Backup generators and transfer switches are essential solutions for homeowners and contractors looking to maintain reliable power during outages. Whether it’s due to downed lines from a winter storm, wildfire-related shutoffs, or necessary maintenance, planning ahead with the right backup system can make all the difference during an unexpected loss of electricity.
Understanding Backup Generator Options
There are two main types of backup generators used for residential and small commercial settings: portable and standby units. Each has its own set of applications, pros, and cons.
- Portable Generators: These are movable units that can power select appliances and lights. They’re generally fueled by gasoline or propane and are best for short-term outages or limited loads. Setup involves running extension cords or connecting through a manual transfer switch.
- Standby Generators: Permanently installed outside, these units automatically start during an outage and can power all or most of a home. Standby systems are typically fueled by natural gas or propane and require professional installation, including a transfer switch wired into the home’s electrical panel.
Choosing the Right Size
Proper generator sizing is critical. Too small, and the generator may overload. Too large, and you’ll pay extra for unused capacity. Start by listing essential circuits or appliances—refrigerators, sump pumps, medical devices, well pumps, etc.—and totaling their starting and running wattages. For whole-house standby systems, a contractor can perform a load calculation to recommend appropriately sized equipment.
The Role of Transfer Switches
A transfer switch is an electrical device that safely isolates the generator’s power from utility lines, preventing dangerous backfeed and protecting utility workers. It’s a key component in any backup system, and its selection depends on your generator setup and power needs.
- Manual Transfer Switch: Requires the user to physically flip a switch to redirect power from utility to generator. Common with portable generators and smaller loads.
- Automatic Transfer Switch (ATS): Detects a power outage and automatically switches to generator power, and back to utility when service is restored. Essential for standby generators and for those who require uninterrupted power.
Installation Steps and Checklist
- Select location: Place generators outside, away from windows and vents for carbon monoxide safety. Ensure accessibility for refueling, maintenance, and service.
- Determine wiring needs: Decide if you’ll power the whole house or just critical circuits. This affects the switch and generator size.
- Install transfer switch: An electrician typically mounts the transfer switch near your main panel. For portable generators, a manual switch or an interlock kit may be used.
- Connect fuel source: For standby units, tie into existing natural gas or propane lines, if available. Portable units require refilling of fuel tanks.
- Test system: Run a simulated outage to ensure the generator and transfer switch function correctly and that all selected circuits are powered as expected.
DIY vs Contractor: Making the Right Call
Installing a backup generator and transfer switch involves working with high-voltage electricity, and mistakes can have serious safety consequences. Here are some decision points:
- Portable generators powering a few appliances can often be handled by a skilled DIYer using heavy-duty extension cords.
- Manual transfer switches for limited circuits may be installed by experienced DIYers with electrical knowledge, but check manufacturer instructions and safety protocols.
- Standby generator and automatic transfer switch installations should be handled by licensed electricians due to code requirements and the complexity of integrating with home wiring and fuel sources.
- Permitting and inspections may be required for permanent installations. Always confirm local requirements.
Common Mistakes to Avoid
- Backfeeding: Never connect a generator directly to a home outlet or panel without a transfer switch. This dangerous practice can energize utility lines and put linemen at risk.
- Improper placement: Running generators indoors or too close to windows can cause deadly carbon monoxide buildup. Always operate outdoors, following manufacturer clearance guidelines.
- Neglecting maintenance: Generators need regular exercise, oil changes, and fuel checks. Failing to maintain the system can lead to failure during an outage.
- Inadequate fuel storage: For gasoline-powered units, keep fresh fuel on hand and consider fuel stabilizers to avoid problems during extended outages.
Maintenance and Testing Tips
Backup systems should be tested and maintained regularly to ensure readiness:
- Monthly Exercise: Run the generator (with load, if possible) for 15–30 minutes each month.
- Annual Service: Change oil, check spark plugs and filters, inspect wiring and connections, and test the transfer switch function.
- Fuel Rotation: Replace stored gasoline every few months, or use fuel stabilizer. For propane/natural gas systems, check fuel levels and supply lines annually.
Final Steps and Preparedness Checklist
- Choose a generator and transfer switch that match your specific needs and electrical loads.
- Prioritize safe installation—hire a professional for permanent or complex setups.
- Store user manuals, extra oil, and maintenance tools with your generator kit.
- Regularly test and maintain your backup power system so it’s ready when you need it.
- Review your home’s unique needs before storm season or anticipated outages.
With careful planning and proper installation, backup generators and transfer switches can provide Oregon homeowners, contractors, and DIYers with peace of mind during even the most unpredictable outages.