Choosing the Right Portable Generator for Your Construction Business

In today’s market, the availability of portable power products, namely portable generators, is limitless. Many brands offer similar products since companies use comparable engines, alternators and other components to manufacture a variety of high quality generators that come with a range of price options.  As a manufacturer, the most common question we get is, “What size generator do I need?”  The most important factor when purchasing a generator is knowing what total wattage is required for the equipment you need to power. Other factors to take into consideration is how often the generator will be used, the length of time the generator will be running for each application, if noise is a concern and the cost.

Determining the required wattage of what you want to power may take some research.  A good place to start is the nameplate. Every tool, appliance and apparatus displays the product’s wattage on its nameplate. If wattage is not shown, but amps and volts are given, the following simplified formula may be used:  Amps X Volts = Watts. For example, if the machine uses 14.2 amps and 120 volts, multiply those two numbers to find the amount of required wattage, which in this case is 1,704 Watts.

The biggest mistake customers make when determining what size generator they need has to do with capacitor-start motors. The amount of power a capacitor-start motor needs to start up is underestimated because they require anywhere from four to six times the running watts. Make sure you take into consideration the continuous wattage available and not the maximum wattage available.

All things considered, you may ask yourself, “What really makes one generator more expensive than the next?” Like anything else, the quality of the components, such as the engine and alternator will typically determine the cost of the machine. Although it is usually best to stick with brands you know and trust, make sure you select a generator with an engine having a low-oil shutdown.

Another factor to consider is the insulation class which refers to the amount of heat the unit can take. Insulation classes can also be found on the nameplate and range from A to H with H being the highest class possible. The insulation class becomes a vital element if you are planning constant use of your generator.  

Safety certification is always important when purchasing any equipment, and generators are no different. Look for certifications from organizations like CSA, ETL or UL to ensure that the product you are purchasing has been properly tested and approved by qualified testing facilities. Products must meet rigorous standards for electrical safety and electromagnetic emissions in order to comply with OSHA’s regulations.

The most common style of generators is the open frame generator. With a decibel rating ranging from 72 to 84, these units produce the same amount of noise as a riding lawnmower and are typically used on construction sites, in service vehicles or for general rental applications. Units range from 2,500 to 13,000 watts and can feature options like electric start, wheel kits and lifting hooks. When deciding on an open-frame unit, make sure service items are easily accessible. This will come in handy when you have to change the oil or clean an air filter. Also make sure you pay attention to the fit and finish of the machine. Is the frame powder-coated, does it have an hour or volt meter, are fuses conveniently located and are the alternator and engine insulated and mounted to the frame?

Now that you’ve determined what generator will best suit your needs, where to purchase will be the next decision to make. If you decide to buy the product from an equipment dealer, you will find that they can provide the appropriate replacement parts repair and tune-up services to keep your new unit clean and running efficiently. If you decide to make your purchase from a mass retailer, make certain that the owner’s manual and manufacture’s number is obtainable, in case you need them for future correspondence. If you invest the time to do a little research before you make your portable power purchase, your investment will last many years to come.

Construction Business Owner, July 2010