It is device that converts mechanical energy into electrical energy using diesel.
It provides electrical power to facilities that are experiencing power abnormalities, including power outages. There are however a number of different methods that can be employed such as, generator paralleling, mains synchronizing, peak lopping, redundant applications, etc.
In general, yes they are. However, over the years a number of advances have been made to limit these noises quite substantially. Methods including custom bespoke canopies and / or containerization lined with acoustic suppression material are used in conjunction with advanced silencers and mufflers. In certain applications technological advanced ventilation louvers are used to limit noise escaping.
They are complex equipment simplified to be operated by a few simple buttons. In most cases generators are automated to manage the power abnormalities themselves.


Considering the units use more recent technologies, yes.
The system monitors the load and can automatically start up and take the load during the peak load demands.

There is also an alternative option to this known as Peak Lopping or Peak Shaving. This method uses the generator in parallel with mains power. The generator and mains then share the load appropriately. It is particularly handy when the generator/s cannot handle the peak load demands alone. The outcome however remains the same.

It is important to note that most utilities require pre-approval for this method.

Of course. There are a number of methods employable to achieve the appropriate ventilation. It generally referred to as remote cooling. One of the more common methods of remote cooling is to replace the radiator and fan with a compact heat plate exchanger. The radiator, or in some instances custom condenser units, are then situated remotely where the suitable cooling can be achieved.
Generators of different sizes, ages, and makes can generally all be paralleled. There are certain limitations that lie with e.g. droop kits, voltage regulators and the unit controllers. These can in most instances be overcome with changes performed by an expert.
The length a generator can operate without stop is very much dependant on the Rating:Load ratio, i.e. at what percentage is the generator operating. However, considering all these conditions are met, a generator can operate as long as it has diesel up to the next scheduled maintenance which is usually based on operating hours. This can be in excess of months.
Generators are usually rated in Standby, Prime, and Continuous. It is very important to know the difference to ensure the correct unit rating is selected when making your next purchase.

Continuous Power: This rating ensures that the generator is able to supply the load continuously until the next scheduled maintenance. As a rule of thumb, the load should be less than 70% of the generator’s Prime rating.

Prime power: This rating ensures that generator is able to carry the load for extended periods of time but with limitations. These limitations depend on the manufacturers and is generally given in hours. E.g. 500 hours. This is the most common rating used in industry.

Standby power: The standby power rating is the absolute peak power a generator can deliver for one hour every twelve hours. Accept it as the generator’s overload ability.

Very much so. Too lightly loaded and too heavily loaded will affect your set.

At loads of around 30% or less the generator will experience Wet Stacking. This is usually evident when a lot of diesel is noticed coming from the exhaust and through the filters.

Generators are most happy operating around 70% of its Prime rating.

Overloading a generator would also have its obvious consequences.

Yes, it does. As a norm generators are rated at power factor 0.8. This is in theory the average operating power factor of most loads. It is important not to get confused with mechanical and electrical powers in this instance.

For loads with power factors ranging from 0.8 to 1 there should be no concern and the generator will operate as intended. Most new age generators will be able to hand a minor leading power factors which can be obtained from its Capability Graph. It is important to note that power factors with higher leading power factors may result in the generator shutting down on frequency and / or voltage abnormalities. Speak to your generator in this instance but by connecting your resistive and inductive loads fist will help. Also, good practice is to disconnect the power factor capacitor bank prior to connected the generator to the load.

For load power factors lower than 0.8 the resultant will be higher phase currents. Alternators are limited and protected at set maximum current carrying capabilities. The end result will be the generator shutting down on overload. Speak to your expert regarding the possibilities. In principle generators for these loads will be rated higher.

For both cold and hot temperatures careful considerations will have to be taken. Increased cooling will be required in hot areas and certain alterations for very cold locations shall have to be taken.
It does. Most suppliers do not consider locations below 1000m above sea level to have a performance effect however for sites located above 1000m one would have to consider speaking to your expert. Most manufacturers have a set derating factor that they impose which effectively means the set is rated at greater power in order to deal with lower air pressures.
Generators are fairly robust to electrical loads but only up to a point. For loads such as large motors certain allowances must be considered. It is important to ensure there are some sort of start up current limitations such as soft starting and variable speed drives installed. The downside to ignoring current limitations are having to install large costly oversized generators.


A rotary UPS, also referred to as a Dynamic UPS, is a UPS (Uninterrupted Power Supply) that uses rotational kinetic energy to supply the load during power abnormalities for brief periods un such time as the prime mover (engine / generator) has started and continued by supplying the load. A RUPS also conditions the power including harmonics, power factors, voltage sags, voltage swells, voltage dips, voltage transients, and voltage spikes.

Since they don’t use sensitive power electronics they are considered electrically and environmentally robust and is ideally suited for loads with large power variations, sensitive IT equipment, large industrial motor applications where high fault current contributions and startup currents are present.

Rotary UPS’s can be employed in all areas of the electrical industry where power conditioning and protection against power interruptions are required. This ranges from sensitive IT facilities to heavy industrial production factory plants.

Even though it is common to find dynamic system applications below 400kVA, the all-round perception is to use them for larger applications of greater than ≈400kVA.

Our personal opinion is that certain UPS applications are better suited for certain applications than others and vice versa.

There is a large marketing battle continuing on efficiencies, innovation, securities, total cost of ownership, system costs, durability, robustness, life span, etc. when Statics are compared to Rotaries.

In many instances these arguments hold true and in others they are merely clever marketing statements that conveniently ignores certain factors.

The fact of the matter is most quality UPS systems of all sorts offer quality power to the load. It is best to consult your trusted professional for advice pertaining to your specific application.

  • They are ideally suited for a wide range of loads ranging from IT equipment to large industrial motor loads.
  • They have high fault current capabilities in excess of x15 rated current. Why is this important? Well, when a circuit in the network is under fault the RUPS will be able to handle the fault current allowing the circuit breaker to trip. If this UPS is unable to handle the fault current it transfers the load to bypass leaving the load unprotected and vulnerable to power abnormalities.
  • They are electrically and mechanically robust, meaning they can comfortably handle large sudden power variations and can be placed in a basic housing or facility without having to control a sensitive environment.
  • Most RUPS systems have a high operating efficiency usually ranging through a broad spectrum of operating percentages from 25% to 100%. Why is this important? Well, in the case of redundant applications (N+N) the units operate at no more than 50%. This is to ensure one unit is able to absorb the remaining 50% should the other fail. Therefore the operating efficiency at 40%-50% is the important one. UPS systems hardly ever operate at or near 100% and efficiencies at these values should never be considered. Rather focus on efficiencies at a range of 40% – 75%.

The environmental cooling costs for both operating and procurement must be included in their particular efficiency calculations.

All efficiency ratings must be while a UPS system in connected to its energy storage device and operating in online mode.

  • They perform power factor correction.
  • A RUPS, including its energy storage device, has a long life expectancy.