More generally, load factor is the average demand divided by any number of peak demands, such as load factor at the time of system peak and load factor at the time of noncoincident peak. Demand factordiversity factorutilization factorload. Two simulations were performed and a difference of 7% was identified on the peak cooling load of the building with and without the use of diversity. Demand factordiversity factor utilization factor load factor 1 demand factor demand factor maximum demand of a system total connected load on the system demand factor is always less than one. These terms are diversity factor and demand factor. The demand factors are according to number of dwelling units. Admd is used for mvlv transformer sizing and to calculate voltage drop over the lv feeders, service. The coincidence factor takes account for this behavior calculating the demand of. Since then, many things have changed, but the primary requirement remains the same service equipment and conductors must be sized to handle the. The diversified load is the combination of each devices full load capacity, utilization factor, diversity factor, demand factor and the load factor. Lcl icl quantifying demand diversity of households final.
The effect of diversity changes with the number of customers and evens out. In such cases, in addition to eliminating the diversity factor, we recommend increasing the adjustment factor by multiplying the recovery demand by 1. 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. Introduction this paper is to provide information to contractors, engineers, and others in developing andor understanding an electrical plan for buildings. Electrical power plans for building construction a. Diversity factor and peak load vs block load ps mechanical op 22 may 17 06. Lighting demand factor demand interval factor x diversity factor. Hvac cooling load calculations and principles sensible heat gain is the energy added to the space by conduction, convection andor radiation. Mike gestwick national renewable energy laboratory arlan burdick, anthony grisolia ibacos, a. The maximum demands of the individual consumers of a group do not occur simultaneously. Diversity factor is the ratio of the sum of the individual maximum demands of the various subdivisions of a system or. Loss factor average power losspower loss at peak load. The residential load has the highest diversity factor. When you talk about diversity, there are naturally more than one or many loads involved.
Electrical load calculation is one of the earliest tasks during electrical power. Load factor it is the ratio of the average load to the maximum load for a certain period of time. As with dwellingunit load calculations, general lighting is computed using outside dimensions. Sep 14, 2017 diversity factor varies from system to system and equipment. In a building, the whole load of electrical wiring installation doesnt use at the same time. Simply select an operating mode and enter a value between 0 and 1 for the ks parameter. Diversity factor sum of individual maximum demand maximum demand. The noload factor m, present in the cenelec r064003 technical report, has been eliminated from all equations in the cenelec tr50480 technical report. Calculation of diversity factor and demand factor 082010 6.
Electrical power plans for building construction basics for electrical load calculations i. In the same manner, it is possible to compute the diversity factor on a substation, a transmission line or a whole utility system. Difference between load factor vs demand factor vs diversity factor. While this is analyzed and documented by laboratory planners during the programming phase of design, the actual quantity. The diversified load is the total expected power, or load, to be drawn during a peak period by a device or system of devices. In one office or sleeping room i put 4 power sockets on a 32 amp ring circuit. It is ratio of average load to maximum demand during certain period of time e. The load factor is called daily load factor if the period of time is a day, and if the period of time is a month, the load factor is called monthly load factor, and. Load forecasting load forecasting impacts on the whole network plan, as well as capital expenditure. Hence diversity factors df will be applied to the demand loads when calculating the required ampacity of service and feeder conductors, distribution. Comparing load duration curves with and without peak load 3. Calculation of diversity factor and demand factor cr4. The load factor provides an indication of how well any customer is utilising any utility asset. Furthermore, there will be a brief look at the load flow result analyzer.
The calculation you work out here is just the demand load for the apartments. It is the individual maximum demand load of a customers buildings unit usually. When considering the thermal loads and the diversity factor of a facility containing. The load factor is the ratio of the average load over a designated period of time, usually 1 year, to the maximum load occurring in that period or equation. Can any one please forward me the writeup regarding diversity factor and demand factor. Two simulations were performed and a difference of 7% was identified on the peak cooling load of the building with and without the use of diversity factors. Now you are going to show you one practical example of diversity factor.
If the individual loads do not occur simultaneously usually they do not, the diversity factor will be greater than unity. Diversity factor in electrical wiring installation. Demand factors should be ideally applied to individual loads and diversity factor to a group of loads. Required flow rates are defined based on a fixture. National electrical code nec and similar worldwide regulatory bodies also recognize this fact and allow electrical system planners to add up nameplate data for anticipated loads and multiply by a diversity factor, anticipating that not all devices are running at full load 100% of the time. Diversity factor sum of individual maximum demands maximum system demand 1. Diversity factor varies from system to system and equipment. Guidance on the calculation of diversity is under consideration. I am a yank electrician, i cant find where in 16th or 17th edition you have the diversity factor for calculating loads. Impact of diversity factors on hvac load calculations.
Preliminary load calculation based on building type, sf, nec lighting and receptacle loadsdemand factors, hvac, and specialty equipment sf method electrical loads nec loads lighting loads are continuous so the demand factor is 125% 956 125% receptacle demand factor 100% for first 10 kva and 50% for remaining kva. Cooling and heating load calculation principles, by curtis pedersen, daniel fisher, richard liesen, and myself. In other articles applying to the calculation of loads in specialized. This course provides a procedure for preparing a manual calculation for cooling load. Note that motor loads are not included in this calculation as the 125% factor is already included in the applicable sizing per. Two sets of diversity factors, one for peak cooling load calculations and one for energy calculations will be developed. 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. Other items, such as a sign outlet where required and show windows if present are part of the nondwelling load. Please could you have a look at this for me, and comment. Thus mathematically, load factor may be written as load factor average load maximum demand load factor is generally calculated for a day, month or year. Pdf residential load models for network planning purposes.
Load factor average load peak load load factor is nothing but how well we utilize the energy, and it is the calculation of electrical energy utilization throughout a given time to the utmost energy which has been used in that time. 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. What is diversity factor in electrical wiring installation. Calculate the feeder demand load for dryers at 100% of the appliance rating. This is especially the case with equipment loads, for which there is uncertainty about several factors. This page compares load factor vs demand factor vs diversity factor and mentions formulas or equations of them. Diversity factor is mostly used for distribution feeder size and transformer as well as to determine the maximum peak load and diversity factor is always based on knowing the process. The diversity factor is the reciprocal of the coincidence factor or equation. Industrial loads have low diversity factors usually of 1. What is diversity factor in electrical calculation answers. The industrial load is 1500 kw, the domestic load is 100 kw and the municipal load is 50 kw. Other metrics such as the diversity factor and diversified household peak load are also used for. Load factor is generally calculated for a day, month or year.
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. Electrical systems existing conditions and building load. Hunter observed that all fixtures are not used simultaneously. Diversity factor ks switchgear status and operating modes. What is an explanation for the calculation of a diversity. Residential service calculations in the national electrical. The ratio of the average load over a designated period of time to the peak load occurring in that period, i. Where to use demand and diversity factor request pdf.
Introduction to electrical power requirements for buildings. The period of time a day, the load factor is a daily. Hunters method of estimating load in plumbing systems is based on assigning a fixture unit weight fu to the plumbing fixtures and then converting these to equivalent gallons per minute, based on the theory of probability of usage. Diversity factors of 75% and 70% were applied to lighting and receptacle gains, respectively. Similarly, load factor for a month or year is calculated considering average load and maximum demand for month or year.
If we calculate the load factor for a day then average load as well as maximum demand for the day shall be considered. Compilation of diversity factors and schedules for energy and cooling load calculations, ashrae research project 1093, phase iii draft report, compilation of diversity factors and load shapes. It was in the 1933 nec that load calculation requirements began to resemble a format that the modern code user would find familiar. Both criteria focus on the use of probability theory with a safety factor to compensate for unknown variables. In load calculations, continuous loads should therefore be multiplied by 1. Another factor that you need to consider is the house panel for the loads not found in the individual apartments, such as corridor lighting, outside lighting, parking lot lighting, sign lighting, or maybe even a sprinkler system. The load factor can be calculated by using the following load factor formula. Running load flow analysis click the load flow analysis button on the mode toolbar to switch to load flow analysis mode. The unit values herein are based on minimum load conditions and 100 percent power factor and may not provide.
Load factor is defined as the ratio of average load to the maximum demand for a given period of time. New developments in data and methods have led to numerous revisions. Some people get to the office early while others stay late. Load factor vs demand factor vs diversity factor formula. Chapter three load curves the curve showing the variation of. Demanddiversity factor value quick reference electrical. If one has a low load factor it means that the customer has a very high peak load for a very short period.
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. Latent heat gain is the energy added to the space when moisture is added to the space by means of vapor emitted by the occupants, generated by a process or through air infiltration from outside or adjacent areas. What is load factor definition, calculation, example. Diversity factor and operating mode for distribution btss and busbars, it is possible to set a diversity factor for each type of operating mode. Some conventiontype hotels are being designed to accommodate three or four people per room, using rollaway beds. Thus, there is a diversity in the occurrence of the load. Diversity factor or simultaneity factor is the ratio of the sum of the individual noncoincident maximum loads of various subdivisions of the system to the maximum demand of the complete system. Load calculations in the national electrical code have evolved over many decades. The maximum demand for the power transformer is kw. For this tutorial you should select example project ansi option when starting etap demo. The fire pump only runs for 30 minutes when tested which is once a month after hours.
This is also known as peak coincidence factor nyserda 2008. A power transformer is connected to the following loads. Calculation of lvsource phase impedances, based on ik3max. 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. The ratio of average energy savings to peak energy savings. It is better to evaluate the pattern of usage of the loads and calculate an acceptable diversity factor for each particular case. Using the data for saudi arabia load calculation for residential and commercial buildings.
Residential township load forecasts focus on admd forecasting over a 15 to 20year period, which reflects the economic life of the plant. The load calculation applications manual, also sponsored by tc 4. If each individual load operated to its maximum extent simultaneously, the maximum demand for power would be equal to the connected load and the diversity factor would. There are two terms that seem to confuse designers. If the dryers run continuously, you must size the conductor and protection device at 125% of the load 210. In other words, we do not use all the loads at once at home i. Diversity factor and peak load vs block load hvacr. May 15, 2018 now you are going to show you one practical example of diversity factor.
The lower the demand factor, the less system capacity. Using the data for saudi arabia load calculation for residential and. Estimating load with known diversity factors i am going through old installation rules exam papers with no answers provided, and i attempmted to do one of the calculations as per topic title. Water system planning criteria 34 vallecitos water district master plan november 2010 calculating water demands for schools and hotels water demands at schools, including palomar college and california state university san marcos, shall initially be calculated based on the areabased duty factor given in table 32. Chapter two generation and distribution factors fig. Find the load factor and the diversity factor of the total system. A number of published methods, tables and charts from industry handbooks, manufacturers engineering data and manufacturers catalog data usually provide a good source of design information and criteria in the preparation of the hvac load calculation. Since then, many things have changed, but the primary requirement remains the same service equipment and conductors must be. Aug 25, 2018 the load factor provides an indication of how well any customer is utilising any utility asset.