All battery sizing calculations in this paper have assumed a standard room temperature of 77 25c. The vrla ups series battery part numbers also reflect the batterys approximate capability. More often, an average voltage value is taken and calculations based on. Step 1 select and size the battery step 2 calculate discharging current step 3 select conductor size step 4 calculate short circuit current step 5 select protection devices. Voltage regulators surge protection devices hardwire surge suppression audiovideo solutions. Select the battery model number and quantity using the typical watts per cell table for a 300 kva ups, 94% efficiency, power factor of 0. Use the correct battery rating 100hr, or a battery rating that approximates the actual autonomy hours for the system load. Calculate ups rating in kva based on load, power factor, assumptive ups efficiency and specified design margins. Apc ups selectorcalculator find the correct battery backup. Aug 24, 2009 in my experience, if your ups is located close to your battery, there shouldnt be any problem as your battery is solely powering the ups and how much input power taken from the battery does not necessarily depend on how long your ups output power travels.
Looking at the capacity, we see that the required wattcell is too much for one bank. In this calculation, it is assumed that the ac ups is a double conversion type with a basic system topology as shown in figure 1. A ups series battery may be rated as capable of providing 475 watts per cell for 15 minutes to 1. Ups load that need to be supported input output ac voltage autonomy time battery type 5. The solution you require is more complex than what we can easily recommend with a few questions. With a few simple questions and calculations, you can identify your power needs and find the right eaton ups.
Sizing battery banks for switchgear and control applications is commonly performed using software designed specifically for that purpose. The inverter of ups provides a constant voltage to the loads connected to it. Maximum system voltage minimum system voltage correction factors e. In some cases, the manufacturer will independently size the system and it is only necessary to construct the ac ups load schedule and load profile. Design and specification for safe and reliable battery systems for large ups revision 0 by pearl hu white paper 207 a properly designed ups battery solution is important for safe and reliable operation. Calculator ah typical power consumptions bullet m5 remember. Usually, the battery capacity should be no more than 12x the maximum charge current ie. Design and specification for safe and reliable battery.
Battery sizing is crucial in order to ascertain that it can supply power to the connected loads for the time period it is designed. F, burying the battery can bring it back to near normal life expectancy. Battery sizing the battery capacity for a pv system can be calculated using the following formula. An array of battery designs and extensive technologies are available to the user.
Ieee std 485 battery sizing procedure shorterduration, highercurrent applications max current greater than 20hr rate max current much greater than average current common applications. Capacity testing of vrla batteries 20 to 200 amperehours. Purpose of uninterruptible power supply ups the purpose of this publication is to provide guidance for facilities engineers in selecting, installing, and maintaining an uninterruptible power supply ups system after the decision has been made to install it. The ac ups sizing calculation determines the ratings for the main ac ups system components. Sizing margins or making batteries bigger if the calculation requires a 220 ah battery, and the next cell size up is 250 ah the 30 ah difference is a % margin, designed in an additional margin of 10% might not be required. We are going to focus on choosing the right battery size for your ups. Nov 04, 2014 the ups sizing calculation can be done when the following prerequisite information is known. Here are several options and tools available to assist in sizing the right ups. Short circuit current rating for an individual cell or multicell unit can be available from the battery mfr.
Uninterruptible power supply ups computer and peripheral network and server data center and facility 3 phase ups special applications ups management ups replacement batteries surge protection and power conditioning. Taking into account this variation, makes calculation more complicated. Basic battery sizing approach determine the load profileover the autonomy period size a battery bank to have sufficient capacity to provide the required energy over the autonomy period, accounting for. The vrla battery is rated in amperehours or watts per cell wc at specific discharge time durations. For example, a tel series battery may be rated as a 100 ah battery capable of providing 12. Just input the required load profile, and the program selects the optimum battery configuration. Select the right ups for your home, home office, small business, server room and network closet, or data center facility. For example the ups 12350mr is a 12 vdc battery of 6 cells which is capable of delivering 348. We are here to help and our experts can provide you with the right ups choices. Total vah 18 x 12 x 28 6048 vah the following assumptions have been made in the above calculations. Using either of current, active power, apparent power or reactive power as inputs other parameters can be obtained for a three phase system where line to line voltagevll and power factor are known.
May 31, 2017 following our previous guide on calculating the right ups capacity for you, today we move on to the next part in the series. For convenience in sizing, the batteries are rated in watts per cell for a. F can be brought up to 85% to 90% capacity by burying it. The capacity of such a battery is the sum of the capacities of the strings. The battery manufacturer shall be consulted regarding the sizing of the battery shortcircuit protections and for battery shortcircuit current values. System voltage temperature aging maximum depth of discharge rate of discharge.
The standard recommends a duty cycle be drawn showing the anticipated loads in ampere or power for the required duration of battery backup time. The formula employed rating calculation is as stipulated below. Some of the battery design options that result in volumetric. Therefore, it is important to first calculate the total kilowatts required to operate the particular ups at a given load usually assuming full load. How to size a ups correctly for its application kohler. Apc ups selector calculator find the correct battery backup united states select your location. Following our previous guide on calculating the right ups capacity for you, today we move on to the next part in the series. Battery sizing calculation solved example electrical academia. Select highest battery capacities per unit to reduce the number of battery strings in parallel for better charge balance. Specifically, they should follow the six steps below.
About us supplier of superior quality stationary backup battery power products, ups rentals and services that maximize critical power integrity and customer satisfaction. Quickly find ups solutions for your specific protection needs. Selection and sizing of batteries for ups backup ametek. Unsuitable sizing of the battery can pose many serious problems such as permanent battery damage because of overdischarge, low voltages to the load, insufficient backup times. The purpose of the battery is to provide dc power to the inverter of the ups when the mains fail and becomes an important component. May 30, 2011 the calculations done on this post were based on the amperehour method for sizing battery capacity with reference to ieee 485 and ieee 1115. The ups continues to utilize battery power until the ac input returns to normal tolerances or the battery runs out of power, whichever occurs sooner. Ups battery handbook the main characteristics of ups battery. Battery storage systems schaedler yesco distribution. Utilities switch gear black start power plant substation. Capacity ah total daily load x days of autonomy x design factor the design factor depends on the battery s average temperature during the coldest time of the. Batteries which will be operated at higher or lower temperatures continuously should be calculated specifically for that temperature. This paper describes the main components and functions of a battery system, and discusses the reasons why vendor pre.
The calculation is based on the amperehour method for sizing battery capacity rather than sizing by positive plates. How to calculate the right battery size for your ups guide. Abbs first choice for battery technology is an lib cabinet solution with a special combination of lithium manganese oxide and nickel manganese. Bridging supply for ups applications data centers hospitals wafer fabs, etc. Ups selector, ups sizing calculator, choose the right ups eaton. Dc current x duration in hrs capacity of battery ah %age capacity utilization ups kva x x load power factor 1. Sizing the battery for the right application is key to battery longevity and site reliability sizing should take into consideration the environment, aging factor, potential site growth sizing margin under sizing a battery will lead to.
Although this is quite simple, an engineer should be capable of performing a straightforward hand calculation either to confirm the results of a software. Your ups or battery supplier can assist you with these calculations. Please select united states afghanistan aland islands albania algeria american. During a battery discharge the battery supplies constant power to the inverter of the ups. The dc input voltage to the inverter decreases during the discharge. Usually the ups battery load is provided in terms of kilowatts kwb along.
The battery capacity is therefore limited to the size of the charger. This guide is intended to inform the user of the various battery technologies available and some of the design points to be considered when selecting a battery for ups applications. A ups battery size can be be calculated using the formula. In case of a severe overload of the inverter, or a failure of the rectifier or inverter, the static switch bypass path is turned on quickly, to support the output. Ups selection, installation and maintenance guide photo credit. Fill out this quick form and well be in touch within 24 hours to help you find the right ups. The typical table is for 12 v batteries six cells of 2 v each.
Shorter run times deeper depth of discharge shorter battery life. Six considerations to achiving generator ups harmony 9 how to size a ups 10 headto head ups comparison for network closets and server rooms11 ups cost justification worksheet 12 ups form factors input plugs and output receptacles 14 ups startup 18 the difference between va and watts 16 9 ways beer and upss are alike 17 ups vs. These relate to correctly sizing the ups, reliability, environment, total cost of ownership, ups installation, and using and maintaining the ups. Calculating cable size required for ups installation. Ieee guide for the selection and sizing of batteries for. Battery rating calculation the formula employed rating calculation is as stipulated below. Ups selection, installation and maintenance guide eep. Calculations are based on the full rating of the ups anything other than full load will affect the inverter efficiency and warrant the calculations inaccurate. The focus of this calculation is on standard leadacid or nickelcadmium nicd batteries, so please consult specific supplier information for other types of batteries e. This calculation deals with the sizing of an ac uninterruptible power supply ups system i. Upss cannot accommodate an infinite battery capacity.
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