Frequently Asked Questions

The primary difference between kW (kilowatt) and kVA (kilovolt-ampere) is the power factor.  kW is the unit of real power and kVA is a unit of apparent power (or real power plus re-active power).  The power factor, unless it is defined and known, is, therefore, an approximate value (typically 0.8), and the kVA value will always be higher than the value for kW. 

For industrial and commercial generators, kW is most commonly used when referring to generators in the United States, and a few other countries that use 60 Hz, while the majority of the rest of the world typically uses kVA as the primary value when referencing generator sets.

To expand on it a bit more, the kW rating is essentially the resulting power output a generator can supply based on the horsepower of an engine.  kW is figured by the horsepower rating of the engine times 0.746.  For example, if you have a 500-horsepower engine it has a kW rating of 373. The kilovolt-amperes (kVA) are the generator end capacity.  Generator sets are usually shown with both ratings.  To determine the kW and kVA ratio the formula below is used.

0.8 (pf) x 625 (kVA) = 500 kW

The power factor (pf) is typically defined as the ratio between kilowatts (kW) and kilovolt amps (kVA) that is drawn from an electrical load, as was discussed in the question above in more detail.  It is determined by the generator’s connected load.  The pf on the nameplate of a generator relates the kVAto the kW rating (see formula above). Generators with higher power factors more efficiently transfer energy to the connected load, while generators with a lower power factor are not as efficient and result in increased power costs.  The standard power factor for a three-phase generator is 0.8.


What is the difference between standby, continuous, and prime power ratings?

Standby power generators are most often used in emergencies, such as during a power outage.  It is ideal for applications that have another reliable continuous power source like utility power.  Its recommended usage is most often only for the duration of a power outage and regular testing and maintenance.


Prime power ratings can be defined as having an “unlimited run time”, or essentially a generator that will be used as a primary power source and not just for standby or backup power.  A prime power-rated generator can supply power in a situation where there is no utility source, as is often the case in industrial applications like mining or oil & gas operations located in remote areas where the grid is not accessible.  


Continuous power is similar to prime power but has a base load rating.   It can supply power continuously to a constant load but cannot handle overload conditions or work as well with variable loads.  The main difference between a prime and continuous rating is that prime power Genset are set to have maximum power available at a variable load for an unlimited number of hours, and they generally include a 10% or so overload capability for short durations.

An automatic transfer switch (ATS) transfers power from a standard source, like a utility, to emergency power, such as a generator, when the standard source fails. An ATS senses the power interruption on the line and in turn signals the engine panel to start.  When the standard source is restored to normal power the ATS transfers power back to the standard source and shuts the generator down.  Automatic Transfer Switches are often used in high availability environments such as data centers, manufacturing plans, telecommunication networks, and so forth.

Petrol Generators are normally high-speed generators, this means that it runs at 3000rpm. With this it is smaller and lightweight, and easy to move around, some bigger models also have wheels. Another positive look is it is cheaper than most diesel models to buy. It is good for use as a manual generator for short periods. Maintenance is not too expensive for renowned brands. Petrol generators’ downfall is fuel consumption, especially on the larger models, also fuel storage, and it is also not too good for a petrol generator to be stored for a long period with fuel still in the carburetor, as petrol tends to gel and block the main jet. The carburetor then needs to be cleaned by professional personnel.


Diesel generators are ideal for automatic use, especially because the diesel fuel, is a fuel injection and this means that starting is not a problem for a longer period. Generators need to be started often, petrol and diesel models. Diesel-powered generators are expensive, even high-speed generators. Diesel generators are fuel-efficient. In my opinion, if you can afford it, and your requirement is power generation for long periods then diesel is the answer.

WALT portable diesel generators are designed to deliver reliable power day after day for your home. All the models are full power and continuously & stable output AC power anytime. Less maintenance than gasoline & gas types. 5kW to 16kW models for your choice.

Firstly, we advise you to calculate the power needs for your home or often use household appliances by a licensed electrician. Secondly, reserve 10% to 20% power needs. Such as if you need a 5kw generator set, the recommended 5.5kw or 6kw will be better

We are equipped with 16 liters and 30 liters capacity fuel tanks for the portable diesel generators. They can enough support the Genset continuous running 10 to 15 hours even longer

Firstly, we advise you to calculate the total power needs for your sites by a licensed electrician or engineer. Secondly, reserve 10% to 20% power capacity for increased demands in the future. Such as if you need a 100kw generator set, the recommended 110kw or 120kw will be better

It is based on your budget and actual usage. Each brand of engine has its advantages. For own house use, Fawde, Isuzu, Yangdong are good. For middle/high-end buildings, factories, power plants, data centers, Cummins, Perkins, Deutz, Baudouin will be better. Contact us to get more info

Our diesel generators meet Tier 4i (EPA), StageII, Stage IIIa, Stage V standards. E-mark certificate for the Europe market. Contact us to get more info

Generator sets can be paralleled for either redundancy or capacity requirements.  Paralleling generators allow you to electrically join them to combine their power output.   Paralleling identical generators will not be problematic but some extensive thought should go into the overall design based on the primary purpose of your system.   If you are trying to parallel unlike generators the design and installation can be more complex and you must keep in mind the effects of engine configuration, generator design, and regulator design, just to name a few.

In general, most commercial generators can be converted from 60 Hz to 50 Hz. The general rule of thumb is that 60 Hz machines run at 1800 Rpm and 50 Hz generators run at 1500 Rpm. With most generators changing the frequency will only require turning down the rpm of the engine.  In some cases, parts may have to be replaced or further modifications made.  Larger machines or machines already set at low Rpm are different and should always be evaluated on a case-by-case basis.  We prefer to have our experienced technicians look at each generator in detail to determine the feasibility and what all will be required.

Getting a generator that can handle all your power generation needs is one of the most critical aspects of the purchasing decision.  Whether you are interested in prime or standby power, if your new generator can’t meet your specific requirements then it simply won’t be doing anyone any good because it can put undue stress on the unit and even damage some of the devices connected to it.  Determining exactly what size of generator to get is please via professional electrician to give exact calculate

AMF or (Automatic Mains Failure) is Mains failure detection, Generators with AMF consist of a means of monitoring the mains and start when it detects that the Main Power has failed. It can be set up in different ways. The WALT GLOBAL POWER Range is fitted standard with an AMF Panel, manufactured by Deep Sea Electronics. This is a PLC that monitors not only the incoming power but also the generator.

Yes, sure. WALT portable diesel generator can equip with an automatic transfer switch system and automatically work between mains and the Genset when the power failure/back. Easy operation and convenient use

WALT is a manufacturer and ensures all of our products are in brand new & unused condition when they are delivered to the consignee. Usually, our production time requires 25 days after the order confirmation.

12 months global warranty provided by WALT. During this period, if the generator set meets any use questions, you can contact our local dealers (if have) or directly contact us for support

The operating modes depend on the application it needs to supply power to. Usually, Standalone mode, Standby mode, Parallel with the Mains mode. Diesel generators with different operation modes may have different system designs. Contact us to get more info.

The load on a diesel generator is the power being consumed from the unit. Such as lights, heating, AC units, fridges, chillers, fans, or other motors. The sum of all the power requirements for any application is the total load. The generator needs to be able to cope with the load needs smoothly.

Increase power and redundancy by paralleling generator sets. Also, reduce the generator set costs when you have a limited budget. More cost-effective to combine several smaller units in preference to one larger unit