Adding Circuits to a Sub-Panel

How can I add more circuits to a sub panel? I want to add four more circuits to my electric panel box. How to Add Circuits to a Panel and Determine the Number of Circuits That Can be Added to a Sub Panel.

Installing Electric Circuits for a Sub Panel
Electrical Question: How can I add more circuits to a sub panel?

I have a 60 amp breaker panel in a small 8oo square foot house with a natural gas furnace and natural gas water heater. I want to add four more circuits for a dryer, dishwasher, and two 15 amp circuits. There are nine open spots left in the electric panel. If I add these four circuits will I still be within code for a 60 amp panel?

Background: Tom, who is a Handyman from Ottawa, Ontario Canada.
Additional Comments: Very Informative!

Dave’s Reply:
Thanks for your electrical wiring question Tom.

How to Add Circuits to a Sub Panel

Application: Adding Sub Panel Circuits.
Skill Level: Advanced – Best installed by a Licensed Electrical Contractor or Certified Electrician.
Tools Required: Electricians pouch of hand tools, voltage tester and protective safety gear.
Estimated Time: Depends on the make and model of the sub-panel and the condition of the existing electrical circuit breakers and the wiring methods.
Precaution: For safety the main circuit breaker should be turned off or any other disconnect means that would turn off the power to the panel before replacing a circuit breaker, however turning off the main circuit breaker may not turn off the power to all of the areas of the sub-panel components and wiring. This is an extensive project that requires experience and should be performed by a Licensed Electrical Contractor.
Notice: Making changes to electric sub-panel or electric circuits should be done according to local and national electrical codes with a permit and be inspected. Geographical Application: All areas of the World and all Foreign and Domestic Electrical Systems.
Do you need more circuit breaker space? See how to add a sub panel to an existing main panel.

Determine the Number of Circuits that Can be Added to the  Sub Panel

The Space Capacity of a Sub Panel

• For Example: The capacity of allowed circuits for a 60 amp sub panel is not just based on the available openings for circuit breakers.
• The stated Maximum Amperage Rating of a sub-panel does not mean that the sub-panel has been wired for the stated rating, therefore the actual feeder circuit supplying the power should be verified.
• The sub-panel must be load tested or verified to see if it has the available amperage capacity for additional circuits.

Determine the Proposed Circuit Loads for a Sub Panel

The Amperage Capacity of a Sub Panel

• Identify the existing circuits: What they are being used for.
• What is the amount of Current Load of these existing circuits: The type of equipment that is being used.
• Identify the proposed amperage load: Does the sub panel have enough additional load capacity.
• IMPORTANT: Plan the additional circuits so the sub panel will not become overloaded to the point of exceeding the capacity of the feeder circuit.

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» You Can Avoid Costly Mistakes! « Here's How to Do It: Wire It Right with the help of my Illustrated Wiring Book Great for any Home Wiring Project. Complete Guide to Home Electrical Wiring Perfect for Homeowners, Students, Handyman, Handy Women, and Electricians Includes: Wiring GFCI Outlets Wiring Home Electric Circuits 120 Volt and 240 Volt Outlet Circuits Wiring Light Switches Wiring 3-Wire and 4-Wire Electric Range Wiring 3-Wire and 4-Wire Dryer Cord and Dryer Outlet How to Troubleshoot and Repair Electrical Wiring Wiring Methods for Upgrading Electrical Wiring NEC Codes for Home Electrical Wiring ....and much more.

Be Careful and Be Safe - Never Work on Energized Circuits!
Consult your Local Building Department about Permits and Inspections for all Electric Wiring Projects.

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