Q. How large a generator do I need for my home or small business?

A. Every home or small business is different. The size of the generator is based on the type of appliances, equipment, pumps, air-conditioners, and other electrical devices requiring power. There are some power requirements that will establish a minimum size generator system: 

1) Well pumps usually require 2-3 times the run watts to start the pump. The Franklin Well Pump Company has an informative generator motor starting guide on their website  that shows how large a generator kw rating you need for each horsepower pump. The charts are typically designed for three-phase applications with a note to increase the generator size by a certain percentage for 2-wire or single-phase applications. These charts are based on providing a safety factor for the pumps to reduce any voltage drop during startup of the pump motor which can cause premature failure; 

2) Combination heat pump/air-conditioner systems are normally on 60 amp 240v (14400 watts) breakers and use 30 amps (7200 watts) for the heat cycle and the same for the air-conditioning function; 

3) Electric furnaces are typically on 50 amp 240v (12000 watt) breakers; 

4) Hot water heaters operating on 240v power normally use between 20 amps (4500 watts) and 25 amps (6000 watts) depending on the size and efficiency design; 

5) Electric kitchen stoves with oven and top burners are usually on 50 amp (12000 watts) breakers. Combination stoves with a separate top burner are on 30A breakers and the companion oven is on a 30A breaker ; and 

6) Air-conditioners come in a variety of sizes and ratings which need to be calculated based on the BTU output or stated amperage. A general rule of thumb is 4kw for every ton (24000 BTU's) of air-conditioning. Some of the newer high efficiency pumps-motors use a bit less. A 2-ton unit is rated at 24000 BTU's which normally requires 18- 20 amps (4300 - 4800 watts) to start the unit and 15 amps (3600 watts) to operate it. Another factor you must consider is the type of voltage and the impact on available amperage. Your service panel is normally rated at 200 amps @ 240v and the average home uses approximately 140 to 160 amps of 240v power to operate everything at the same time. 

Your larger appliances (well pump, kitchen stove, water heater, electric dryer, electric heater, and heat pump system) will typically use 240v power and the lights and other smaller appliances will use 120v power.  It is important to consider this difference in doing the load calculations because the important calculation is to determine just how many amps and watts you will need. For example, if you want to operate your refrigerator (20 amps x 120v = 2400 watts), freezer (20 amps x 120v = 2400 watts), electric hot water heater (20 amps x 240v = 4800 watts), washer (20 amps x 120v = 2400 watts), and electric dryer (30 amps x 240v = 7200 watts) all at the same time you will need approximately 19200 watts to meet the breaker requirements for these appliances. In reality the breakers are typically oversized for safety by 10 to 15% and the above appliances will not all operate at peak at the same time and the above load can be handled with a 15000 watt (15kw) generator set (genset).

The major appliances, pumps, or other motor driven devices that you plan to operate with your generator system need to be considered when calculating the minimum size of a generator. Sizing a generator system requires you to honestly assess your needs and wants. For a comprehensive and detailed understanding of the elements of sizing a residential or small business generator see the ADG publication ABC's of Sizing a Generator instruction booklet which also provides electrical charts, electrical formulas, and rules of thumb for sizing loads.  This informative publication is available in CD or PDF format @ $35 (which is refundable with any generator purchase).

Q. What is the advantage of buying a generator direct over the internet through ADG as opposed to buying from a local dealer?

A. ADG supplies many of the best generator products available in the world today at the most competitive prices available. Our factory direct program removes the middle man and generally saves the customer 10-20% off the normal dealer price. Another benefit is the wide selection of products and knowledge of available products that insures that you get the best available generator system for your application at the best possible price. 

The standard ADG Customer Advantage Program gives you protections that make it easier to own a generator system: 

1) SALES ENGINEERING SERVICE - competent and knowledgeable sales engineers to discuss all your requirements and application and to properly help you size and calculate all motor starting requirements; 

2) CUSTOMER-FIRST -  single source contact for all parts and warranty assistance on all ADG products; 

3) DESTINATION SHIPPING - for trouble-free shipping in the USA we ship FOB destination so we take care of any cargo claims for you; 

4) EASY-START - guide and photos for generator electrical connections and controller operation ; and 

5) AFTER-SALE SUPPORT- free lifetime technical trouble-shooting service via phone, fax, or e-mail. We do our best to honor our commitment to providing you with the BEST PRODUCTS, BEST PRICES, and BEST SERVICE.

Q. There are a lot of Asian manufactured generators advertised on ebay and marketed through various low-cost discounters that seem to be a great bargain - are they?

A. ADG advises caution when it comes to the low priced imports from Asia. In recent years there has been a flood of Asian manufactured gasoline and diesel portable generators using look-alike Honda-type gasoline and Yanmar-type diesel engines packaged in a wide variety of product designs. These units are typically considerably less expensive than the real Honda gasoline generators and the real Yanmar, Hatz, or Kubota diesel engine powered generator systems like the ones ADG offers for sale. The old adage of "you get what you pay for" has never been more true than when dealing with these imported Asian generator systems. While the initial cost is low and the products are attractively packaged there are some things you should consider before you purchase one:

1) While the engine on some models tend to run ok and under light operating conditions last awhile, they tend not to do so well in high heat or heavy use environments.

2) The generator ends tend to be more problematic than the engines. Our experience has been they do not hold up for high use applications especially in hot weather.

3. There is very little support for these units and most generator and engine repair centers will not even consider working on them. Other than the company who sold you the portable gasoline or diesel generator or generator-welder you will fine few repair centers that will give you the time of day. 

4. We base our observations on our own experience and related problems and the many calls we receive from frustrated customers who saved a buck but paid a price. One fellow called us from the Bahamas, who had operated a 6kw diesel import for a total of 4-hours before it failed and wanted to know if parts were available, he concluded that he had thrown away $1800 thinking he had gotten a bargain. 

5. There are some importers who advertise these low cost Asian engines and generator systems with Mercedes or Mann type engine designs indicating they are industrial grade and advanced designs. In truth many of these engine or generator products are 1930's vintage designs and great if you love to spend all your time working on them. There is absolutely no comparison in quality or performance between these low cost engine or generator products and the modern Japanese or European products. Again, you get what you pay for and saving a few bucks on a cheap engine or generator system will likely cost you money.  If your application is for occasional real light use in a cooler climate you may have some success using the cheap imports. Again, you normally get what you pay for and the other old adage, "if it appears to be to good to be true, it most likely is", is so true in the purchase of these cheap imports.

Q. Are any of the Chinese generator imports considered high quality?

A. Yes. Some of the more industrial quality Cummins, Deutz, and John Deere diesel generator systems seem to be of much higher quality design and feature better components. A majority of these products are designed for 3rd world and non-EPA regulated countries. Are these products of the same quality as the made in USA and European imports? It is too early to know. As for service and parts support, that most likely is another issue and related to the importer of the product in each geographical area or country.  

Q. Is a 3-phase generator suitable for the average homeowner or small business?
A. A majority of generator packagers typically will use an over-sized 12-wire 3-phase 3-pole generator end for single-phase applications and utilize 2-poles for single-phase. This requires that the generator end is sized approximately 1/3rd larger than the rated single-phase output. This approach of using a 12-lead over-sized 3-phase generator system allows the generator system to be used for both single-phase and 3-phase applications depending on customer requirements. (Example: 10kw engine coupled to a 15kw generator end). There are a number of major brand products that are packaged with dedicated 4-lead single-phase only generators. For the most part these are quality products designed for a specific application. A note of caution: Generator packagers who assemble a 10kw engine & 10kw 3-phase generator and utilize this configuration for single-phase applications are selling you a potentially problematic generator configuration because the engine will always be oversized for the single-phase output capability and running light loads will make the engine susceptible to "wet stacking".  

ADG uses a wide variety of the leading generator ends for both our single-phase and 3-phase applications (Newage/UK & USA, Somers/France, Mecc Alte/Italy, and Marathon/USA). The advantage of using an over-sized generator in a 3-phase or single-phase application is to meet motor starting requirements without having to use an overly large diesel engine because of potential problems with "wet stacking". If your generator system will power air-conditioning units, pumps, heat pumps, well pumps, welders, or irrigation pumps you need to have the system calculated by one of our sales engineers to make sure of the proper design and size. ADG provides this service free. ADG pre-sets the proper voltage configuration and performs a load test on all of our gensets at the factory before shipment.

Q. What is the function of the electronic controller on a genset?
A. Most of the engine/generator controllers used today are digital and are designed to provide control of the engine and generator safeties and any autostart function for automatic transfer switch or inverter applications. The controller system, simply described, establishes the bench mark or threshold for safety shutdowns and monitors the operation of the engine and generator functions. The sophistication of a controller is based on the size of the generator and the application. Modern digital controllers for residential or small business applications are typically a simplified LED indicator for any shutdowns and a start-stop button or autostart function and is sufficient for safe effective operation of most gensets. 

In the autostart mode the controller can be used to interface with an automatic transfer switch or inverter/battery system as a standby/emergency genset. A more advanced controller provides real time monitoring of volts, hertz, and amperage in addition to the basic engine/generator safeties and autostart functions. Complex controllers typically installed on larger generator systems provide engine safeties and shutdowns for low oil pressure, high temperature, engine start over-crank, over/under-speed (hertz), low coolant level, low fuel level, KVA output, KW output, power factor (PF), engine & generator gauges in real time, and often have a communication capability for remote monitoring and starting. ADG uses a number of different digital controllers on our gensets depending on the application and customer requirements. All of our generator controllers are off-the-shelf, state-of-the-art design, for long life service and availability. We provide a single-source contact for parts for all of our products now and in the future.

Q. What kind of generator should I purchase - gaseous or diesel?

A. There are a number of factors to consider in evaluating the differences between a gaseous (natural gas or propane) powered engine: 

Gaseous powered engines can be summarized as follows for Positive Factors: 

1) Quieter engine noise level; 

2) More emission compliant; 

3) More convenient fuel source (natural gas); 

4) Gaseous engines do not have a problem with "wet stacking like diesels; less expensive units with air-cooled engines are budget priced. 

There are also some negative LP and NG factors to consider: 

1) More expensive to operate by as much as 3-times the fuel consumption compared to diesels; 

2) Shorter life expectancy by a factor or 10 to 1for air-cooled models and 3 to 1 for water-cooled models compared to diesel powered gensets; 

3) More expensive to purchase for models over 30kw: 

4) Smaller air-cooled gaseous engines are less expensive than comparable diesels but have a short life expectancy as low as 500-hours depending on engine make and use; 

5) Natural gas (NG) begins to derate at +20 degrees above zero and propane begins to derate around -20 degrees above zero; 

6) Hurricanes and earthquakes can disrupt the flow of natural gas lines with up-rooted trees; and

7) Both NG and propane can become very dangerous if lines are broken.

Diesel engines have a number of Positive Factors: 

1) Engine life for liquid-cooled 1800rpm engines can approach 20,000 hours if properly serviced depending on the application and environment compared to 5-6000 hours on industrial quality gaseous gensets; 

2) Even 3600rpm diesel engines normally have a 10,000 to 15000 hour life expectancy with proper maintenance and service under most conditions; 

3) Diesel engines are less expensive to operate. The general rule of thumb for fuel consumption is 7% of the rated generator output (Example: 20kw x 7% = 1.4 gallon per hour at full load). Diesel generators are designed for off-road applications and can operate on dyed or farm/construction diesel fuel which is sold without the road tax and thus is considerably cheaper to purchase;

4) Diesel engines are designed to work under a load for long periods of time and perform better when worked rather than operated under light loads;

5) Diesel engines can operate in sub-artic conditions with fuel additive; 

6) Diesel engines and fuel are safer to operate because of the high flash point of diesel fuel - it is even difficult to start a fire with diesel fuel; 

7) Diesel fuel is easier to obtain during a disaster because it is a necessary fuel for the military, trucking industry, and farming operations; 

8) Diesel gensets are competitively priced for a comparative sized water-cooled gaseous models with the same features;  and 

9) The cost of owning a diesel generator system where usage is high is much lower over the long run than gaseous gensets. 

Negative Factors to consider with diesel engines: 

1) Engine noise is usually higher on a diesel compared to a gaseous engine. The use of a properly designed enclosure and sound attenuation system is more critical on a diesel engine system; 

2) A diesel engine is subject to "wet stacking" or over fueling if run for long periods of time with ultra light loads (less than 40% of the rated output). "Wet Stacking" causes the engine to smoke and run rough because the injectors become carbonized. Running a heavy load will usually clean up the over-fuel condition and allow the engine to perform properly. Diesel engines operate better and more fuel efficient when loaded (70-80% of the rated output is optimum). 

3) In sensitive emission areas in some states diesel engines are prohibited from operating over a prescribed number of hours per year to help reduce pollution levels; 

4) Diesel engines require clean moisture free fuel and a bit more maintenance than a comparable gaseous unit; 

5) Diesel fuel storage must be considered relative to required run time in your geographical area. If you live in hurricane country you might need a large fuel tank due to the high possibility of extended power outages. Some cities and counties require the generator on-board fuel tanks to be double-wall containment type which can increase the cost of the generator system; 

6) Diesel gensets are typically heavier and require more planning to load and unload than a lightweight gaseous genset; and 

7) a quality diesel genset can cost considerably more than an inexpensive air-cooled gaseous light duty standby genset of the same size.

ADG recommends the use of liquid-cooled diesel engine gensets in hurricane environments where the potential for long run times is high or for prime duty applications where the generator is the prime source of power. ADG carries a number of high quality diesel powered generator products in sizes 2kw to 2000kw designed to provide years of trouble-free operation.

Q. Do 3600rpm diesel generators last as long as 1800rpm gensets?

A. Generally the 1800rpm engine speed will last longer, use less fuel, and are slightly quieter than the 3600rpm units. Most small diesel portable generators in the 3 to 6kw class are air-cooled 3600rpm engines designed to keep the weight and cost down. ADG has designed a 3600rpm air-oil cooled Kubota diesel powered portable for severe duty applications that has an expected engine life of up to 10,000 hours. This unit has been engineered to provide reliable power for construction, military, rental industry, and government applications. 

Kubota has developed the GL7000 / 7kw and GL11000 / 10kw series quiet enclosed contractor/residential rated gensets using liquid-cooled 3600rpm engines to keep the weight and price affordable with great success. These engines are designed for long-life performance up to 10,000+ hours depending on environment, use, application, and maintenance. ADG has units operating in some of the most severe environments in the world with good results and longevity.

Q. We want the power generator to supply power to a computer system in our home or business - will we need a special generator design?

A. Most generators sold by ADG are designed to power computers. Some of the portable generators with capacitor regulation (voltage control from 5% to 10%) can present a problem for some computer systems if the computer is plugged directly into the electrical circuit and does not use a battery regulated power supply. The majority of 1800rpm and 3600rpm liquid-cooled generators use automatic voltage regulated (AVR-Electronic module) generator systems that provide from 1% to 2% voltage regulation. Another factor that impacts computers is the speed (hertz) control which is normally 3-5% with an mechanical engine governor regulation and .25% to .5% regulation with an electronic engine governor system. The mechanical governed systems are normally quite sufficient to provide clean power for normal electronics like computers, stereo systems, etc.

For computer service centers and other communication applications like radio stations and relay centers even if they use a UPS system the use of an electronic governor on the diesel engine is recommended. Electronic governors not only maintain engine speed more accurately but with a much quicker response time to no-load to load conditions which helps prevent voltage drop. Most industrial diesel engines equipped with autostart can be equipped from the factory with an electronic governor depending on the manufacture and engine design. ADG has developed a new line of Isuzu and Kubota diesel powered quiet enclosed and open gensets rated for both standby (emergency service less than 500 hours per year) or prime (main power source and over 500 hours per year) that can be equipped with an electronic governor. 

Q. What does the term "Wet Stacking" mean in a diesel engine?

A. Diesel engines are designed to operate with a load. When a diesel engine operates considerably below the rated output level the engine can start to over-fuel or "Wet Stack". Diesel engines perform most efficiently in the 70-80% range of rated output. When an engine operates for a prolonged period of time below 40% of the rated output it begins to over-fuel. This occurs because the injection tips began to carbonize and disrupt the fuel spray pattern. In commercial generator standby/emergency systems where loads can vary and low output conditions can occur more frequently because of the diverse load applications, an automatic load bank is sometimes used. A load bank will place a "false" load on the generator system to keep the diesel engine properly loaded to prevent a "Wet Stack" condition. 

In residential or small business applications a "false" anti-wet stack load condition can be accomplished with the use of an electric heater or other high load appliance to make sure the diesel engine generator system is not allowed to operate for prolonged periods of time below an acceptable level. Once a diesel engine begins to "wet stack" the only way to correct the problem is to load the engine for a couple of hours to burn off the excess fuel and clean up the engine. Some diesel engines are less prone to "wet stacking" than others. Generally, electronically controlled engines and engines with advanced emission systems are less likely to "wet stack". Unfortunately, all diesel engines will "wet stack" if operated for long periods of time considerably below the rated output level. It is for this reason that proper sizing and design is important. ADG can help you with all your sizing and design considerations. It is part of our Sales Engineering Service program and it is free.

Q. What kind of maintenance will my diesel generator need and how complicated is it for the average homeowner or small business?

A. Diesel engines require routine maintenance for long-life service. The normal maintenance requirements are about the same as owning a diesel powered vehicle - oil, oil filter, air filter, and fuel filter. In tropical and cold climates it is advisable to have a water-fuel separation filter system installed. Water or moisture in diesel fuel can be damaging to a diesel engine because the water properties create advanced ignition and accelerated detonation.

The engine will need an oil change every 100 to 250 hours depending on the dust conditions where you live. We recommend you change the oil filter every time you change the oil. The filters are normally the screw on type. Air filters need to be changed as required depending on how much dust is in the air. Diesels need a lot of clean air to operate properly and will suction collapse an air filter if it is allowed to get too dirty. We recommend you check the air filter every 100 hours and every 50 hours in dusty environments. Fuel filters are normally changed every 200 to 250 hours depending on how clean the fuel and dust conditions. Every diesel engine has a recommended service schedule. Like a diesel powered vehicle regular scheduled service is the key to long-life and performance.

Normally, the generator end (AC alternator) will not require any service unless you live in a dusty environment. In dusty environments we recommend you use a high pressure (50psi) air hose and occasionally blow out the dust from the generator system. Dirt and heavy dust particles can cause shorts in the internal wiring coatings under the right conditions. High heat and dust are the enemy of power generator ends.

Q. Will the genset I purchase from ADG  have adequate operating instructions and service manuals?

A. Every genset sold by ADG comes complete with an operators manual for the engine, generator, and controller if applicable. We include any special instructions for any of our added options or features (e.g. ADG remote fuel system connection & switch). In addition, most of the manufactures offer factory service and parts manual kits as an option. ADG, as part of our Customer Advantage Program supplies each generator system with an Easy-Start Guide with photos for wiring connections, other starting info where applicable, and lifetime technical trouble-shooting support via phone, fax, or e-mail to make it easier for customers to own an ADG supplied genset. Our goal is to make owning an ADG supplied generator system a trouble-free experience.

Q. How do transfer switches work and can I install one myself?

A. ADG recommends that transfer switches be installed by a licensed electrician for safety reasons. A transfer switch should be considered an "either or switch" that allows power to be supplied to the service panel either from the the utility or the generator system. There are basically four types of transfer switches to consider: 

1) Manually operated Meter connected switches designed to allow for a low cost and simple and inexpensive installation for generators supplying 7500watts or less; 

2) Manually operated Pre-select panels providing 6 to 10 pre-selected circuits that can be used during any generator supplied power situation; 

3) Manually operated Service rated (e.g. 100A, 200A, or 400A) NEMA-1(indoor rated) or NEMA-3R (outdoor rated) UL rated panels for either single or 3-phase applications; and 

4) Automatic operated Service rated panels.

If you are using a small portable generator system and have light power requirements for lights, refrigerator, microwave, etc., the use of the Meter connecting transfer switches can be very cost effective and simple to use and install. You will need to check with your utility company to make sure they allow the use of this type of transfer switch and the approved installation procedure. ADG can supply this type of residential transfer switch should you require one.

The use of a manually operated Pre-select type of panel is also suitable for use with smaller generators. Many of these type of transfer switch will only allow 120v applications. Check specifications to make sure this type of panel will meet your power requirements. ADG can supply this type of transfer switch in both single-phase and 3-phase models.

Service rated manually operated transfer switches allow you to match the size of the service panel (even if the generator is rated lower than the service panel) so you can power any circuit in the panel subject to the limits of the generator output (a 10kw generator is rated for 42Amps @ 240v single-phase and the normal service panel today is rated for 200Amps). This allows you to provide power to any breaker in the panel even though you may not be able to use them all at the same time based on your generator size and what you want to power. These panels normally require an electrician to install.

This is the normal sequence of events when the power from the utility goes off: 

1) Manually switch the handle on the transfer switch to the generator position; 

2) Start the generator and allow it to properly warm up with the generator breaker in the off position; 

3) Once the generator engine is warmed up to operating temperature engage the main generator breaker to feed power to the service panel. 

When the power returns from the utility the sequence of events is reversed: 

1) Flip off the main breaker on the generator so there is no power to the service panel; 

2) Flip the manual transfer switch back to the utility feed position; and 

3) After the generator engine has run with no-load and cooled down for approximately 5-minutes shut the generator engine down.

An automatic transfer switch (ATS) or inverter system with autostart function is designed to work with the generator autostart system which is usually a part of the generator controller system. The ATS panel is normally sized to match the service entrance panel amperage size or a special emergency panel (E-panel) created to operate special circuits that are needed during any power outage. The ATS operates with digital logic and a motorized breaker system. To activate the ATS system a two-wire open or closed low-voltage contact system is used and connected to the autostart function on the generator controller. 

The sequence of events is much that same as the manual transfer switch but done automatically so the generator starts and stops based on utility or battery power supply: 

1) Utility power goes off or batteries are low and need a charge; 

2) contacts in ATS panel either open or close (optional) creating an open or closed circuit in the generator controller; 

3) The generator controller circuitry starts the generator for a brief warm up (programmable); 

4) If the power stays off for a programmed period of time (usually2-minutes) then the ATS panel switches the power requirement to the generator side of the transfer switch and the generator becomes the power supplier; 

5) Once the ATS panel senses that the power has been restored from the utility it switches the breaker back to the utility supply side and disconnects the generator from the circuit; 

6) Normally, the ATS panel is programmed to disconnect the generator but let it continue to operate for approximately 5-minutes to cool down or to be ready to return in the event the power from the utility starts and then fails again; 

7) Finally, the generator is shutdown when the open or closed contacts return to the original position before the power outage.

One advantage of using an automatic transfer switch in 3-phase applications is the in-phase monitoring system that prevents power transfers when the transfer will damage an out-of-phase electric motor. Another benefit is the automatic exerciser function that regularly starts and runs the generator to make sure it is operating properly and to provide a regular lubrication and system check to assure the unit is run-ready when it is needed - when the power from the utility fails or the inverter system senses the batteries are low and need a charge.

Q. How are warranties handled by ADG?

A. ADG tries to sell the highest quality products available and we use only the best off-the-shelf components in our own gensets to minimize any potential warranty problems. ADG provides our customers with the factory warranty and terms & conditions on products we distribute. On ADG private label or manufactured products we provide you with a 1-year warranty on the product components. The engine & generator warranty period is based on the manufactures warranty and terms and conditions which may be longer. We also provide you with a single-source contact for any parts or warranty requirement.

Normally, it is the customers responsibility to get the product back to the manufacturers warranty station or factory for any warranty support. ADG will try and make arrangements for any warranty to be performed by any competent generator or engine repair facility near the customers residence or business. The quality of most generator products today is very high. The occasional problem can usually be resolved with a little trouble shooting and minor repair and this can often be done over the phone. ADG provides free product lifetime technical trouble-shooting service to the original purchaser via phone, fax, or e-mail.

Q. What is the difference between standby/emergency use and prime or prime continuous duty applications?

A. A majority of generator products are rated for standby or emergency use. This designation is for generators that will be used less than 500 hours per year and typically for short periods of time when the utility power fails. The prime duty rating is for use when the number of hours per year will exceed 500 and the use is on a regular basis. Prime continuous duty is the rating given for generators that are used 24-hour per day and 7-days per week. These ratings are based on the fact that the generator system will perform at the highest standby rating but when the hours or use exceed the recommended standard for standby the life expectancy can be shortened considerably and the potential for premature failure is increased. It is for this reason that the proper assessment of the application should be declared at the time of purchase. Buying a genset rated for standby duty and using it for prime or prime continuous application is penny wise and pound foolish and will normally void your warranty and cause you premature generator failure. Your generator system should be a long-term investment if properly sized and designed for your application.

Q. Why do well pumps, air-conditioners, welders, and other electrical motor driven appliances require special consideration when sizing a generator?    

A. In general, appliances with electric motors have a much higher start up amperage (LRA) requirement than operating amperage (FLA). A general rule of thumb is a minimum of at least twice the amperage to start a device as to run it. However, some devices can require up to 6 or 7 times the amperage to start as to run. It is for this reason that any residence or business with water wells, large air-conditioners, sump-pumps, or other heavy duty motor applications should consult with a knowledgeable source when sizing a generator system. ADG can assist you with all of your motor starting calculations and we can supply you with generator systems designed to provide the best performance and size for heavy duty motor starting applications.

Q. How are decibel levels calculated on generators?

A. Most generator builders calculate dBA levels at full load operation. This is the honest way to report the noise level. The USA standard is based on the sound level at 21feet and the European standard is based on the sound level at 23 feet. The calculation of dBA levels involves a complicated mathematical formula which is not the subject of this information. The relative noise level is the best way to understand the relationship of one sound to another. Generator sound levels can best be compared for small to medium generator systems (7kw - 60kw) as it relates to human conversation while a diesel genset is operating at full load:

*Entertainment Industry Quiet / Special and expensive sound attenuated and designed gensets50 to 55 dBA - barely hear the unit operate at 3-feet / normal conversation next to genset 

*Ultra Quiet / special sound attenuation design for rental fleets or residential applications
56 to 60 dBA - barely hear the unit operate at 10-feet / normal conversation at 10-feet

*Super Quiet / special sound attenuation enclosure normally with air-scoops and dense foam
61 to 63 dBA - normal conversation at 10-feet / quiet operation at 21-feet

*Residential Quiet / well designed enclosure with air-scoops and foam  
64 to 68 dBA - quiet but noticeable at 10-feet / normal conversation at 21-feet

*Industrial Quiet / well designed enclosure with air-scoop and dense foam
69 to 75 dBA - noticeable noise level at 10-feet / loud conversation at 21-feet

For the average residential application dBA levels in the 64 to 68 range are acceptable to most neighbors and meet most noise level restrictions if any exist. Some engines tend to be noisier than other engines and will have some effect on the overall dBA rating of the unit. Obviously, a 10kw generator is typically quieter than a 40kw if all other conditions are equal. The abatement of noise in diesel gensets is normally a function of the enclosure design, air-flow, and the quality and type of insulation used. Front air-scoops are typically used to remove radiator sound. Special residential grade muffler systems are used to help reduce the engine noise. ADG can supply you with all of the quiet type generator systems listed above. For special residential applications where covenants or city codes require Ultra quiet sound levels ADG has developed special acoustically engineered enclosures to meet these requirements. The ADG, Kohler, Lister-Petter, and SDMO residential and small business gensets are rated for Residential Quiet applications.

For industrial super quiet applications, such as those required for the movie industry, ADG can supply special ultra quiet generators designed to operate in the 50-56dBA range in both switchable stationary or mobile design or stationary for industrial and residential high end applications where sound regulations or zone covenants place restrictions on sound levels.  

Q. What are the most important things to consider when purchasing a standby/emergency generator system?

A. This is the most frequently asked question. Our answer is several-fold: 

1) A generator is a major purchase and should be amortized over it's expected life depending on the use and environment where it will be used. For most residential applications a quality generator will last a life time if used for standby/emergency backup. For this reason we recommend the purchase of a quality genset with suitable features for your application. A cheap or bargin price is sometimes an expensive lesson; 

2) If your backup requirements are very occasional and you only need limited power during an outage an inexpensive generator system will most likely meet your needs (air-cooled gaseous gensets); 

3) If you live anywhere on the East Coast, Florida, or in the Caribbean you are likely to need a heavy duty diesel genset and one with high quality features. Most modern diesel engines are reliable and fuel efficient. Glow plug models provide easy starting in cold weather. An 1800 rpm model will provide better fuel efficiency and longer life but cost more; 

4) The generator end is the usually the first item to fail with heavy use. The insulation coatings on the windings are based on heat ratings and 'F' is good and 'H' is better. Some major brands manufacture their own generator ends and parts, and repair is usually only available through the manufacturer. ADG uses off-the-shelf industrial brands like Marathon, Mecc Alte, Newage, and Somers because parts are readily available and any qualified service repair center can service the generator end; 

5) Controllers are a vital part of most generator systems. The controller monitors the generator engine speed for hertz, the oil pressure and water temperature, and other engine and generator functions. It shuts down the engine if one of the threshold settings for these controls fails. It also provides the autostart function for the automatic transfer switch or inverter if one is used. ADG uses off-the-shelf name brand controllers on our products to make sure they are available if one should fail; 

6) A generator is a mechanical and electrical device that over time will need some service or parts. Make sure you are purchasing a generator system that will be supported in the future from a company that will be there to support you; and finally,

7) know what you intend to operate with your generator and make sure the generator you purchase will handle your load. ADG can help you with design considerations, load calculations, and motor starting considerations. In our opinion, these are the most important things you need to consider when purchasing a generator. 

Call and talk to one of our sales engineers for a generator consultation and assistance for sizing and motor starting application. We are here to help: 208-667-4036 / 877-530-7171 toll free message call back.