Thursday, April 23, 2009

When the Lights go Out

How Much Power Do I Need?

There are two basic power measurements for generators: peak power (also known as startup power) and continuous power. Both are measured in wattage.
• Peak power is the wattage required for appliances at startup or when they are running at their highest levels of power consumption.
• Continuous power is the wattage required for operation of those appliances under normal load.

Standby Generators: Standby generators create from 5,000 to 25,000 watts or more of power. You’ll have to choose a generator that supplies sufficient peak and continuous wattage for the appliances on the circuits you need to power.
You can choose between an air-cooled and a liquid-cooled model standby generator. Generally, liquid-cooled models are bigger and create more power.

Portable Generators: A small 1,000-watt portable generator may be all you need for recreational purposes. And you may use up to 8,000 watts if using a generator to power tools on the jobsite. Because you plug appliances directly into a portable generator, you’ll also want to make sure that your model has the number and type of outlets you need. The size of the fuel tank also is crucial. The bigger the tank, the longer your generator can run without refilling and produce power. If you want to use a portable generator to power specific circuits in your house–or the whole house–follow the guidelines for choosing a standby generator.

What Features and Accessories Do I Need?
Aside from pure power production, there are some useful features and accessories to consider when buying a generator.

Transfer switch: If you want to use your generator to power your home, you’ll need a sufficiently sized generator and a transfer switch. The transfer switch safely closes off the utility power line to your house’s electrical system and opens a direct line to the generator and reverses the process when utility power is restored. Standby models can work either with a manual or an automatic transfer switch. The benefit of an automatic transfer switch is that it senses when utility power has been lost and automatically switches to generator power.

Wheeled Frames: As the name suggests, portable generators can be transported to different locations. The smallest portable generators are comparatively light–perhaps 50 pounds–and can be carried. Larger models can weigh as much as several hundred pounds, making a wheeled frame essential for transportation.

Other Considerations:
• Noise: Generators aren’t necessarily quiet. Some offer extra features to reduce the noise created during operation.
• Weather Protection: Make sure the generator you purchase is suited for the climate in which you’ll use it.

How Do I Install and Operate a Generator
Standby Generators: Installing a standby generator by yourself may void the unit’s warranty or violate local building codes, so research these issues before you begin. The basic steps are as follows:

First, mount the unit outside your home on a concrete pad or plastic mounting pads that come with the generator. You may need a expert to pour the concrete foundation and mount the generator.
Next you’ll need to contact your gas or propane company to connect the unit to its fuel source.
Last, you’ll have to call an electrician to hook the generator up to your home’s electrical system. Some generators come with pre-wired kits that make it easier for the “do-it-yourselfer” to do the wiring. In most cases, it’s probably safest and best to have this work done for you.
Once installed, operation depends on whether you’ve used a manual or an automatic transfer switch. With an automatic transfer switch, if the generator senses a disruption in utility power, it turns itself on and takes over power production until utility power resumes. With a manual transfer switch, you have to handle these chores yourself. On a standby model, you’ll have to change the oil and filters on a regular basis. Many manufacturers provide maintenance kits to make this easier.

Portable Generators: If you’re not planning to hook your portable generator into your home or building’s electrical system, there is not a lot of setup involved other than finding a safe place outside your home for the generator. Because portable generators create carbon monoxide, you should never run them inside a building, beneath a window, or near any opening to your house (doors, vents, etc.). Once situated, fill the generator with the required type of gasoline and oil and start the unit. Startup can be as simple as pressing a switch, but on some you’ll have to yank a manual recoil pull-cord. Of course, you will have to plug the appliances you want to power into the generator, refuel it as necessary, and shut the generator off when you’re finished with it.

If you want to connect your generator to your home’s electrical system, you’ll need a manual transfer switch. Make sure your generator’s manufacturer supports connecting your model to a transfer switch. If supported, comply with your model’s safety and warranty guidelines as well any local building codes during the installation. In general, it’s best to hire an electrician to handle the wiring of your home to the generator and transfer switch.

However you use your generator, over time you’ll have to change filters, oil, and spark plugs. Plus, you should not store raw gasoline in the generator when you’re not using it. Either run the generator empty or add a gasoline stabilizer that will prevent the gasoline from “gumming” up. Many manufacturers sell tune-up kits for their models.

How Do I Run a Generator Safely?
• Do not operate generators indoors, in enclosed spaces, or near a window. Make sure there is proper ventilation for all exhaust.
• Follow the manufacturer’s instructions for installation, operation, and maintenance.
• Do not operate generators near combustible materials.
• Operate portable generators on a level surface.
• Do not plug a portable generator directly into your house circuit.• Do not attach a generator’s transfer switch to your circuit box yourself unless you’re very sure of what you’re doing. Check all applicable local, state, and national codes and the warranty information before you do this.

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