Generators
Standby and Portable Electric Generators
Standby and portable electric generators can provide peace of mind during Montana’s unpredictable weather and occasional power outages. Whether used for short-term convenience or long-term backup power, generators must be installed and operated correctly to protect your family, your property, and electric utility workers.
Missoula Electric Cooperative (MEC) supports members who choose to use generators and asks that all generators be installed and operated safely and in compliance with electrical codes and Cooperative requirements.
Request a peak load study for sizing a standby generator
Before You Purchase a Generator
Before purchasing a generator, consider how you intend to use it. Thoughtful planning will help you select the correct size and type of generator and avoid safety issues or equipment damage.
When choosing a generator, consider:
- What you want to power (essential appliances only or multiple circuits)
- How long you expect to run the generator
- Fuel type availability (gasoline, diesel, natural gas, or propane)
- Noise levels and placement requirements
- Whether the generator will be portable or permanently installed
Oversizing or undersizing a generator can lead to poor performance, equipment damage, or unsafe conditions. A licensed electrician or generator professional can help evaluate your needs.
Notify MEC if You Have a Generator
Please notify the Missoula Electric Cooperative office if you have a generator installed on your property.
📞 (406) 541-4433 or (800) 352-5200
This information is noted on your account to help protect MEC lineworkers during outage restoration. Even generators that are rarely used should be reported.
Types of Generators
There are two main types of generators commonly used by members:
Portable Generators
Portable gasoline or diesel generators provide temporary power where utility service is unavailable. They are often used for:
- Emergency backup for individual appliances
- Construction or job sites
- Camping or recreational use
Important safety considerations:
- Portable generators are not designed to power an entire home
- They should never be connected to a home’s electrical panel
- Overloading can damage the generator and connected equipment
- Low voltage output can harm sensitive electronics
- Never operate a portable generator indoors, in garages, or near windows or doors due to the risk of carbon monoxide poisoning
Use only heavy-duty extension cords rated for outdoor use and the intended electrical load.
Generator Safety Sheet courtesy of NFPA (PDF)
Standby Generators
Standby generators are permanently installed systems that typically operate on natural gas or liquid propane. These generators are designed to provide backup power to selected circuits or an entire home through the building’s electrical system.
Key features include:
- Permanent outdoor installation
- Connection to home wiring through a manual or automatic transfer switch
- Automatic systems detect power loss and start without user intervention
- Greater capacity than portable generators
Standby generators must be installed by qualified professionals and inspected according to local codes and Cooperative requirements.
Request a peak load study for sizing a standby generator
Transfer Switches and Backfeeding Safety
Backfeeding — A Dangerous and Illegal Condition
Any generator connected to a home, farm, or business electrical system must use an approved transfer switch. This is required by the National Electrical Code (NEC Article 702.6) and all electric utilities.
A transfer switch:
- Physically disconnects your electrical system from MEC’s power lines
- Prevents electricity from flowing back into the grid during an outage
- Protects lineworkers from potentially fatal electrical hazards
- Prevents severe damage to your generator when utility power is restored
Never attempt to power your home by plugging a generator into a wall outlet or breaker panel without a transfer switch.
Carbon Monoxide Safety
Generators produce carbon monoxide, a colorless, odorless gas that can be deadly.
To reduce risk:
- Always operate generators outdoors only
- Keep generators far away from doors, windows, and fresh-air intakes
- Never operate generators in enclosed or partially enclosed spaces
- Ensure the generator has adequate ventilation
Install carbon monoxide detectors in your home, especially near sleeping areas.
Water and Electrical Safety
Electricity and water are a dangerous combination.
- Never operate a generator in standing water
- Do not touch a generator with wet hands
- Stand on a dry surface when operating the unit
- Ensure proper grounding as specified by the manufacturer
Fuel Storage and Handling
Proper fuel storage is essential for safety.
- Store fuel in approved containers only
- Keep fuel away from heat sources and open flames
- Store fuel out of reach of children
- Never refuel a generator while it is running or still hot
Additional Safety Reminders
- Inspect your generator before each season of use
- Perform routine maintenance according to the manufacturer’s instructions
- Only qualified technicians should perform repairs
- Never bypass or remove safety devices
- Engine components can become extremely hot—avoid contact
- Keep children and pets away from operating generators
- Always disconnect from utility power before starting any backup generator
For questions about generator installations, transfer switches, or Cooperative requirements, please contact Missoula Electric Cooperative. We are here to help you stay safe and prepared.
