MRO Magazine


Power Needs: What to consider when buying a portable generator

In today’s market, there are many things to consider when buying a portable generator — and in most cases, this is a good thing. However, too much choice can also become a problem. Too many options can become overwhelming when looking to buy a machine, especially if this purchase is one of many to be done within a portfolio. Let’s review a few points of consideration.

What Are Your Needs?
Although this is a very basic question — and one that any qualified portable generator salesperson should work with a customer to refine and clarify — it is often also the most difficult to answer as there are many things to consider. To get the most out of a purchase, consider the following factors:

Is the application considered prime or standby power? Generators are rated based on continuous use (prime power) or occasional use (standby power). Consider whether the plan is to use a generator 24 hours a day, 7 days a week or only in emergency situations (such as at a hospital or airport). This component of an application is very important to consider as it can drastically affect the quality and ultimately the cost of the generator. Appreciate that all generator manufacturers design, build and test their machines in relation to their target market and the applications foreseen. A generator designed for limited use is not created, built and tested in the same way for durability and efficiency as that of a unit designed for on-site prime power applications.

Load: Often taken into consideration when sizing the generator, it is important to understand what is going to be powered by your generator. There are many types of loads and factors that affect how the load behaves. Some things to think about:
• Power Factor: Three-phase generator sets are rated for 0.8 loads and single-phase units are rated for 1.0 loads. Lower power factor loads require larger alternators or generators.
• Peak Loads: These are generally caused by equipment that frequently cycle on and off, such as cranes, heating systems and or water pumps.
• Motor Loads: Consider the size, type, starting method and operating current draws.

Maximum allowable voltage and frequency drops: These are often taken into consideration when the equipment being powered is sensitive to significant variations in voltage and frequency.

Altitude and temperature:
Although they are not living beings, diesel engines do “breathe.” Air is either more or less dense depending on altitude and ambient temperature; therefore, engine performance can be affected by either of these two factors. Consider where this machine will operate now and into the future.
Voltage: Consider the ranges required at site both in single and three phase operation.

Daily power-consumption curve: It is always a good idea to map out the daily power requirements hour by hour over a 24-hour period. One finding could be that instead of one big generator, two or three smaller generators in parallel may offer a reduced cost of operation as well as greater reliability and flexibility at a site.

Consultation and education: Regardless of one’s level of knowledge when it comes to generators, it is always a good idea to consult with a local sales representative to see what is new in the market. Manufacturers constantly challenge each other to innovate or to find better ways of getting the job done. Some focus on general areas, such as reduced cost of operation, ease of use and improved safety, whereas others excel at specific application based offerings. Don’t miss out on discovering a new way of meeting an application’s specific needs.

Legislation and Regulations
Regulations that control the safe operation of generators can exist at all levels of government as well as within public and private companies. As a result, it is recommended to consult with local authorities to ensure that a particular product meets the basic requirements. Here are a few questions to ask of a supplier and to review with local regulatory agencies.

Does the unit and all of its associated components meet CSA requirements? (Does the machine bear the CSA label?) This is especially important to consider when importing used generators or machines produced outside of Canada.

Are there any local (provincial or city) power authority regulations that need to be met based on the application? For example, special safety equipment is required for public events.

Is the machine mounted on a trailer? If so, consider if it requires a license plate, an annual inspection or even electric or hydraulic brakes. There are also environmental considerations to be made. Although these may or may not be required by various government entities, many public and or private companies mandate these criteria.

Full fluid containment: In some cases, portable diesel powered equipment when brought to site must have 110-per-cent fluid containment. This means that the frame or “tub” of the machine is capable of containing 110 per cent of the fluids on board. Fluids include fuel, oil, antifreeze and any other liquid that is considered harmful to the environment if it were to get outside of the machine.
Noise: Whether in a residential neighborhood or at a concert, noise regulations may be in place to protect the public. Consider the venue and consult the appropriate authorities to see if any regulations exist in the specific area of operation.

Off-road diesel engine emissions: This is a federally regulated requirement that was released Jan. 16, 2012, by Environment Canada. The regulation specifies that all diesel engines used in off-road applications that fall within a certain horsepower range that are imported into Canada be at the Interim Tier 4 (iT4) levels for particulate matter and nitrous oxides. Although the regulation states that iT4 is the desired emissions level, it also outlined the guidelines for the importation of transition engines (similar to the U.S. EPA rules on the sale of flex engines). Transition engines are engines that only meet Tier 1 through Tier 3 levels and can only be used should specific conditions be met. Consider the following at it relates to your purchase:

• Are you the importer on record?
If so, as a company you are required to file a report annually with Environment Canada stating the number of engines imported and at what emissions level.

• Is the machine new or used?
This can be tricky as there are sometime several dates in play, such as the date the engine was produced, the date the machine was produced and the date the machine was imported into Canada, and it’s critical to know whether or not the regulation applies.

• Does your company actively pursue the most environmentally friendly technologies?
Consider your own companies policies on environmental care and protection.

Consider costs: Although iT4 technology costs more at time of initial purchase, fuel consumption overall is usually better. Will the long-term operational costs outweigh the initial difference in purchase price? Also consider that some iT4 engines require low sulfur fuel, low ash oil as well as additional servicing of a diesel particulate filter (DPF) if so equipped. These are all elements that may be difficult to source or service if the machine is exported to another location where these items are not readily available.

There are many factors to consider when buying a portable generator, and customers are not alone to make the decision. Reputable manufacturers consider all of these elements and can help direct you to the right machine for your application and region. p

Michael Marion is the product and business development manager with Atlas Copco Construction Equipment Canada’s portable energy division. For more information, visit or write to