Thumb Rules14 ( Quick Reference DemandDiversity Factor)
April 1, 2018 6 Comments
Diversity Factor (NBC) 

Type of Load 
Type of Building 

Individual House Hold , Individual Dwelling of a Block  Small Shops, Stores, Offices & Business Premises  Small Hotels, Boarding Houses, etc  
Lighting  66% of total current demand  90% of total current demand  75% of total current demand 
Heating and power  100% of total current demand up to 10 A+ 50 % of any current demand in excess of 10 A  100% of full load of largest Appliance + 75% of Remaining appliances  100% of full load of largest appliance+ 80% of second largest appliance + 60% of remaining appliances 
Cooking appliances  10 A +30 percent full load of connected cooking appliances in excess of 10 A + 6 A if socketoutlet incorporated in the unit 
100 % of full load of largest appliance + 80% of full load of second largest appliance + 60% of full load of Remaining appliances  100 % of full load of largest appliance + 80 % of full load of second largest appliance + 60% of full load of Remaining appliances 
Motors (other than lift motors which are subject to special consideration)  100% of full load of largest Motor + 80% of full load of second largest motor  100 % of full load of largest Motor + 50%of full load of remaining motors  
Water heater (instantaneous)  100 % of full load of largest Appliance + 100%of full load of second largest appliance + 25 %of full load of remaining appliances  100 % of full load of largest Appliance + 100%of full load of second largest appliance + 25 %of full load of remaining appliances  100 % of full load of largest Appliance + 100%of full load of second largest appliance + 25 %of full load of remaining appliances 
Water heater (thermostatically controlled)  No diversity  
Standard arrangements of final circuits in accordance with good practice  100 percent of the current demand of the largest circuit + 40 percent of the current demand of every other circuit  100 percent of the current demand of the largest circuit + 50 percent of the current demand of every other circuit 

Socket outlets other than above and stationary equipment other than those listed above  100% of the current demand of the largest point + 40%of the current demand of every other point  100% of the current demand of the largest point+ 75 % of the current demand of every other point 
100%of the current demand of the largest point + 75%of the current demand of every point in main rooms (dining rooms, etc) + 40 % of the current demand of every other point 
After calculating the electrical load on the above basis, an overall load factor of 70 to 90 percent is to be applied to arrive at the minimum capacity of substation. 
Demand Factors (As Per Table 220.42 NEC) 

Type of Occupancy  Electrical Load  Demand Factor 
Dwelling units  First 3000 VA  100% 
From 3001 to 120,000 VA  35%  
Remainder over 120,000V A  25%  
Hospitals  First 50,000 VA or less  40% 
Remainder over 50,000 VA  20%  
Hotels and motels, including apartment houses without provision for cooking by tenants  First 20,000 VA  50% 
20,001 VA to 100,000 VA  40%  
Remainder over 100,000 VA  30%  
Warehouses storage  First 12,500 VA  100% 
Remainder over 12,500 VA  50%  
All others  Total voltampere  100% 
Nondwelling Lighting Loads Demand Factors (As Per 220.44 NEC) 

Type of Occupancy  Electrical Load  Demand Factor 
Nondwelling Receptacle Loads  First 10KVA  100% 
Remainder over 10KVA  50% 
Diversity (The Electricians Guide 5th Edition by John Whitfield) 

Type of final circuit  Type of premises  
Households  Small shops, stores, offices  Hotels, guest houses  
Lighting  66% total demand  90% total demand  75% total demand 
Heating and power  100% up to 10 A + 50% balance  100%X + 75%(Y+Z)  100%X + 80%Y + 60%Z 
Cookers  10 A + 30% balance + 5 A for socket  100%X + 80%Y + 60%Z  100%X + 80%Y + 60%Z 
Motors (but not lifts)  100%X + 80%Y + 60%Z  100%X + 50%(Y+Z)  
Instantaneous water heaters  100%X + 100%Y + 25%Z  100%X + 100%Y + 25%Z  100%X + 100%Y + 25%Z 
Thermostatic water heaters  100%  100%  100% 
Floor warming installations  100%  100%  100% 
Thermal storage heating  100%  100%  100% 
Standard circuits  100%X + 40%(Y+Z)  100%X + 50%(Y+Z)  100%X + 50%(Y+Z) 
Sockets and stationary equip.  100%X + 40%(Y+Z)  100%X + 75%(Y+Z)  100%X + 75%Y + 40%Z 
X = the full load current of the largest appliance or circuit  
Y = the full load current of the second largest appliance or circuit  
Z = the full load current of the remaining appliances or circuits 
Diversity factor for Building (Horizon Power) 

No of customer  Diversity factor 
1  3 
2  2.57 
3  2.2 
4  2 
5  1.89 
6  1.8 
7  1.74 
8  1.71 
9  1.69 
10  1.64 
11  1.61 
12 To 14  1.57 
15 To 17  1.5 
18 To 20  1.46 
21 To 23  1.42 
24 to 26  1.4 
27 To 29  1.38 
30 To 59  1.37 
≥60  1 
Demand Factor (The Electricians Guide Fifth Edition) by John Whitfield) 

Area  Demand Factor 
Office / School  40% 
Technical Blocks / Hospital  50% 
Air Port / Banks / Department Store / Shopping Center / Public Place  60% 
Restaurants / Factories (for 8 Hours Shifts)  70% 
Workshops / Factories (for 24 Hours Shifts)  80% 
Arc Furnace  90 % TO 100% 
Arc Welding  20 % TO 50% 
Compressor  20 % TO 50% 
Conveyor Crane  90 % TO 100% 
Had tool  20 % TO 40% 
Paper Mills  50 % TO 70% 
Induction Furnace  80 % TO 100% 
Demand Factor As per No of Appliances 

No of Appliances  (A) Less than 3.5 KW  (B) 3.5 KW to 8.5 KW  (C) Less 12 KW 
1  80%  80%  8% 
2  75%  655  11% 
3  70%  55%  14% 
4  66%  50%  17% 
5  62%  45%  20% 
6  59%  43%  21% 
7  56%  36%  22% 
8  53%  35%  23% 
9  51%  34%  24% 
10  49%  32%  25% 
11  47%  32%  26% 
12  45%  32%  27% 
13  43%  32%  28% 
14  41%  32%  29% 
15  40%  32%  30% 
16  39%  28%  31% 
17  38%  28%  32% 
18  37%  28%  33% 
19  36%  28%  34% 
20  35%  28%  35% 
21  34%  26%  36% 
22  33%  26%  37% 
23  325  26%  38% 
24  31%  26%  39% 
25  30%  26%  40% 
26 To 30  30%  24%  15KW+1KW for Each 
31 To 40  30%  22%  
41 To 50  30%  20%  25KW+0.75KW for Each

51 To 60  30%  18%  
More Than 60  30%  16%  
Lighting Demand for Building (As per NBC) 
Lighting demand for buildings should be considered as per type of building. 
Where nothing is specified, for lighting demand of any type of building a maximum of 13 W/m2 of all builtup areas including balconies. 
Covered parking areas may be considered at 3.23 W/m2 including balconies, service areas, corridors, etc, may be considered with very basic diversity of 80 % to 100 %. 
Power requirements shall be considered at least 55 W/m2 with an overall diversity not exceeding 50 %. These shall be excluding defined loads such as lifts, plumbing system, fire fighting systems, ventilation requirement, etc. 
Dear jignesh
the electrical articles what are posted is very useful and easy to understand.but i want buy yours electrical pdf book so guide me how to buy.
THANKS & REGARDS
ABDULLAH
Very Handy and Great appreciable Job done.
Thank you!
Thanks Jignesh.
For sharing very very useful notes. Could you please define the term “Current Demand”?
It will be very helpful if a example of load calculations on the basis of information sent by you is made available to us.
Thanks again
Hi Mr.Jignesh,
I am an Electrical Engineer in profession and working in the industry for 4 years. I need your kind advise for a practical problem I am facing. one of our Printing plant have 03 No of sub panel boards which are parallel. Each has several 3ph RCCB(40A,100mA). One specific RCCB from each sub panel getting tripped at once. but just after that we can switched on and work for 10 min and again tripped.these are connected to printing machines which are rotating itself by a motor. I couldnt find any fault there. When I check the harmonics from the DB analyser I noticed that the Nuetral harmonics level is about 187%. Please advice.
B/R Asanka Dilhari(BSc.Eng, Hons) Elec. Eng Jay Jay Mills Lanka (Pvt) Ltd A6, SEPZ Avissawella Sri Lanka
On Sun, Apr 1, 2018 at 5:51 PM, Electrical Notes & Articles wrote:
> Jignesh.Parmar posted: ” Diversity Factor (NBC) Type of Load Type of > Building Individual House Hold , Individual Dwelling of a Block Small > Shops, Stores, Offices & Business Premises Small Hotels, Boarding Houses, > etc Lighting 66% of total current demand 90%” >
THANKS FOR THE POST