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STANDBY GENERATOR FREQUENTLY ASKED QUESTIONS

What is an automatic standby generator?

An automatic standby generator is a back up electrical system that operates whether you are home or away. Within seconds of an outage, it automatically supplies power directly to your home's electrical circuit breaker box. After utility power returns, the generator shuts itself off and waits for the next outage. It operates on natural gas or liquid propane gas and sits outside just like a central air conditioning unit.

Why circuits and not watts?

You can simplify the job of sizing a standby generator by matching the circuits between your home’s main electrical panel and the generator system’s load center. On the other hand, figuring out the specific wattage requirements of appliances and other items in your home can be difficult since they are plugged into outlets all over the house. By identifying the circuits to back up you can easily decide how large a generator is needed and what model will best fit those needs. All the identified circuits will have backup power available. A licensed electrician should determine the electrical load and identify the circuits to back up.

What is the difference between an automatic air-cooled generator and an automatic liquid-cooled generator?

The engines. Air-cooled generators come with engines that use fans to force air across the engine for cooling, while liquid-cooled generators use enclosed radiator systems for cooling, similar to an automobile. Generally, liquid-cooled engines are used on larger kW generators due to the larger engines required for the higher power output.

How do I correctly size a generator for my home?

First, envision your home or business without power. Some outages may be short in duration, while others could last for days or weeks. What would you miss during an outage?

Often, generators are pre-packaged with a transfer switch containing a predetermined number of circuits based on the generator's kW power rating. Each circuit is directly connected to a matched circuit on the home's main circuit breaker panel, providing electricity to that specific appliance or area of the home. For example, with an 8kW generator packed with a ten circuit transfer switch, you can connect (1) lights and TV in the family room, (2) microwave and lights in the kitchen, (3) refrigerator, (4) power to the bathroom, (5) computer and home office, (6) garage door opener, (7) air conditioner, and (8) furnace.

The most accurate way is to have an electrician conduct a load measurement of the circuits and items you intend to back up with your standby generator. An amp meter is used to measure the power required as each appliance starts up, when it requires the greatest amount of power. The result of this load measurement gives you the total power requirement for backup power.

What's the advantage of an aluminum or composite enclosure?

Aluminum and composite enclosures are naturally rust and corrosion resistant. For salt air or high humidity conditions, aluminum or composite is highly recommended to ensure decades of worry free service.

Can an automatic standby generator replace utility service?

No...the generator fuel costs would be much more expensive than buying power from the utility company since their cost to produce electricity is divided among thousands of customers.

Can I install the generator myself?

As an option, manufacturers offer systems prepackaged and pre-wired with comprehensive installation instructions. You could perform the simpler site preparation steps and have a professional make the electrical panel and fuel connections, or you could complete the entire installation yourself. However, for safety reasons and to ensure adherence to all local, state and national electrical codes, particularly for non pre-wired or larger systems, we recommend you use an authorized dealer or licensed contractor.

Do they have to be maintained?

Yes, simple maintenance is required. All generators require periodic oil and filter changes to ensure maximum performance for years of reliable service. Preventative maintenance kits are available and many dealers offer annual maintenance contracts for a worry-free ownership experience. Refer to the owner's manual for routine maintenance procedures and schedules.

Can I purchase a service/maintenance contract?

Yes, service/maintenance contracts may be offered by your local installer/dealer. You can inquire with them to determine availability and cost which will be based on the level of service you require. Cost will also vary based on hourly labor rates in your local area.

I don’t have natural gas at my house. How long will a generator run on my propane tank?

Run time will vary with the size of the generator and the appliance load being placed on it. The chart below shows hours of operation for a typical example: a 16kW generator running at half load.

16kW generator at 1/2 load
LP tank size (gallons) 100 250 500 1000
hours of generator operation 50 125 251 503