kVA Power Rating

kVA Power Rating
Power ratings are expressed in different forms such as WATTS and KILOWATTS, AMPERES or AMPS, VOLTS, and also in KVA, But what exactly is kVA…

Outside the diesel generator industry, the term Kilo-volt-amperes (kVA) is not well known. A Kilowatt (kW) is a much more common a term and is how electrical items in your home are rated, you may even notice it quantified on your electricity bill so it is much more relatable but what is kVA?

Actual Power
Therefore we can refer to kW as actual power, it is the amount of power that is converted into an output.

Apparent Power
On the other hand, kVA is a measure of apparent power: it describes the total amount of power being used by a system, for example in a 100% efficient system kW would equal kVA exactly. However in reality electrical systems are not 100% efficient and so not all of the systems apparent power is being used for useful work output. Fundamentally one kVA is equal to 1,000-volt-amps. Whereas a volt is for measurement of electrical pressure an amp is a way of the electrical current measurement. A term called apparent power (the absolute value of complex power, S) is equal to the product of the volts and amps.

Power Factor
Diesel Generators have a power factor of 0.8. When you know this it is easy to convert kVA to kW because you know the efficiency level of the electrical system in question. Electrical efficiency is usually expressed as a power factor in between 0 & 1, therefore the closer the power factor is to 1, then the more efficiently the kVA is being converted into actual kilowatts.

The kW to kVA Formula:
Apparent power (kVA) x power factor (pf) = actual power (kW)
e.g. 100 kVA x 0.8 = 80 kW
The formula for converting kW into kVA is:
Actual power (kW) / power factor (pf) = apparent power (kVA)
1 ton = 200 BTU/minute
1 ton = 12,000 BTU/hour
1 ton = 3.517 kilowatts

44kva-55kva-66kv diesel-generator

Planning a Large Generator Project

Planning a Large Generator Project
Why Buy a Diesel Generator?
We are frequently faced with large scale generator projects. Whether this is a multi-megawatt diesel generator project, or a multi-site, high volume contract, we have the experience and expertise to deliver your large generator project, to your specification, on time, and on budget.

6 Factors to Consider for Your Generator Project
When it comes to enquiring about a large project involving one or more power generators, there are 6 main factors to consider while in the planning stage:

1. The Generator(s)
First of all, what kVA or kW output do you require? If you need help converting values then why not try our kW to kVA Conversion Tool. We offer canopied silent generators ranging from 7 kVA up to 550 kVA and larger open generators all the way up to 3000 kVA. Having a preferred brand or model of a generator in mind will also help speed up the process, however, if you only know of the power output required then our expert sales team is on hand to recommend the perfect generator set to suit your every need. If you require a single-phase power supply, we can also provide services to convert any of our three-phase generators (within reason!) down to a single-phase to suit your needs.

2. The Enclosure
If you are looking for one of our silent canopied generators smaller than 550 kVA then this aspect may not apply to your project. However, if you require a larger open-frame generator then this is an important factor.

The first detail to consider would be the type of enclosure you require, such as a containerized solution (20ft, 30ft, or 40ft), or whether your project would warrant a completely custom-designed enclosure, built to your exact space requirement. However, the option between enclosure types may not be a free choice depending on the size of the diesel Genset selected, and the next factor: noise level.

Given that the average noise level of an open diesel generator set is approximately 105 dBA at 1m (that’s 5 dBA louder than a train passing just 1 meter away), your generator will need its sound attenuating in order to be used in a commercial or residential setting. The average Genset installed in an ADVANCED built acoustic container or enclosure will only produce 70 to 75 dBA (at 1 meter), and the quietest enclosure we have produced was all the way down at just 55 dBA (at 1 meter). That’s quieter than a normal conversation.

As briefly mentioned earlier, if you require a specialist low noise level for your big generator project, then you may have to opt for a larger sized container or even a bespoke built enclosure in order to attenuate the sound of the generator appropriately.

3. The Fuel Supply
Another significant factor in planning your large diesel generator project is the fuel tank(s).

For smaller, canopied silent generators we offer additional free-standing fuel tanks to extend your running time capacity. Additionally, we also offer custom-built extended base fuel tanks, which provide a more space-efficient solution for increasing the standard fuel tank capacity.

For larger diesel generator projects that are containerized or feature bespoke built enclosures, we can custom build free-standing bulk fuel tanks that can be situated either inside or outside of the enclosure. Another option for bulk fuel storage is the addition of a high-capacity belly tank. These tanks can store much more fuel than free-standing solutions and are also very space-efficient as they sit directly underneath the container or enclosure. To build such tanks for your generator project, we would simply need to know the capacity you require in liters or the running time that you wish to achieve from the generator, on a single fill of fuel. Our highly-experienced 3D design team will then be able to use the latest software to model the perfect solution to suit your needs.

4. Louvres
All generators require sufficient airflow in order to function as expected. As a result, louvers will be required to provide your power systems with the necessary fresh airflow. That main types of standard louvers for containerized and custom-built enclosure generator projects that we offer are:

Standard Weather Louvres
Motorised / Gravity Louvres
Acoustic Louvres
We can also offer more purpose-built styles and options of louvers, such as fire-resistant, gas-tight, etc. If you are unsure what the best solution for your large generator would be, then get in touch with our sales team who will be able to advise which type(s) of louvers would be best suited to you.

5. Synchronising
If you don’t plan to do any type of synchronizing with your diesel generator special build project, then this step can be skipped over.

However, many large generator projects (such as data centers) feature multiple diesel-fueled generator sets that work together in parallel to provide a larger overall electric power output. This would be classed as set-to-set synchronizing.

Alternatively, your project may require set-to-mains synchronization so that you can have a seamless transfer (sometimes known as no break return) on your transition from generator power back to the mains supply. This functionality requires specialist control panels to achieve. Therefore, if you do plan on performing any synchronizing with your generator, the extra additional costs and complications should be planned for.

6. Additional Features
Now that we’ve covered the generator, enclosure, and functionality, any other additional features for either the generator or the enclosure should be accounted for. These may include:

The circuit breaker – will it be seat-mounted or elsewhere?
Cable entry – will cable access the generator via a gland plate or link box?
Painting the enclosure – do you have a paint specification in mind? Such as standard, marine, or any other spec
An ATS panel or control panel upgrade for the generator itself
Bespoke fuel transfer systems
The exhaust system
Alarms – fire alarms, smoke alarms, intruder alarms, or other alarms.
Any other additional electrical components – such as internal or external lights, or any other components you may wish to add to your project.
When it comes to planning a large diesel generator project, this article is just a starting point. However, with the 6 factors above planned and accounted for, our expert sales team will be able to work with you to provide a cost-effective solution for your power requirements. To speak with us regarding your project, or to discuss any of the elements listed above, send us an email at the [email protected] or give us a call on +880 401241354


Difference Between Online UPS and Offline UPS – Which One is Better?

Difference Between Online UPS and Offline UPS – Which One is Better?

Main Difference between Online UPS and Offline UPS – Which One to Use?

UPS, Uninterruptible Power Supply is a device that supplies power in case of power failures. A UPS can be either Online UPS or Offline UPS. Both types of UPS can be used as a backup power source but there are many differences between them.


The major point that differentiates between the online UPS and offline UPS is that the online UPS supplies power from the AC mains to the Load through the rectifier and inverter combination while the Offline UPS directly supplies power from AC mains to the load.
Before going to the list of differences between Online UPS and Offline UPS, let’s discuss the basics of Online UPS and Offline UPS.

What is UPS (Uninterruptible Power Supply)?
UPS is an abbreviation for Uninterruptible Power Supply and the reason for its name is that it provides a constant supply of power without any interruption. In Normal operation, it draws current from the AC mains, and during a power outage; it draws current from its backup source.

A UPS system utilizes a DC power stored in the battery as its backup source. The UPS charges the battery from the AC mains through a Rectifier and charge controller circuit. At the same time, it supplies power to the output AC load. In case of power failure, the UPS utilizes this charged DC power in the battery and converts it into AC using an inverter and supplies it to the AC load.

Now the switch over between the sources (AC mains and the battery in case of power failure) is instantaneous. But it does take some time. This time delay during the switching may affect some sensitive electronic equipment while other devices may tolerate it in a specific range. This is where Online UPS and Offline UPS comes into play.

What is Online UPS?
Online UPS is a type of UPS that supplies power to the AC load through the Rectifier and Inverter Combo in normal operation and uses an inverter to supply AC power during a power failure. Therefore, the output power supply always stays ON and there is no need for switching. Hence, there is no time delay in switching between its sources. There is no interruption in the case of power failure even for a nanosecond.

During normal operation, it converts the AC supply from the AC mains into DC using a rectifier and charges the battery using a charge controller circuit. Now at the same time, the DC power from the charged battery is being converted into AC using an inverter to supply it to the output AC load.

In case of power failure, the UPS will stop drawing current from the AC mains and stops charging the battery. But the AC load will continuously draw current from the battery through Inverter.

Therefore, Online UPS has a zero time delay when switching its power source. It is also why it is known as Online UPS because it stays ON even during its normal operation.

Since the current drawn by the AC load is continuously flowing through its whole circuit, the temperature of the system increases. Therefore, it needs comparatively larger heat sinks and the components that can withstand high temperature and it can tolerate current flow for a very long duration. Due to such a requirement, the cost of Online UPS increases significantly.

It continuously draws current from the battery which quickly reduces the lifetime of the battery compared to offline UPS. They are more inefficient because they continuously stay ON even in normal operation.

On the other hand, it does offer high-quality output because there is no gap during the switching between the source supplies. It completely isolates the output from the AC mains. Therefore, it helps in protection against the distortions or fluctuations in the AC mains.


What are Offline UPS?

What are Offline UPS?
The offline UPS is a type of UPS that directly supplies the power to the AC load from the AC mains in normal operation and uses an inverter to power the AC load from the DC battery. Since there are two separate lines of supplies, the output supply must be switched between the two sources.

The switching speed of an Offline UPS is around 5ms which is enough to keep a computer from shutting down. But not fast enough to keep a smooth operation of sensitive equipment in hospitals.

During normal operation, the power from AC mains is directly supplied to the output through a static transfer switch. At the same time, the AC is converted into DC using a rectifier to charge the battery using a charge controller. But unlike Online UPS, the inverter does not draw current from the battery until the primary supply (AC main) is interrupted.

When the primary supply breaks, the battery stops charging, and the static switch transfers the output line to the inverter side very quickly. At the same time, the inverter starts drawing current from the battery which is then supplied to the AC load.

Since it stays off when it draws current from the AC line during normal operation, it is known as Offline UPS.

The Offline UPS mostly stays off in normal operation and because of that, the temperature of the components stays low. Therefore, it requires smaller heat sinks and the components with a lower tolerance can be used which also decreases the overall cost of the offline UPS.

Since it stays off in its normal operation and does not use the battery continuously, the efficiency of the system increases.

But the downside of offline UPS is that the directly supplied AC is not completely isolated from the load. Therefore, there is no protection between the load and source and the distortion or fluctuations in the Ac mains can damage the connected load.

Differences between Online UPS and Offline UPS

The UPS that supplies power from the AC mains to the load through the rectifier and inverter combination The UPS supply the AC mains power directly to the load.
It continuously draws current from the battery. It only draws current from the battery during primary source failure or power outage.
It requires a large battery charger circuit because it carries the entire load current. It requires a small charger circuit because it only charges the battery.
The input supply and the load are completely isolated. There is no isolation between the input supply and the load.
It has high-performance output because it protects the output load from input voltage spike and distortion. Its performance reduces with the input voltage distortion; which is directly connected to the load.
There is not switching between the source, hence no time delay It uses a static transfer switch to switch between its source with a time delay of 5ms
It stays ON almost at all times. It turns ON only at power failure.
Due to its continuous ON condition, it is inefficient and unreliable. It is more efficient and reliable because it mostly stays off.
It requires large heat sinks because of the high operating temperature It requires smaller heat sinks because of low operating temperature due to its off state mostly.
The components used must have the tolerance to withstand high temperature There is no need for the components to have high-temperature tolerance.
It is expensive than Offline UPS. It is cheaper than Online UPS.
It is used for very sensitive electronics that cannot tolerate any gap between supplies such as in-hospital ICUs Offline UPS is used for electronic equipment that can tolerate a delay of 5ms such as Computer etc



3 Phase Online Transformer-based IGBT UPS
●High efficiency up to 95%
●Wide input voltage range
●Galvanic isolation
●High overload capacity
●IGBT-based rectifier technology

High reliability

• Wide input voltage range ( -40%~+25%) assure high grid adaptability and prolong battery service life.
• Dual air ducts design shows the better cooling performance
• Dual power and DSP redundancy design get higher reliability
• Water, Dust, and Corrosion resistant coating in all PCB boards
• Robust EMC Performance due to electromagnetic shielding tech
• Intelligent fan speed control and failure detection function reduces the noise and prolongs the fan service life

Green power

• High input power factor(Up to 0.999) and low Input THDi: <2.0% at full load, much less grid pollution, and costs
• Low output THDv: <0.5%, higher adaptability to a precision instrument
• High efficiency in online mode >95% and ECO mode efficiency>99%. 50%load >94.74%
• Load Bus sync (LBS) control decreases the transfer time and current impact of the dual bus system.
• Self-aging test function without load enables the on-site commission

Completed galvanic isolation

• Completed UPS output galvanic isolation for key components from the high voltage DC
• Full isolate from the external loads, reduce the harmonic disturbances
• Short circuit protection, restrain the high current puncture to UPS
• No effects to the UPS output performance or reduced impact of the inverter power components whilst supplying specific loads

Intelligent Management

• Intelligent SNMP and MOD BUS achieves local monitoring and remote monitor
• Intelligent battery management, automatic boosting, and floating charge control
• Intelligent fan control according to the load capacity reduces the noise and prolongs the fan service life
• Smart programmable dry contact communication function
• Battery self-test function and battery temperature compensation function improve the battery performance and extend battery use life

Humanized Operation

• Easy operation with 7 inch LCD touch screen and LED on the front door
• Easy to working modes setting by touch screen: Output voltage, Frequency, ECO mode, charging current and battery cells
• ON/OFF – Double Button design to prevent misoperation and touch screen failure
• EPO (Emergency Power off) button on the front panel
• Large data storage capacity, 10000pcs events logs

More Options

• UPS management software
• SNMP & MODBUS communication
• IP grade upgrade & temperature sensor
• Lightning protection device C/D level
• Charging temperature compensation
• Input/bypass isolation transformer

10KVA – 2500KVA

Brand and Origin


For any inquiry please inbox or call us 01401241354 or send us an email: [email protected] or log on to our website: www.worldshop.com.bd


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