Planning Electrical Circuits Written by: Ryan Talton

Planning for the SEP and/or Sub panel SEP should always be located near the service entrance Might want to place the SEP close to large appliances and equipment that will require most electricity Should be accessible at all times Try to anticipate future needs when finding site Never have SEP in clothes closet or bathroom Box Should be installed 40-48 inches above floor level Can be installed flush or surface mount.

Outlet Spacing Overhead Lighting Wall Outlets (Receptacles) May be placed in discretion of owner In single overhead light should be in center of room Wall Outlets (Receptacles) No point on a unbroken wall measures greater than 6 feet This includes wall space of 2 feet or more in width Unbroken by doorways, fireplace, etc. Most receptacles should be 12 and 16 inches above floor level

Kitchen Countertop Outlets (Receptacles) Should always be installed at each counterpace no wider than 12 inches Should be installed within 24 inches of each other on countertops No more than 18 inches above countertops All kitchen Receptacles should be GFCI protected We will learn more about this later

Closet and Storage lighting Outlets Surface mounted incandescent fixtures should be located 12 inches between fixtures and storage area Surface mounted fluorescent- may be mounted within 6 inches of storage area If recessed- both can be 6 inches from storage area.

Planning Small Appliance Branch Circuits Determine the number of circuits necessary to meet wiring plan requirements Larger homes may call for more circuits

What is a Small Appliance Branch Circuit Generally supply power to kitchen counter top surfaces and dining room areas where small appliances are commonly used Coffee makers, fry pans, blenders, toaster ovens, waffle irons

Planning General Purpose Branch Circuits Make up the largest portion of the home wiring system Include all ceiling and wall mounted lighting outlets and most receptacles Not ones for a specific purpose All circuits originate in SEP

How do I Calculate the Required Number of General Purpose Circuits General Rule: One General Purpose Circuit for every 500 square feet 2500 sq ft house= 5 gpc What about a house that is 2240 sq ft 2240/500=4.48 This equals 4.48 gpc Always go to the next highest number when figuring the number of circuits So: 2240/500=5 gpc Only figure the amount of heated space Not garage or porch space

Balancing a Load Why is it important to balance a load? General rules are: 10 outlets per 15 amp circuit General Purpose 13 outlets per 20 amp circuit General Purpose If the above 10 or 13, add another circuit

Example Problem 40’ 50’ Determine the number of general purpose circuits. (1 circuit for every 500’)

Answer to Example 1 40’x50’=2000 sq ft. 2000/500=4 GPC

Example 2 45’ 65’ 20 amp GPC 75 outlets

Answer to example 2 45’ x 65’=2925sq ft 2925/500=5.85 Need 6 circuits 75 outlets / 6 circuits= 12.5 Do we need to add another circuit?

Example 3 35’ Two story house 15 amp GP 55’ 96 outlets

answer 35’ x 55’=1925 sq ft 1925 x 2=3850 sq ft for both floors 3850 / 500= 7.7 Need 8 circuits 96 outlets / 8 = 12 outlets per circuit Do we need another circuit Add 2 circuits Need 10 general purpose circuits which would make it 9.6 outlets per circuit