Here are five key considerations you should focus on when Buying diesel generator – 5 tips:
TIP 1: SIZE REALLY MATTERS
The most important thing to consider when sizing a generator is the high inrush currents associated with starting electric motor. This is typically six times the full load current. However, inrush currents for the type of high-efficiency motors being specified today can be almost double that amount.
This approach often resulting in over sizing the generators. The motor running load and not based on the actual needs of the application. Moreover, it disregards other key factors that play a key role in sizing the generators. For instance, harmonics caused by variable frequency drives and sequential starting of motors.
Thankfully help is at hand. Many generators can now be equipped with solutions to overcome the extra systems required in the alternator.
Typically, two options are offered:
Permanent magnet or auxiliary winding. Both provide the generator with three times their nominal current to cover inrush peaks. From the electrical motor, for a minimum duration of ten seconds, via a residua excitation current.
In certain cases, even more, advanced options are available. For instance, some generators feature a digital automatic voltage regulator (D-AVR). This type of voltage controller allows operators to downsize the generator requirement..
Option
Another option could be to use a system that closes the breaker just when the engine starts to run. This enables the excitation to increase gradually as the speed of the engine does. Allowing for very soft start of loads connected to the generator.
This is especially useful for the magnetising step-up transformers in installations where a medium voltage is required.
It is no longer necessary to buy larger generators than needed to cope with the initial electrical surge upon starting. What’s more, with smart control of the generator’s voltage, it is possible to achieve lower fuel consumption. And reduced maintenance cost and longer lifetimes.
TIP 2: MODULAR CAPABILITY – Buying diesel generator – 5 tips
Even if starting off with just one unit, it’s worth asking the equipment manufacturer what steps can be taken. Generators can be parallel a single generator with others to form a modular power plant set up. Also, how long would it take to pair two units? With many generators, this process can take under 10 minutes, but not all offer this capability.
When coordinated by a network of controllers, plug-and-play generators can power up and down according to the on-site power requirements at any given time. For example, only one or two may be operational during periods of low load, thereby boosting fuel efficiency. Equally, all units may become active in periods of high demand.
There are a number of additional benefits from modular capability. It isn’t necessary to stop the entire power delivery during essential maintenance operations.
TIP 3: CONTROL SYSTEMS AND POWER MANAGEMENT
The ideal control system should offer a variety of features. For instance, the ability to remotely start and program the machine. You can set the display warnings, for instance, low fuel and other performance issues. This helps to better utilise the efficiency of the power plant. While providing a valuable overview of the application process.
Many generators are now equipped with Power Management Systems (PMS). What makes them ideally suited for rental applications is the plug-and-play design that allows for easy and rapid configuration. PMS provides the means to optimise the fuel consumption and performance of generators in parallel with load demand. Starting and stopping units with a corresponding increase or decrease of the load. It also helps avoid engine damage to generators from running with low load levels, thereby increasing their useful work life.
TIP 4: FUEL EFFICIENCY AND AUTONOMY
Mobile generators now consume much less fuel than was possible five years ago. The fact that the latest equipment can run for longer and more economically. Has been a big driver behind the market’s growth. However, not all generators are the same and fuel can be expensive.
Furthermore, modularity also contributes to fuel efficiency. For example, taking the demand patterns of a typical industrial application as a guide. The deployment of a 1 MVA generator as a prime power source can use up to 1.677 litres of fuel being consumed a day. That compares with approximately 1.558 litres of fuel if three 325 kVA generators were doing the same job.
The options for fuelling generators are expanding nowadays and now include biogas and natural gas. Market is emerging, and it is important to discuss these technologies with a manufacturer. Before investing in a new generator.
TIP 5: PHYSICAL SIZE AND TRANSPORTATION
When using multiple generators, it’s also worth considering if units can be stacked on top of each other for minimum footprint and access considerations.
These factors have a bearing on total operating expenses and efforts to reduce carbon costs.
CONCLUSION
Consider all the foregoing factors that affect the choice of appropriate sizing. If in doubt, a simple rule for estimating motor starting: For instance, 1 kW of generator set rating per ¾ to 1 hp specified on the motor.
The more accurate the sizing is to the application, the better the results.
It will pay to think modular because bigger is not necessarily better. Modular is not just about large installations. It can make a lot of sense with units around the 150-kVA level as well.
Buying a diesel generator – 5 tips.
Article from: https://www.redstarequipment.com.au/2018/05/5-tips-for-buying-a-diesel-generator/
