1. Single-Phase Vs. Three-Phase Generators: What’s The Difference?

    April 28, 2015 by rwritz
    Single-Phase Vs. Three-Phase Generators: What’s The Difference?
    1 vs 3 phase diagram

    Image from www.tripplite.com

    Single-Phase vs Three-Phase

    Single-phase and three-phase generators provide power differently. The most obvious evidence of this is seen in power delivery. Both types provide AC power, but a three-phase system produces three separate waves of power, delivered in sequence. This ensures a continuous uninterrupted flow of power that never drops to zero and makes three-phase generators more powerful than single-phase generators.

    Single-phase systems deliver one constant wave of power, but the power level varies with the electrical current coming in. That means that power levels can and do drop to zero during the cycle. This happens so quickly that it is undetected by humans and rarely has an effect on whatever device is being powered. In fact, residential power is single phase and there’s never a problem powering devices in our homes. But for very large and demanding power applications, this dip could be detrimental, which is why three-phase systems exist.

    The easiest way to visualize these power differences is to imagine a wave. One single wave (i.e. a single phase system) starts at zero, goes up to the peak, and goes back down to zero before the next wave starts. In a three-wave system, the three waves in sequence each individually look and act the same as the single wave, but since they arrive in sequence, their total power overlaps a bit providing more power than the single phase circuit, keeping that power always above zero, and distributing the total load over three phases/waves so there is less draw on one single wave.

    It All Comes Down To Power Needs

    If you’re questioning whether you need a single phase or a three-phase generator, you need to think about your power needs…and your budget. Single-phase systems are less complex and less costly. They are more common in residential or rural applications where the loads are relatively small. Unsurprisingly, 3-phase systems are more costly to install and maintain, but depending on your power needs, they may be a necessity.

    3-phase systems are ideal for high-capacity settings which is why you usually only see them in industrial and commercial areas. Data centers, in particular, benefit from 3-phase back-up generators due to the increased distribution capacity. 3-phase systems can power multiple racks whereas single-phase systems can’t.

    Learn More About Single And Three Phase Generators At Critical Power Exchange

    If you need to find a power source for your data center or commercial application, contact Critical Power Exchange at 1-877-315-4176. We can help you determine if a single or three-phase system is better for your needs and then help you find the right generator to provide it. Visit us online at www.criticalpower.com to see our current supply of generators.


  2. What’s New With Diesel Generators?

    April 21, 2015 by rwritz
    What’s New With Diesel Generators?

    The generator is one machine that has really withstood the test of time. First introduced over 100 years ago, diesel engines were instrumental in replacing steam engines and their usefulness never stopped. Today they are used for all kinds of operations with no indication that this will change any time soon.

    Since diesel generators remain so popular and will continue to be so, it’s only natural that engineers find ways to enhance and improve the machines.

    Improvements In Diesel Generators

    Some improvements that we’ve already seen in diesel generator include:

    • Engine Efficiency. Like any fuel-based machine, there has been a lot of focus on improving the efficiency of the diesel engine. Since diesel engines need only compressed air and fuel to ignite, the engine’s efficiency is directly tied to how the fuel droplets are added to the combustion chamber. Smaller, widely distributed droplets lead to a more efficient diesel engine. Recent improvements to diesel engines, like automated fuel injection, have maximized this distribution resulting in better performance and power output.
    • Digital Controls. Older diesel engines relied on analog-type controls for operation. Today’s newer designs have digital controls that allow for more precise measurements, fuel injection, and timing. These digital controls improve combustion action and even reduce exhaust. They are invaluable in large-scale operations and provide real-time status updates on generator performance.
    • Emissions Treatments. Technology advances have made it possible to reduce exhaust and emission fumes and gases. Exhaust gas recirculation and selective catalytic reduction both help to minimize emissions.
    • Noise Control. Generators are loudest at start-up. New sound attenuation methods, like sound attenuation pockets in the combustion pre-chamber or adding platinum or rhodium pellets to the chamber, work to reduce this noise.
    • Fuel Treatment. Low-sulfur diesel fuel emits less particulate matter and has lower exhaust emissions than untreated diesel. Not only does this lead to improved air quality, it reduces strain on the engine, which can get clogged from these particulates.

    As generator usage continues, technology advances, and stricter environmental regulations take hold, we can expect to see even more changes and improvements. Possible future changes include:

    • Improved fuel economy
    • Advances in biodiesel technology
    • Improved power output
    • Cleaner exhaust fumes

    Explore Diesel Generators At Critical Power Exchange

    Generators have come a long way since their early days and we can look forward to future changes that will ensure the generator remains a stable and popular choice for power generation.

    To see the latest in diesel generators, visit Critical Power Exchange at www.criticalpower.com.


  3. Understanding Kilowatts Vs. Kilovolt-Amperes

    April 14, 2015 by rwritz
    Understanding Kilowatts Vs. Kilovolt-Amperes
    kw vs kva

    Image from http://www.lesl.co.uk/power-quality.php
    Lawton Electrical Services LTD

    Look at any electrical machine and you’ll find a power rating. This is usually shown as kilowatts (kW), but sometimes you’ll see a kVA, or kilovolt-ampere rating. Although both ratings express power, they are different.

    Kilowatts. A kilowatt is the real or actual power that the machine provides: Voltage x Current. This is the amount of power that a machine can provide based on its horsepower.

    Kilovolt Amperes. A kilowatt ampere is the “apparent” power provided by the machine. It will always be higher than the kW rating, but only a portion of the kVA is available to do the work. In direct-current (DC) situations the kW and kVA are the same because the voltage and the current do not get out of phase. In alternating current (AC) situations, this is not the case. In AC systems, the voltage and current can get out of phase with one another. In that case the kW rating tells you how much actual power is available, the kVa indicates an excess of the current.

    In other words, the kVA is the amount of current a device can draw in while the kW is the amount of power the device puts out.

    The Power Factor

    The difference between the kilowatt rating and the kilovolt-ampere rating is something called the Power Factor. The power factor is a value that varies with every electrical device or machine, somewhere between 0 and 1. The value is expressed with a percentage with 100% representing unity of current. With unity, there is no difference between the kW and the kVA. The closer to 100% that machine rates, the more efficiently it uses electricity, which is where it becomes important when evaluating generators.

    Why kVA Matters

    While the U.S. most commonly uses kW to express power ratings, most of the rest of the world uses kVA. Although the kilovolt-ampere may seem like extraneous data, it really isn’t. You need to know the kVA to ensure your facility has the proper wiring capabilities to carry this extra current, even though the machine won’t be using it. Generators also carry the kVA rating so you can determine if it will be able to handle the extra current for reactive loads.

    Learn More About Generators And Power Supply From Critical Power Exchange

    For more information about gauging generator performance, contact Critical Power Exchange at 1-877-315-4176 or visit us at www.criticalpower.com.


  4. Generator Fuel Types

    April 9, 2015 by rwritz
    Generator Fuel Types

    One of the most important things to think about when choosing a generator is what type of fuel it requires. You’ll need to make sure you can acquire the necessary fuel to run your generator and, in some cases, have a place to store that fuel on site. The different fuel types have different storage requirements, prices, and availability, depending on your geographic location.

    Common Fuel Types

    Gasoline, diesel, natural gas, and propane are the four most common types of generator fuels used today. While you may have heard about biodiesel fuels, they are not widely used in generators just yet, though they may become more widely used in the future.

    • Gasoline. Gas-powered generators have the advantage of using a readily-available, relatively inexpensive source of fuel. However, that ready availability can backfire in an emergency since there will likely be a run on gasoline in those situations and you might find yourself without a source of fuel. Storing gas doesn’t work too well, since it has a shelf life of only 1 year. It’s also more flammable than the other types of generator fuels and is the least-suited for cold weather.
    • Diesel. The most commonly used fuel type is diesel. Diesel generators are among the most popular because they run more efficiently than gasoline-powered generators and the engine mechanisms are straightforward. They are the least expensive to operate and maintain. Plus, the fuel is less flammable than gas, though just as easy to acquire. Diesel fuel must be stored on-site and has a shelf life of 1.5-2 years. Fuel additives make diesel acceptable for use in cold areas. Diesel is best for applications that require more than 150 kW of power.
    • Natural Gas. One of the biggest advantages of natural as generators is that as long as you are hooked in to the local utility grid, you don’t need to store the fuel on-site. This makes natural gas generators very popular for in-town uses such as at hospitals, schools, homes, and businesses. It’s not as convenient for larger industrial applications or those where there is no access to a natural gas line. Natural gas is plentiful and works well in very cold climates. A natural gas generator will use more fuel than a diesel generator.
    • Propane. Propane has an indefinite shelf life and is a clean-burning fuel. Propane generators tend to run quieter than others, but they have a more complicated engine/fuel system. They use more fuel than diesel generators and tend not to last as long. Propane is not as common for large commercial or industrial applications. The logistics and costs of installing and storing propane tanks are prohibitive for large operations. Propane does work well with smaller gensets, however. Small propane generators can be used to power a few small applications during a power outage or to provide supplemental power for certain applications at any time.
    • Dual-Fuel. Generators that run both diesel and natural gas are available. These dual fuel options may make sense, especially if you are running the generator as a primary power source. The back-up fuel source provides additional insurance that the generator won’t break down due to lack of fuel.

    Which Fuel Is Right For You?

    To figure out which type of generator fuel is right for you, ask yourself these questions:

    • How much power do we need? If it is less than 150 kW, any type will do. If it is more than 150 kW, a diesel generator will provide the best performance.
    • What is our on-site fuel storage capacity? Do we have the room we need to have on-site storage and/or expand our existing storage capacities?
    • How will we access and use that fuel in an emergency or as a primary source of fuel?
    • What are our options for fuel delivery to our site? Can we hook into a natural gas line or will we require delivery? How close is our fuel provider to our site?
    • What are our options if there is a severe power outage? Will we be able to get/access the fuel we need to keep the generator running?

    If you’re still unsure which kind of generator you will need, start by researching local fuel providers. The kind of fuel that is readily available to your site may end up dictating what kind of generator you purchase.

    Contact Critical Power Exchange With All Of Your Generator Fuel Questions

    To learn more about generator fuels and fueling options, contact Critical Power Exchange at 1-877-315-4176 or visit us at www.criticalpower.com.


  5. 3 Environmental Factors That Can Influence Generator Output

    March 30, 2015 by rwritz
    3 Environmental Factors That Can Influence Generator Output

    You already know that routine maintenance is important for keeping your generator running healthy and producing the power you need when you need it. But did you know that there are other factors that influence a generator’s output and that they are completely out of your control?

    It’s true. Environmental conditions can have a huge impact on how a generator performs. It’s important to understand these factors so you can adapt for limitations on use.

    All generators require oxygen for combustion to take place at start-up. Any environmental factor that reduces the amount of oxygen in the air can cause start-up failure, engine overheating, or engine shut down. The three environmental factors that most affect the amount of oxygen in the air are: Altitude, Humidity, and Temperature.

    1. Altitude. Generators operate best at or near sea level where there are standard conditions of temperature and pressure (STP). Changes in the STP can cause inefficient operation or even cause the generator to stop working entirely. In most cases, serious problems don’t arise until you get to elevations that are 5000 feet above sea level or more. This is because air pressure drops the higher you get above sea level. This reduces air density, which can cause problems at start-up since generators rely on air for ignition. Higher altitudes also make it harder for the engine to keep cool. The less dense air inhibits heat dissipation, which keeps the engine hotter for longer periods of time than it was made to withstand. The result is hot or overheating engines.
    2. Humidity. Like altitude, humidity isn’t a problem until it becomes excessive. The water vapor in the air is what causes humidity. In extreme cases, that water vapor can displace oxygen, which is needed for proper ignition of the generator engine. High humidity can lead to start-up errors or failure.
    3. Temperature. High air temperatures also create low air density. This causes similar ignition problems as high humidity or elevated altitudes since air supply is reduced. Engines can fail to start up, overheat, or simply shut down.

    Contact Critical Power Supply For All Your Generator Questions

    Just because your site is in a high temperature, high humidity, or elevated altitude environment doesn’t mean you have to make do with an unreliable generator. There are ways to determine a generator’s performance under these suboptimal conditions. Contact Critical Power Exchange at 877-315-4176 to learn more about using generators in tough conditions. Visit us at www.criticalpower.com to learn more about our generator sales and service.


  6. Signs That You Have a Fuel Problem with Your Diesel Generator

    March 25, 2015 by rwritz
    Signs That You Have a Fuel Problem with Your Diesel Generator

    Businesses buy diesel generators so that they have backup power when they need it. But if the generator is rarely used or not maintained well, that backup system can fail, essentially negating your investment. In some cases this is mere inconvenience. In others, it can shut down the business or, in extreme cases, such as in a hospital environment, be life-threatening.

    To avoid these types of situations, routine generator maintenance is a must. But most generator maintenance advice focuses on things like load bank testing, parts inspection and replacement, checking fluids and battery levels, and making sure the control panel readings are accurate. Rarely does fuel quality cross our minds, yet without adequate fuel, the system won’t work. That’s why fuel management should be added to every diesel generator maintenance checklist.

    Diesel Fuel Management

    Diesel fuel is a natural substance that degenerates over time. After 6-12 months, sitting fuel should be cleaned or replaced to ensure optimum performance of your generator. Fuel that sits too long can grow bacteria and generate sludge build up, neither of which is good for your engine. It’s not always possible to anticipate when fuel will go bad since it happens so gradually and is highly dependent on storage conditions. For that reason, fuel sampling and analysis should be done on a regular basis.

    The good news is you don’t need to toss out unused fuel after 6-12 months of sitting. Diesel fuel can be cleaned. Called Fuel Polishing, the process involves a fuel analysis followed by necessary sterilization, a cleaning of particulates, bacteria, fungi, and rust. Cleaning is done using a combination of chemicals, filters, or algae-based solutions.

    Spotting Problems with Your Generator’s Fuel

    • Fuel problems can show up in both the fuel tank or in the generator itself. Common signs that you have a fuel problem include:
    • Fuel appears dark in color.
    • Fuel smells odd.
    • Sediment has formed in the tank.
    • Dark colored exhaust.
    • Clogged fuel lines and/or filters.
    • Damage to the starting system.
    • Clogged or damaged fuel injection pumps or injectors.
    • Generator performance issues.

    Add Fuel Maintenance to Your Checklist and Protect Your Generator

    To ensure an adequate power supply when you need it, you need more than a backup generator. You need a well-maintained generator and a supply of clean fuel on-site. Add fuel sampling and analysis to your generator maintenance checklist and you won’t have to worry that your power will fail when you need it most.

    To learn more about generators and generator fuel management contact Critical Power Exchange at 877-315-4176 or visit us online at www.criticalpower.com.


  7. Advantages of Air-Cooled Generators

    March 17, 2015 by mvadmin
    Advantages of Air-Cooled Generators

    Air-cooled generators are some of the most cost-effective and reliable generators on the market. These machines have a long history of use and many fans due to their plentiful benefits.

    What Is An Air-Cooled Generator?

    Generators create a lot of heat when in use and the engines must be cooled off periodically to reduce the risk of overheating or premature engine failure. Air-cooled generators rely on fans and ambient air to cool the engine. The fans force air that is drawn in from the outside over the engine to keep it cool. This is in contrast to liquid cooled generators that rely on enclosed systems and liquid anti-freeze to keep the engine at appropriate temperatures.

    Air-cooled generators are typically smaller than the liquid cooled machines, used in machines up to 22kW. Generators over 22kW are generally liquid-cooled.

    The Advantages Of Air Cooled Generators

    • Simple, Efficient Design. Fewer engine components make the air-cooled generator a much simpler design that takes up much less space than other types of generators. This simpler design affects many different aspects of the machine, which we get in to below. Diesel-fueled generators have even more efficiency benefits since they require less fuel to run than natural gas-powered units, warm-up faster, and operate at higher temperatures.
    • Reliable. Simpler designs are more reliable with fewer components that can fail. They are commonly used in critical applications and where reliable long-term power is needed. Since they are smaller generators, they are highly portable, making them perfect for emergency situations.
    • Adaptable. Since only air is needed to keep the engine cool, air-cooled generators can be used in many different environments without fear of mechanical complications. Excessive heat, cold, and dust don’t affect the cooling process. Fewer operational demands make these types of generators highly adaptable and useful in many different applications.
    • Inexpensive. Since air-cooled generators don’t need as many engine components as liquid-cooled models, they are comparatively less expensive. They also tend to be smaller generators with lower output levels, which also impacts their price. Diesel-fueled generators ultimately require less fuel than other types of generators, which can save you money too.
    • Low maintenance. Fewer components and a less complicated cooling system decrease the maintenance needs of air-cooled generators. Not only are there fewer pieces to maintain, there are fewer components to fail, reducing overall downtime.

    Right Sizing Your Generator

    Despite the many benefits of air-cooled generators, they may not be right for every application. Do your research to determine if an air-cooled machine can meet your power and usage requirements before making a purchase. For help evaluating and comparing generators contact Critical Power Exchange at 877-315-4176 or visit us online at www.criticalpower.com.


  8. Parallel Generators: Do You Need Them?

    March 13, 2015 by mvadmin
    Parallel Generators: Do You Need Them?

    Today’s need for constant electrical power is one of the primary reasons home and business owners install generators. The whole reason generators are installed is to provide uninterrupted electrical power, either as a main source of energy or for back-up purposes. If the generator were to fail for some reason, the facility would be left without power – the exact situation site managers were trying to avoid. That’s just one reason that some sites install parallel generators.

    When To Install Parallel Generators

    Besides providing backup power for your primary or backup power source, parallel generators are also used in situations where the power demands of the site cannot be met with a single generator. Available units may provide way more power than you need or much less power than you need. In either case, a parallel set can be used to meet your exact power demands without you having to purchase overcapacity or make do with less power than is needed.

    How Parallel Sets Work

    Parallel gensets aren’t difficult to understand. Instead of one generator, two or more units are installed and connected to the same critical systems or into the main power system to provide backup or continuous power. In many cases, particularly when used as a redundant source of power, two of the exact same generators are installed. This is the easiest way to set up a parallel system since output rating, alternator pitch, and other features are exactly the same.

    For organizations that need varying power levels depending on changing demands, gensets with varying output levels may be a better choice. Parallel sets with varying output levels provide greater flexibility in use, allowing you to ramp up the output when maximum power is needed or take it down during times of minimal demand. Paralleling switchgear is used to connect the sets together and into the main power system.

    Benefits Of Parallel Generators

    Today’s parallel gensets are much easier to manage than parallel sets of the past, making them more accessible for smaller business and applications. Top benefits include:

    •    Improved Reliability. Multiple generators improve the overall reliability of the power system. Even if one unit fails, the second one is standing by, ready to pick up the slack.
    •    Readily Expandable. Having more than one generator on hand makes it easy to meet your power requirements as load demand increases over time.
    •    Flexible. Multiple smaller units will fit more easily into the physical spaces available since they do not have to be located next to one another and can be distributed throughout the site, wherever space is available.
    •    Maintenance Benefits. Multiple units mean maintenance and service can be conducted at any time without fear of disrupting the entire power supply.

    Do You Need Parallel Gens?

    • Do you need an uninterrupted power supply?
    • Do you need more power than one generator can provide?
    • Are you having trouble finding one generator that meets your power demands fully?
    • Do you have limited physical space for a generator?

    If you can answer “Yes” to any one of these questions, contact Critical Power Exchange at 877-315-4176. We can help you find a genset or parallel sets that will meet your power demands without breaking your budget. Visit us online at www.criticalpower.com.


  9. Generator Maintenance Checklist

    March 10, 2015 by mvadmin
    Generator Maintenance Checklist

    Like any other piece of machinery, generators need routine maintenance, even if, or perhaps especially if, they are not used frequently. This helps ensure the machine will work properly and to its full potential when it is needed. Regular maintenance also extends the life of generators.

    Generator Maintenance Checklist

    Generator maintenance needs are extremely predictable. The machines are so widely used and have been used for so long that we can reliably predict when parts will fail or need repair. How frequently a generator needs maintenance depends on the generator. The best course of action is to follow the manufacturer’s recommended maintenance schedule.

    Most maintenance schedules will follow the same checklist. You’ll need to:

    Remove worn parts and upgrade or replace them.

    Check fluid levels, including coolant and fuel.

    Inspect and clean the battery.

    Conduct a load bank test on the generator and automatic transfer switches.

    Check that the control panel readings and indicators are accurate.

    Change the air and fuel filters.

    Inspect the cooling system.

    Lubricate parts as needed.

    In-House Maintenance Vs. Contractual Maintenance

    Now you may be wondering if you have the time or expertise to do generator maintenance in-house. You’ll be pleased to know that finding a qualified technician to perform routine maintenance on generators isn’t so hard.

    Businesses that have several gensets or use them for prime power usually have full time engineers devoted to repairs and maintenance. Smaller companies or those who use the generator infrequently usually do not have full-time staff devoted to generator maintenance. Instead, they have maintenance agreements with generator dealers or electricians to come in and perform the maintenance. Contractual maintenance agreements often have the added benefit of providing you with priority service in an emergency and even discounts on necessary work.


    Whether the technician is an employee or a contractor, the duties are the same:

    Inspect the systems

    Review technical data on the machine

    Maintain records

    Ensure safety measures are in place as recommended by the manufacturer.

    The Importance Of Maintenance Records

    One thing that is worth noting is the need for accurate maintenance records. Every time maintenance is performed, whether it is routine or emergency, the service should be logged. Logs create a paper trail of maintenance and can be used to analyze the generator’s performance over time. Along with the actions taken at each inspection or repair, the generator’s readings and parameters should be recorded along with the hour meter reading. If this data is recorded every time, the inspector will be able to notice abnormal changes in the readings, which could indicate a performance issue.

    Protect Your Power Supply With Help From Critical Power

    As with most pieces of machinery, a little preventative maintenance goes a long way. When the maintenance is tied to the power capabilities of your facility, the benefits far outweigh the costs. You can rest easy knowing your generator will work properly when you need it and that you can head off unexpected – and typically expensive – repairs.

    To learn more about generators or to find a genset for your facility contact Critical Power Exchange at 877-315-4176 or visit us online at www.criticalpower.com.


  10. Preventative Maintenance Tip: Load Bank Testing

    March 5, 2015 by mvadmin
    Preventative Maintenance Tip: Load Bank Testing

    One of the most important preventative maintenance actions for generators is regular load bank testing. Generators must be able to provide reliable power during emergency situations, but if they are only providing that power during emergencies, how do you know the generator is working properly or can handle the demands a total loss of power will place on it?

    That’s where load bank testing comes in. This test not only helps ensure the generator will actually perform when needed, it also tests the generator’s load capacity. That is, it tests the highest possible load the generator might have to handle during a power outage.

    What You Need To Know About Load Bank Testing

    Generator load bank testing requires a physical examination and assessment of the equipment. This is a basic examination to make sure everything is working properly and safely. Then, special equipment called a load bank is used to test the power generating capabilities of the generator. By placing artificial loads on the generator, it can be tested at its full kW rating and its performance can be evaluated.

    Most generators don’t ever have to operate at their full kW rating, which is why load testing is so necessary. Without the test, you have no way of knowing if the generator can handle the power demands and sustain the necessary pressure levels without overheating. Gensets that are used infrequently benefit the most from load bank tests, but every genset should undergo load bank testing annually.

    The only thing you need to conduct a load bank test is a load bank machine and time.

    What Happens During A Load Bank Test

    During a load bank test, artificial load is placed on the generator. Gradually, at timed intervals, the kW load is increased and critical engine parameters are measured. Eventually, the generator will be running at full power and full temperature. Other performance indicators that are observed include the machine’s ability to handle boost and its ability to function at the highest load possible for sustained periods of time.

    Benefits Of Load Bank Testing

    Verify generator and genset capabilities at full load.

    Can detect problems early, preventing expensive breakdowns and repairs.

    Cleans out the exhaust system, soot and carbon deposits.

    Ensures proper operation of cooling systems.

    At Critical Power Exchange, we perform load tests on every new, used, or surplus generator we sell so you know your genset will be able to provide the power you need when you need it most. Learn more about our generator sales and service by calling 877-315-4176 or completing our contact form.