Introduction to Load Flow
This calculator is commonly used for load listing, load calculations and generator size selection.
Values used in calculations
Loading factor
Ratio between Absorbed Power and Rated Power
| Load Factor | |
| Motors between: 0kW – 15 kW | 0.7 |
| Motors between: 15kW – 45 kW | 0.75 |
| Motors between: 45kW – 150 kW | 0.83 |
| Motors larger than 150 kW | 0.85 |
Efficiency
Percentage between Output Power and Input Power
| Efficiency | |
| Motors between: 0kW – 15 kW | 0.85 |
| Motors between: 15kW – 45 kW | 0.89 |
| Motors between: 45kW – 150 kW | 0.91 |
| Motors larger than 150 kW | 0.94 |
Power Factor
Ratio between Active Power and Total Power
| Power Factor | |
| Motors between: 0kW – 15 kW | 0.75 |
| Motors between: 15kW – 45 kW | 0.8 |
| Motors between: 45kW – 150 kW | 0.82 |
| Motors larger than 150 kW | 0.91 |
Calculations:
- KW Consumed by a Motor = Absorbed Power x Efficiency x Power Factor
- KVAR consumed by a Motor = KW x tan (cos-1(p.f))
- KVA consumed by a motor = (KW2+ KVA2)1/2
- Multiplication Factor for Continuous Load = 100%
- Multiplication Factor for Intermittent Load = 50%
- Multiplication Factor for Stand by Load = 10%
- Max. Normal Operating Load = 100% of Continuous Load + 50% of Intermittent Load
- Max. Peak Operating Load = 100% of Continuous Load + 50% of Intermittent Load + 10% of Standby Load or Biggest individual standby
- Normal Operating Load with Growth Factor = 110% of Max. Normal Operating Load
- Peak Operating Load with Growth Factor = 110% of Max. Peak Operating Load
- Generator Size on 70% Load Factor = Peak Operating Load with Growth Factor / 70%
| Software: | Load Listing, Calculations and Generator Sizing Spreadsheet |
| Version: | 1.0  |
| Developer: | Shafqat Ali |
| Size: | 20.44 KB |
| Price: | Free |
| Download: | Here 🔗 (Get Premium Membership) | Video Courses | Download Updates |
Yes.
I think also there’s an error on absorbed power, how can absorbed power be less than rated power !?
How to download spreadsheet?
PLEASE SHARE AN EXPLANATION OF HOW THE DATA ON COLUMNS F, G, AND H, COME OUT.
Hi Thanks for making things easy by developing such spreadsheet.
Is the formula of the consumed power in the above list of calculations correct?
It seems to me that the cos phi should be left out of it. It is also not taken into account in the Excel file for the calculations of the kW.
nice article ,
just im confused about the absorbed and consumed ,
normally
the total power consumed (KW) = absorbed (KW) (required to the pump) / motor eff factor
Which standard (IS, IEC, NEMA) are used Load factor & power factor values? I have efficiency data as per IS 12615.
The unprotect feature to save as unprotected file does not work if the copy you are creating is already protected. Is there any way to get the password so that the sheet can be expanded upon? It isnt changing the source calculations, formatting, etc. but you cant expand upon it in any way such as when you have 56 loads.
Seems like a lot of work to figure out loads of every appliance you want available. Obviously, one would not be using them all at once. I thought that the way to figure load was to take the total breaker amps times a reduction factor times voltage equals the generator wattage size required.
If so, what is the typical reduction factor?
Thanks, Bill
Effect of Starting sequence and nature of starting for Motor load have not shown in the spread sheet
i cannot edit the excel sheet, it is protected and asking password, please give me the password
Bonjour ,vous copie la feuille Excel dans une autre feuille Excel en suite renomme la feuille Excel
i would like to receiver all articular related to electrical to my above specified E-mail ID
hi,thanks for good software and articles.
but some of these EXCEL Sheets are protected and we cant enter data for calculations please help me.
Thanks again.
Create a copy…
Go to,
Sheet 1,
Move or Copy,
Tick Create a copy
Click on drop down menu and select New Book
…save an unprotected file…