Prior to selecting the UPS, it is necessary to determine the need. UPS may be needed for a variety of purposes such as lighting, startup power, transportation, mechanical utility systems, heating, refrigeration, production, fire protection, space conditioning, data processing, communication, life support, or signal circuits.
Some facilities need an UPS for more than one purpose. It is important to determine the acceptable delay between loss of primary power and availability of UPS power, the length i 140 rfe reasons 2017 time that emergency or backup power is required, and the criticality of the load that the UPS must bear.
Single Phase power is used in most homes and small businesses and adequate for running lights, fans, 1 or 2 ACs, some computers and motors up to about 5 horsepower; a single phase motor draws significantly more current than the equivalent 3-Phase motor, making 3-Phase power a more efficient choice for industrial applications. While it is expensive to convert to three phase from an existing single Phase installation, 3-Phase allows for smaller, safer and less expensive wiring.
Most consumers of electricity in India have a three phase mains connection if the total load is more than KW. Only if expected load is below KW, then the consumer gets a single Phase connection. Even when the consumer has a three phase connection, the choice of three phase or single phase UPS depends on several factors like the loads to be connected to UPS and also electrical distribution within the facility from the building incomer, electrical switchgear and distribution units to the room the loads to be protected are within.
This not only builds up a complete picture of the electrical circuits on-site. It also helps to determine whether to offer a three phase or single pPase UPS system. In UPS there are three potential phase configurations available. This is because a 3 phase mains or generator supply actually consists of three single phase supplies and a neutral with a degree phase orientation between the them.
A 3 phase supply can deliver more electrical power than a single phase supply. The laws of physics and Ohms Law also come into play, meaning that cable sizes also increase in diameter as amperages rise.
This is due to the output amperage and cable requirements. Most datacentres, commercial and industrial buildings will have a 3 phase electrical incomer that connects them via a local distribution transformer to the Mains. Three phase circuits may be required throughout the building to carry the large amounts of electrical power required for large KVA three phase This is a generalisation as many environments can include both single and three phase loads of course.
Using a three phase UPS system can simplify a power continuity plan and allows a site to adopt a centralised power protection plan, where one large UPS is used to protect a complete building or critical circuits and operations within it. This is in contrast to a decentralised power continuity plan using a number of smaller UPS dispersed to protect clusters of loads like computers and lower power equipment The wall sockets that we typically plug into are single phase supplies rated at Vac 50Hz in India.
Typical examples would include ATMs, small lab equipments, desktop computers, file servers, switches, routers, hubs and telecoms systems. When sizing UPS it is important to know the phase configuration required by both the mains supply and the loads, in addition to the overall load size.
Electrical consultants and electrical contractors will often state both load size and phase configuration.Do you need a 12 volt battery for your application but don't know what size? This calculator is designed to help you find a deep cycle battery when a continuous load is applied, not for cranking or starting purposes. If you know how much power your application takes to run, and the time you would like to run it, we'll recommend a 12 volt battery with a safe amount of AH Amp Hours that will give you the runtime you need.
Choose Your Battery. Full Name Should contain only letters, numbers, and '. Email Address - will not be published Email address should be formatted user domain.Battery selection
Subscribe to comments with RSS. Ray Haws I have a watt inverter I have a 5amp load votts. That calculator will tell you how many amps you are pulling out of the battery. Then you can use the calculator on this page… I went ahead an found out using the Inverter Calculator that you are pulling That is a high draw if you plan on running off a battery for any length of time.
Alex I have a small 12 volt, 2. I need to know what type of 12 volt battery to run it for up to 8 hrs at a time. From what I have learnt by reading all of the post that means I have ah and a 12 volt battery bank. I purchased a10ah smart battery charger, it was half the price and I got a bit excited, my question is will this fully charge these batteries eventually? Also not keen on burning the car down. Lastly, trying to fit a square peg in a round hole, what if I was to get a manual battery isolator to split the batteries back to ah then just switch the alligator clips between batteries, a bit of stuffing around but wil his charge the batteries fully?
I would like to go camping every month but the reality is times a year for only weekends away and 1 week somewhere special. But I would still like it set up to work as it should. I run a small fridge led lights all around and basic charging necessities iPad etc. Sure the charger will charge the battery bank eventually, but I would consider it mostly a maintainer due to the size of the battery pack. By trying to use two on one battery they might interfere with each other, and one might just go to float mode if it sees the battery is at a higher voltage from the charge coming off the other charge controller.
As far as moving the charger from battery to battery I simply suggest charging them as a pack, as that is how they are tied together. Thank you. BatteryStuff Tech Emeka, If the fan runs off 12v then you can connect it directly to the 12v battery pack.Your Power Solutions Partner.
Alpha Technologies is bringing intelligence to Critical Facilities through Alpha IQ, a CAN-based ecosystem that uses a single IP connection and intelligent peripheral devices to connect to all the power equipment in the office.
If you have an indoor powering application requiring UPS back-up power, simply input your powering requirements into this tool and you will instantly receive a selection of Alpha UPS solutions that meet your criteria. Disclaimer: UPS back-up time information is based on estimation. Actual runtime may vary depending on the operating environment of the UPS, the power factors of the protected equipment and the condition of the UPS batteries. UPS sizing information is provided for reference only.
By continuing to use this site, you consent to receive all cookies on our website. To learn more, please read our Privacy Statement. I accept. Watts Amps A numeric number that is greater than 0 and less than is required. Input Voltage. Output Voltage.To browse Academia. Skip to main content.
Log In Sign Up. Matern Tarimo. This purely depends up on the load. To calculate UPS backup, we have a simple formula. Volts here representing the battery voltage and load in watts.
If powerfactor is unknown, use 0. That would depend on the rating of batteries used for backup. I assume you meant 20kVA there. If you were using V Ah batteries, you would need around 6 of them for around 6 hours backup! But, I presume that would provide more than 6 hours runtime. If the UPS is loaded at its full capacity, it would last 6 hours with those batteries theoretically.
But normally the load would be less than the maximum, and hence more run time can be obtained with the same batteries. If the batteries are rated 12V Ah, for six hours backup at full load, that is VA, you'll need 67 of them. But, six V batteries are required for 6 hours backup. Thus, Assume p. Arrange the terms as required to find the unknown quantity. The typical table is for 12 V batteries six cells of 2 V each.
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By Oki Faith. By Anisur Rahman. Download file. Remember me on this computer. Enter the email address you signed up with and we'll email you a reset link. Need an account? Click here to sign up.Various techniques exist to enable the correct selection of batteries for UPS applications.
The procedure described below is one of the more common. It is also possible to use the IEEE method see link at the bottom of the page. The UPS battery bus voltage is V. The typical table is for 12 V batteries six cells of 2 V each.
However, various options are available, for example if we decided to use three banks in parallel:. Manufacturers provide sizing information for their batteries. Generally this information assumes a room temperature of 25 o C. Batteries which will be operated at different temperatures continuously should be calculated specifically for that temperature.
Calculate Size of Inverter & Battery Bank
Normally information supplied for lead acid batteries designed for short discharge times minutes is in the form of kilowatts per cell tabulated for various back-up times.
The required [Watts] per cell are given by:. Battery voltage varies in use - staring high and then decreasing to it's end of discharge voltage. Taking into account this variation, makes calculation more complicated. If unsure about what the average value to use, then the end of discharge voltage could be used as this is on the safe side.
Steven has over twenty five years experience working on some of the largest construction projects. He has a deep technical understanding of electrical engineering and is keen to share this knowledge. About the author. What is average Disc volt?
Steven, Thanks for the example. One thing I'm not sure is why real power P wattinstead of apparent power S VAis used to size the batteries. As the batteries are d. I think it just makes sense to use Watts for the calculation. Reactive power for the a. It is a device which maintains a continuous supply of electrical power, even in the event of failure of the mains utility supply.
A UPS is installed between the mains supply and the equipment to be protected However, if you prefer you can write, manage This is the first of two posts on the resistance of conductors. In the next post I will look at the ac resistance, including skin effect and we deal with The standard aims to consolidate AC and traction voltages within the industry and defines the following bands: band 1 - A. If you have no idea how electrical circuits work, or what people mean then they talk about volts and amps, hopefully I can shed a bit light.
A fundamental concept behind the operation of alternating current systems is that voltage and current waveforms will be sinusoidal — a Sine Wave. Current transformers CTs are used to convert high level currents to a smaller more reasonable level for use as inputs to protection relays and metering Our IEE cable sizing was wrote a few years ago and had become rough around the edges.
I thought it was time to give the tool a service.Please note that this is an estimation only. For more help please call Power factor is a number between 0 and 1 which represents the fraction of the load current which provides useful energy Watts to the load. Only in an electrical heater or incandescent light bulb is the power factor equal to 1; for all other equipment, some of the load current flows into and then back out of the load without delivering watts.
This current, composed of distortion or reactive currents, is the result of the nature of the electronic load. The important point to understand is this distortion or reactive current, which is forced to exist due to the load, causes the load V-A rating to be larger than the load-watt rating.
The Watt rating system can be thought of as a special case of the V-A measurement system, namely, the case where the power factor is equal to 1. With over 25 years experience in the backup power industry, the directors at PHD Powerhouse have pretty much seen it all.
However, the one thing that consumers consistently fail to understand is battery sizing for backup power systems. Very often consumers will opt for a lower cost quote on a backup system without looking at the finer detail.
UPS Run Time/Battery Backup Time Calculator
In an attempt to win orders, unscrupulous vendors will often skimp on the batteries, making ludicrous claims on runtimes. By offering smaller battery capacities, huge savings can be realised but the runtime claims are often unachievable. There are a number of factors which influence battery selection:. It stands to reason that the bigger the load that one wants to support, the greater the capacity of the batteries should be.
In our example we will use a load of W.
As in point 1 above, the longer the required runtime, the greater the battery capacity will have to be. In our example we will use a required runtime of 1 hour. The battery capacity is therefore limited to the size of the charger. Usually, the battery capacity should be no more than 12x the maximum charge current ie. We will assume that our UPS has a 10A charger. The DC Bus is the voltage required by the inverter to operate and dictates the number of batteries in series required to drive the inverter.
This information is available from the UPS supplier and should be clearly indicated in their spec sheets. DC busses range from 12V 1 x battery to V 40 x batteries. We will assume a DC bus of 36V 3 x batteries.
Inverters use some of the energy supplied by the batteries to run the internal electronics and so not all of the battery capacity is available to run the load. There are many types of batteries available on the market today and since PHD is not a battery specialist, we will not make recommendations here.
However, as a rule we use fully sealed, maintenance-free, deep cycle lead-acid batteries which are common to the industry. For total accuracy it is important to refer to the discharge curves of the particular battery manufacturer however, PHD uses a few rules of thumb to increase runtime accuracies.
For runtimes below 2 hours, a factor of 1. For runtimes above 2 hours, a factor of 1. However, using our rule of thumb for the exponential nature of battery discharge curves, we need to increase the required current by a factor of 1.
However, manufacturers do not manufacture batteries of In this case a 65AH battery. The above calculations may seem a little daunting and many consumers may feel it unnecessary to learn something that they may need once in a lifetime. Ensure that the UPS, batteries, cabinets and installation are each quoted on a separate line with a full description including the number and capacity of batteries.Various techniques exist to enable the correct selection of batteries for UPS applications.
The procedure described below is one of the more common. It is also possible to use the IEEE method see link at the bottom of the page. The UPS battery bus voltage is V.
UPS Battery Sizing
The typical table is for 12 V batteries six cells of 2 V each. However, various options are available, for example if we decided to use three banks in parallel:. Manufacturers provide sizing information for their batteries.
Generally this information assumes a room temperature of 25 o C. Batteries which will be operated at different temperatures continuously should be calculated specifically for that temperature. Normally information supplied for lead acid batteries designed for short discharge times minutes is in the form of kilowatts per cell tabulated for various back-up times.
Calculator | Sizing a 12 Volt Battery to a Load
The required [Watts] per cell are given by:. Battery voltage varies in use - staring high and then decreasing to it's end of discharge voltage. Taking into account this variation, makes calculation more complicated. If unsure about what the average value to use, then the end of discharge voltage could be used as this is on the safe side. Steven has over twenty five years experience working on some of the largest construction projects.
He has a deep technical understanding of electrical engineering and is keen to share this knowledge.
About the author. What is average Disc volt? Steven, Thanks for the example. One thing I'm not sure is why real power P wattinstead of apparent power S VAis used to size the batteries. As the batteries are d. I think it just makes sense to use Watts for the calculation.
Reactive power for the a. It is a device which maintains a continuous supply of electrical power, even in the event of failure of the mains utility supply.
A UPS is installed between the mains supply and the equipment to be protected Electrical engineering is a field that covers a wide variety of sub-fields, including electricity and electronics. It is a field that goes back to the Electrical notes are a collaborative collection of electrical engineering information and educational material.