Diversity factor is the ratio of the sum of the individual maximum demands of the various subdivisions of a system or. In order to account for such variations, the model generates two sets of power demand profiles and subsequent energy consumption figures by utilising a lowend and highend usage diversity factor. In other terms, diversity factor 0 to 100% is a fraction of total load that is particular item contributed to peak demand. Here are the definitions of some of the terms including demand factor and diversity factor related to this topic. Request pdf demand factordiversity factorutilization factorload factor 1 demand factor in iec, max. The maximum demands of the individual consumers of a group do not occur simultaneously. These terms are diversity factor and demand factor. I am a yank electrician, i cant find where in 16th or 17th edition you have the diversity factor for calculating loads. When you talk about diversity, there are naturally more than one or many loads involved. Seems like there is a need for a single machine that has a single feeder and is designed to meter the charge out to several vehicles, while limiting its own full load current.
Demand factordiversity factorutilization factorload factor. Can you explain demand factor and diversity factor in a. Sep 20, 2015 suppose there are 4 fans and two tube lights in a single room, and each component consumes 2a current, so that the total consumption would be 12a. Thus, there is a diversity in the occurrence of the load. Now you are going to show you one practical example of diversity factor. Chapter three load curves the curve showing the variation of. Equipment load factors, use factors and diversity factors.
Electrical engineering edit in electrical engineering the demand factor is taken as a time independent quantity where the numerator is taken as the maximum demand in the specified time period instead of the averaged or. I am planning to have a single phase 16a industrial socket outlet which is the only item in that circuit and has a 20a dedicated mcb. Where to use demand and diversity factor request pdf. Capacity factor is a key parameter in determination of performance of the power plant. What is physical significance of capacity factor, demand. In one office or sleeping room i put 4 power sockets on a 32 amp ring circuit. Calculation of diversity factor and demand factor 08142010 9. Diversity factor is always 1 because sum of individual max. Diversity factor is the ratio of the sum of the individual maximum demands of the various subdivisions of a system or part of a system to the maximum demand of the whole system or part of the system under consideration. The ratio of the sum of the individual maximum demands of the various subdivisions of a system to the maximum demand of the whole system, i. Diversity factor is defined as the ratio of the sum of the individual maximum demands to the total maximum demand on the system. Calculation of diversity factor and demand factor 082010 6.
Demand factor can be applied to calculate the size of the submain, which is feeding a sub panel or a fixed load like a motor etc, individual load. There are two terms that seem to confuse designers. The definition of diversity factor, in one of the textbooks from my msee program, does not mention connected load. Demand factors and diversity factors are used in design. It is expressed as a percentage % or a ratio more than 1. Demand factor maximum demand of a system total connected load on the system demand factor is always less than one.
Estimating the energy consumption and power demand of. Demand factors are more conservative and are used by nec for service and feeder sizing. It is the individual maximum demand load of a customers buildings unit usually occurring during the peak loading period either estimated or measured. Under this definition other issues such as diversity and load factor are automatically accounted for, and only the coincidence factor will be necessary to determine coincident demand reductions from readily observable equipment nameplate rated information. This in turn means that lesser plant capcity is required. Commercial and agricultural loads are characterized by seasonal variations. Diversity factor sum of individual maximum demands maximum system demand. The industrial load is 1500 kw, the domestic load is 100 kw and the municipal load is 50 kw. What is the result of the product of diversity factor and maximum demand. The diversity factor gives us a correction factor to use, which results in a lower total kw load for the ten ac units.
Suppose there are 4 fans and two tube lights in a single room, and each component consumes 2a current, so that the total consumption would be 12a. Demanddiversity factor value quick reference electrical. Feb, 2016 demand factor maximum demand total connected load for example, an oversized motor 20 kw drives a constant 15 kw load whenever it is on. Difference between load factor vs demand factor vs diversity factor. May 15, 2018 now you are going to show you one practical example of diversity factor. Hotels designed primarily for commercial trade rather than tourism will also see a regimented hot water demand, especially at wakeup time. Electrical diversity factor is the ratio of the sum of the individual maximum demands of the various electrical components of a grid to the maximum demand of the grid. Diversity factor is ratio of the sum of the individual maximum demands of the various sub circuit of a system to the maximum demand of the whole system.
Diversity factor the effect of the diversity factor is to reduce the simultaneous maximum demand on the station which means reduce the capital cost of the station for the same individual demand and consequently a lower overall rate for a generation station electric. D g coincident maximum demand of the group of n loads. The demand factor is often implicitly averaged over time when the time period of demand is understood by the context. It is to be estimated before applying any demand factor or diversity factor.
The difference between the demand factor and the diversity factor has been well explained in the links provided in some comments. The diversity factor is the reciprocal of the coincidence factor or. The coincidence factor is the ratio of the maximum demand of a system, or part under consideration, to the sum of the individual maximum demands of the subdivisions or equation. Typically, 5 to 60 min and 30 min are normally used as these are close to the thermal. To better understand the application of these terms when calculating the load for a service or a feeder supplying a facility, one must understand their meaning. This page compares load factor vs demand factor vs diversity factor and mentions formulas or equations of them. Click on document applying demand factor and diversity factor per the nec.
Class of service total connected load kw demand factor % group diversity factor peak diversity factor public building 100 35 1. Demand factor maximum load divided by the connected load. Diversity factor in a distribution network is the ratio of the sum of the peak demands of the individual customers to the peak demand of the network. Hence, the name diversity factor greater diversity factor means lesser maximum demand. It is ratio of average load to maximum demand during certain period of time e. The word demand itself says the meaning of demand factor. Rd recovery demand 40f to 140f tu total number of living units fr flow rate of shower heads in gallons per minute af unit time adjustment factor c diversity factor sr storage requirement.
The maximum demand for the power transformer is kw. Diversity factor sum of individual maximum demands maximum demand of the system. Note that, diversity factor is always more than 1 as sum of individual maximum demand maximum demand. Apr 24, 2018 diversity factor sum of individual maximum demand maximum demand. Demand the load is time dependent as well as being dependent upon equipment characteristics.
More the value of capacity factor better is the performance of plant. Can you explain demand factor and diversity factor in. The nec definition of demand factor speaks of the ratio of the maximum demand of a system to the total connected load. Equipment load factors, use factors and diversity factors as.
Oct 14, 2010 the difference between the demand factor and the diversity factor has been well explained in the links provided in some comments. Calculation of diversity factor and demand factor cr4. The value of the diversity factor of an electrical grid usually exceeds one. There is generally confusion between demand factor and diversity factor. More the value of capacity factor better is the performance. Introduction to electrical power requirements for buildings. Demand factor maximum demand total connected load for example, an oversized motor 20 kw drives a constant 15 kw load whenever it is on.
Electric vehicle charging stations demand factors mike. In telecommunication, electronics and the electrical power industry, the term demand factor is used to refer to the fractional amount of some quantity being used relative to the maximum amount that could be used by the same system. Jul 23, 2014 diversity factor and the demand factor hi, i am working as an electrical engineer and i have doubts regarding the demand factor and the diversity factor when designing commercial building power distribution systems. Diversity factor sum of individual maximum demand maximum demand. Diversity factor is defined as the ratio of the sum of the maximum demands of the various part of a system to the coincident maximum demand of the whole system. The ratio of the maximum coincident demand of a system, or part of a system, to the total connected load of the system, or part of the system, under consideration, i. Loss factor average power losspower loss at peak load. If the energy balance we do for this facility comes out within reason, but the demand balance shows far too many kw for the peak load, then we can use the diversity factor to bring the kw into line with the facilitys true.
A power transformer is connected to the following loads. Where the building is designed and constructed to comply with an energy code adopted by the local authority, the lighting load shall be permitted to be calculated at the values specified in the energy code. Demand factordiversity factorutilization factorload factor 1 demand factor demand factor maximum demand of a system total connected load on the system demand factor is always less than one. As the amount of demand is a time dependent quantity so is the demand factor. Industrial loads are base loads and are little weather dependent.
Demand factordiversity factorutilization factorload. Northeast energy efficiency partnerships neep defines it as, the ratio of the average hourly demand during a specified period of time of a group of electrical appliances or consumers to the sum of their individual. Mar 21, 2007 the nec definition of demand factor speaks of the ratio of the maximum demand of a system to the total connected load. Diversity factor is ratio of the sum of the individual maximum demands of the various sub circuit of a system to the maximum demand of the whole. Diversity factor and the demand factor iet engineering. The demand factor is always less than or equal to one. Load factor vs demand factor vs diversity factor formula.
Coincidence factor maximum system demand sum of individual maximum demands 1. The diversity factor is applied to each group of loads e. Depending upon how much of this available load you use, the m. These are assumed to be 10% lower and higher respectively than the diversity factor established in the model inputs, accounting for a total. The diversity factor is almost always larger than 1 since all components would have to be on simultaneously at full load for it to be one. Low voltage lv the range of ac voltages up to and including 1 000 v r. Using 1, the relationship between the diversity factor and the demand factor is 33 where tcl i total connected load of load group i df. Man, it seems like there will be gigantic, lightly loaded feeders required, because there will probably be varying degees of demand, but no demand factor allowed.
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