Installing your own home electrical system can be a great way to save money, but it requires research, planning, and adherence to electrical codes and safety standards. As a homeowner, you can legally install new wiring circuits and outlets, light fixtures, switches, and other components of a residential electrical system as long as you obtain the proper permits and pass inspections.
Research Electrical Codes and Safety Standards
The first step is to thoroughly research your local and national electrical codes. The National Electrical Code (NEC) provides the baseline standards that local jurisdictions use as the basis for their own codes. Be sure to check with your local building department to understand all permits, inspections, and other requirements. The last thing you want is to install a system that doesn't meet code!
Some key areas to research in the electrical code include:
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Wiring and cable types - specifics on selecting the proper wire gauge for expected electrical load and required insulation and jacket materials.
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Circuit design - regulations on the number of outlets per circuit, use of GFCI and AFCI breakers, and other circuit requirements.
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Electrical boxes and conduit - proper selection of junction boxes, outlet boxes, and conduit type and sizing.
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Circuit labeling and documentation - specifications on providing diagrams, posting warning signs, and labeling breaker panels.
Thoroughly studying the electrical code is a must to ensure you design and build a safe, compliant system.
Create Detailed Plans
The next crucial step is to map out detailed plans for your electrical system renovation. Consider sketching layouts showing all circuits, wires, outlets, switches, lights, junction boxes, and the main breaker panel. The plans don't have to be engineering grade drawings, but should provide enough detail that you or an electrician could follow along during installation.
When designing circuit layouts, follow code requirements on the number of outlets per circuit. For example, most 15A household circuits can contain no more than 10 outlets. This prevents overloading the circuit which can lead to tripping breakers, voltage drops, and possible fires.
Carefully plan the placement of outlets, switches, and lighting fixtures for safety, functionality, and aesthetics. Account for existing appliances and where you may add new loads like a home office when determining your outlet needs.
Purchase Materials and Tools
With detailed plans in hand, make a comprehensive list of all the materials and tools you will need. For materials, specify exact quantities of different wire gauges, conduit type and size, boxes, receptacles, breakers, and other parts.
For tools, at a minimum you will need:
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Voltage tester - to safely check for live wires
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Wire strippers - for removing insulation from cables
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Cable cutters - clean cuts help make solid connections
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Screwdrivers - standard and Phillips head types
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Handsaw or oscillating multitool - for cutting holes and notches
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Hammer - for nailing boxes and driving staples
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Level - for mounting components straight and neatly
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Fish tape - useful for pulling cables through finished walls
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Clamp meter - to measure current flow for troubleshooting
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Personal protective equipment like glasses and gloves - for safety
Purchase commercial grade tools and high-quality materials from electrical supply stores. Avoid cheap hardware store grade products for safety.
Upgrade the Main Service Panel
Before running any new wiring, consider upgrading your main service panel if needed. Older 100 amp or 150 amp panels may not provide enough power for additional circuits. Upgrading to a 200 amp panel is a smart way to allow for expansion and prevent overloading.
Hire an electrician for this complex task which involves safely disconnecting your home from the utility feed before swapping out the panel. Then the electrician can connect the new panel and re-establish power.
Run and Connect New Circuits and Wiring
Now you're ready to install new wiring, outlets, switches, and other components. Follow your plans, and adhere strictly to electrical codes and permit requirements. Key installation steps include:
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Shut off power at the main breaker before working. Test wires for current before touching.
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Select the proper gauge wire for expected electrical load as specified by code.
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Use nail guards when securing cables to studs and joists. Avoid over-fastening.
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Take care not to nick or damage wire insulation and jackets.
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Attach cables firmly to boxes with clamps or connectors. No loose connections.
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Use wire nuts or crimp connectors properly for secure splices.
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Ground all outlets, metal junction boxes, fixtures, and appliances properly.
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Label all wires, cables, and breakers clearly for identification.
Work methodically, test frequently with a voltmeter, and call for inspections at the required stages per your permit. Safety first and quality craftsmanship are critical.
Add Lighting Fixtures, Switches, and Outlets
Finish up by installing all the switches, light fixtures, outlets, cover plates, and other fixtures. Follow manufacturer instructions carefully and use materials rated for damp or wet locations in bathrooms and outdoors. Take time to neaten all visible wiring and ensure components are solidly mounted, level, and plumb.
Flip the main breaker back on once the system is 100% complete. Walk the site testing every light, switch, and outlet. Verify proper voltage, polarity, and grounding using a multimeter. Only minor tweaks should be needed at this point if you followed the plans precisely.
Hire an Electrician for Complex Tasks
As a homeowner, you are allowed to carry out basic wiring projects. However, more complex tasks like upgrading the main panel, running new service entrance wires, wiring detached buildings, and installing generators require an electrician.
While DIY can save money, safety and compliance are paramount. Know your limits, and consult local codes to determine which tasks require a licensed pro. Also consider having an electrician review your plans and inspect the finished work. Smart DIY involves knowing when it pays to hire a pro.
With careful planning, high-quality execution, and adherence to codes, you can take on much of the electrical system installation yourself and save substantially over hiring a contractor. Just be sure to obtain all required permits and pass inspections - the savings are not worth the risk of fire or shock! Use the tips provided here to tackle your next residential wiring project successfully.