UPS & Invertor

WikiAnswers - WHAT IS THE Difference between an inverter and UPS

I didn't mention the battery charger in the UPS and also that the smaller units have the battery (batteries) included in the same box, and also that there are a lot of different signals, leds and sounds available to bring to your attention that - charging is going on - power is ON or OFF. Thanks for the help. a GA too.

They are available in different ratings from 250VA to 10KVA as sine wave or square wave with different efficiencies.

Invertors will change DC to AC with step up or step down voltage level. It requires external DC source of required VA and AH ratings (for the required number of hours of use)

An UPS is an un interepted power supply. Means it should supply power conituously to the equipment load, which are sensitive to power failure even for a fraction of a second like PCs process controllers etc.

Normally an UPS containes an inverter which will be operated by DC converted from power line in parellel with a battery pack, which will be normally on float charge. When the main supply failes the UPS will operate from the back up battery bank. Hence the load will not miss the supply even for a fraction of a second, as the same inverter is continuing the supply to the load.

With the current interest in alternate energy in the world dozens of companies have appeared building a large variety of inverters. As a matter of fact it is getting rather hard to decide which one to buy.

If You have a battery charger connected to say a 120VAC line it will convert the AC (alternating current) into DC (direct current) which can be stored in a battery. If you then connect an inverter to the battery you can again produce 120VAC. These 3 components are the basic building blocks of a UPS. In the past this kind of UPS was called "full on line" because all the AC input was converted to DC and all the DC was reconverted to AC. Your load would never see the street power, just the pure inverter power. If the street power failed the inverter just keeps right on running without any interruption (called zero transfer time because there is no transfer).

The problem with this full on line design was that the AC to DC rectifier had to be huge. This was needed so as to provide the load as well as keep the batteries charged.

I installed many SOLA ferroresonant UPS's in the past. A 15KW UPS had a 30KW rectifier portion. They weighed tons. They were indestructable as well.

Now most UPS's are designed around a "line interactive" platform. These UPS's have a very small battery charger which keeps the batteries full when AC is entering the unit. The also have a large line conditioner which cleans up the AC power making it as close to perfect as possible for the load. The inverter section in these UPS's is on but not carrying any load. If the power should fail then the inverters output just increases to handle the load running on the batteries until a generator is started.

UPS's like this generally only have a short run time because they mostly work with a generator back up. The tiny UPS's often found under your desk work similarily but most have a "transfer time" and many produce very poor waveforms.

Where I live we have hundreds of power failures every year. Some clients who share a building with others have suffered from generator problems and come to me for a solution. I design a UPS system using individual components and a huge battery bank. One such design uses 5 IOTA AC to DC converters producing 24Volts at 200Amps maximum. These converters are connected to a battery bank made of 12V batteries configured for 24Volts at 800AH. Next a 5KW EXELTECH MX inverter is connected to the battery bank. This is a pure sine wave inverter and runs 100% of the time. When the power fails the customers computers, which are connected to the inverter, feel nothing and the battery bank can carry the load for 8 or 9 hours. So this component built UPS satisfies thier needs.

In solar systems a new kind of inverter is being used which does not use batteries. They are called "grid-tie" and are designed to run directly with a high voltage DC current from solar panels. Voltages can be around 500VDC. This saves on copper wire because you can cable down from the roof in smaller wires. The inverter then converts this DC into AC and synchronizes it with the grid power. If you are producing more power than you need then you can sell the excess back to the grid(where permitted).

The problem for me where I live with all the black outs is that the grid tie inverter must shut down instantly when the grid does. This is required because if power was fed out to the dead grid you might electrocute personel doing repairs. Also the dead grid would almost certainly overload your inverter.

To resolve this problem you must build a mini-grid using another inverter with a battery back up and sometimes with a generator. The grid power passes through this inverter first then the output is connected to the load at the same place as the grid tie inverter is tied to. When the grid fails the mini-grid keeps running from the batteries of the first inverter. This fools the grid tie inverter into thinking that the grid is still present and avoids having it crash. The primary inverter will run down it's batteries to a predetermined point and start a generator. If you have excess power the grid tie inverter can back feed the primary inverter charging the batteries. This is what we do here in this country to offset black out inconveniences.

I hope this has been useful information

As it has already been stated by previous contributors....

Simply put: A UPS does Ac to DC Then DC to AC (as converter - Inverter) Then makes sure that the AC supply to the equipment is not interrupted long anough to disrupt the equipment function.

There are different types but all with the same end result and slight performance difference which requires you to select according to the need.

their are type of inverters they are:- a) ON-Line inverter b) OFF-Line invertor *ON-Line inverter has further discription as UPS means uninterrupted power supply these r also the type of inverters. these kind of inverters don't let the tube-light to blink it supplies the power within 2-3 seconds which dont let the device to switch off while working the best example for UPS Inverter is the computer if we r working on it then if the light goes off then ur PC is switched off. or using other inverter *OFF-Line invertor has further discription as 1)Sine Wave Invertors provide the sine wave as ac Power supplies from the main line 2)Square wave Invertors provide the square wave provides the battery square wave the difference between both is that sine wave is better than square wave becoz the home appliances work on the ac power supply and it provies ac supply as a backup and square wave provides the noise in the home appliances when they r power on .it doesn't provide the pure power supply to the home appliances.

By the way, some home ups don't function well with Mod. sine wave inverters.

Transfer problems between the two.

Two very good GA's early on!

[s]their are type of inverters they are:- a) ON-Line inverter b) OFF-Line invertor *ON-Line inverter has further discription as UPS means uninterrupted power supply these r also the type of inverters. these kind of inverters don't let the tube-light to blink it supplies the power within 2-3 seconds which dont let the device to switch off while working the best example for UPS Inverter is the computer if we r working on it then if the light goes off then ur PC is switched off. or using other inverter *OFF-Line invertor has further discription as 1)Sine Wave Invertors provide the sine wave as ac Power supplies from the main line 2)Square wave Invertors provide the square wave provides the battery square wave the difference between both is that sine wave is better than square wave becoz the home appliances work on the ac power supply and it provies ac supply as a backup and square wave provides the noise in the home appliances when they r power on .it doesn't provide the pure power supply to the home appliances[s]