency online unit with an LCD screen and six 12V 7Ah batteries. The larger battery count gives longer runtime, which makes it a logical pick for a small network room holding a switch, a server and a camera recorder.
UPS APC Easy Online SRV 3000VA for critical environments
A 3000VA online unit running on 230V from APC, one of the most widely deployed brands in professional environments, with well-known batteries and spares. It is usually chosen for a network cabinet, a company server or a lab, where downtime costs far more than the price gap.
Common mistakes when buying and using a UPS
- Confusing VA with watts: buying on the VA number alone usually lands you with less capacity than you need.
- Loading it to the edge: running near maximum capacity shortens battery life and makes sudden shutdowns likely.
- Connecting the wrong loads: laser printers, air conditioners, fridges and pumps are heavy thermal or motor loads and do not belong on a battery output.
- Chaining it to a cheap power strip or another UPS: a UPS goes into a wall socket directly and is never fed from another UPS.
- Ignoring heat: placing the unit in a closed cabinet or near a heat source cuts battery life sharply.
- Never testing backup: cut the power on purpose from time to time and watch how long the unit holds, because a dead battery gives no warning.
Frequently asked questions
What difference will I actually notice between line interactive and online?
Line interactive moves the load to battery a very short moment after an outage, which most home and office devices never sense. Online has no transfer time at all and delivers fully rebuilt power, so it is used with sensitive equipment or where the grid is very poor.
What UPS capacity do I need for a desktop and a monitor?
Start by estimating consumption in watts; a typical desktop with a monitor usually lands between 150 and 300 watts depending on the graphics card. Then pick a unit whose wattage exceeds that by at least twenty percent, and rely on the watt figure on the spec label rather than the VA number alone.
How long does a UPS run after the power goes out?
There is no fixed answer, because it depends on the load relative to battery capacity. The practical rule is that ordinary UPS units are designed to give you minutes, enough to save your work and shut down safely, not to run a house for hours. Anyone who wants hours needs a larger power system, not a UPS.
When do I need to replace the UPS battery?
The sealed lead-acid batteries used in these units typically last three to five years, and that shortens with high heat and repeated deep discharge. The clearest sign is a noticeable drop in backup time, or a replace-battery warning on the display.
Does a UPS replace a voltage stabiliser?
Line interactive units include a built-in AVR that handles swings within a set range without draining the battery, and online units rebuild the waveform entirely. So the unit covers stabilisation for whatever is plugged into it, but it protects nothing else in the house.
Practical summary
If your goal is protecting a computer, a camera system or ordinary devices from outages and voltage swings, line interactive does the job efficiently and for less, and you size it by watts with headroom. If you own equipment that tolerates no momentary interruption, or you live where the grid is very poor, online is the right investment. Every unit mentioned here is available with delivery to all Iraqi provinces and cash on delivery, so you can inspect it the hour it arrives before you pay.
