generator

Specialising in Diesel Generator Hire, cables, transformers, crane trucks

Diesel Generators are intricate machines requiring expert handling.  The end user of the generator only wants reliable power.

We provide a facility where generators are readily available in all sizes, together with the necessary equipment and expertise to move them to site swiftly and safely, and have them reliably operational during the required period, allowing our customer to concentrate on their own work.  All this at a minimum charge by being able to utilise the machinery more efficiently through a larger customer base.

Hence we provide an alternative power solution that is more reliable, more flexible easier and cheaper than operating own generators.

Generator Fleet

The fleet of rental diesel generators for 3 phase applications is kept on standby 24 hours/ day, 7 days per week, to be able to deliver emergency backup power in mobile locations, wherever it is required by our wide spectrum on customers.  The generator fleet is maintained by our in-house technical experts, and further supported by the group companies around South Africa.

Generators are available in ISO Containers, in sound proof containers, with AMF (Automatic Mains Failure), with synchronisation panels, and with full maintenance and backup support.

 

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Q&A

What is the advantage of hiring a generator over buying a generator?

Hiring has numerous advantages over owning a generator.

10 good reasons:

  1. Cost: A hiring company can optimise the asset usage better through a wider field of applications.  The generator is effectively used more efficiently.  This cost saving finances the hire company and enables a more cost effective solution to the customer.
  2. Availability:  A large fleet of generators ensures that the required generators are always available when the customer requires them.
  3. Backup & support:  When a replacement generator is required, this presents a major hurdle to the owner of a generator.  If a hire generator is used, this can be solved instantly with a telephone call!
  4. Quality: Using a company that specialises in generators ensures that the selection of equipment is done by knowledgeable experts.
  5. Hassle free: Hiring a generator takes the hassle out of generator usage, as it leaves all the hassle to the hire company.
  6. Maintenance: The generator hire company takes care of all required maintenance, allowing the customers to focus on their own work.
  7. Down time:  Down time is virtually eliminated by using a hired set, as generators requiring maintenance can be exchanged.
  8. Responsibility:  The responsibilities of buying and maintaining a generator is passed to the hire company.
  9. Capital outlay:  Hiring a generator avoids the high initial capital outlay required to buy one, leaving financial resources in tact for other projects.
  10. Tax advantages:  Hiring a generator is reflected as an operating expense.

 

What is the approximate diesel consumption of a generator?

A diesel generator effectively converts diesel to electricity.  Accordingly, more diesel must get burnt if more electricity is required.  As a rule of thumb, 0.3L of diesel must be burnt to produce1 kW for 1 hour.  For example, to calculate approximate fuel consumption for 300A of 380V 3 phase power at 0.8 PF:

300A x 380V x 1.73 x 0.8 / 1000 = 157kW

157kW x 0.3L/kW.hr = 47L/hr

Actual diesel consumption will vary according to efficiency, depending on the engine manufacturer and model, alternator make and model, operating environment, and the percentage of rated capacity of the generator.  Efficiency drops for light loads, as well as high loads when nearing rated capacity.

 

I have heard that generators are rated in kVA.  What is kVA, and why is this unit used to rate generators?

Strictly speaking, it should only be the alternator that is rated in kVA.  This unit is kilo (x1000) Volt x Amps, and is used because an alternator is limited in its capacity by the heating in the wiring, which is a product of Amps and Volts.  The limitation of the engine driving the alternator is obviously the kW which it is capable of producing at the required speed (typically 1,500RPM for 50Hz, 1,800RPM for 60Hz).  To match an engine to an alternator in manufacture, a power factor of 0.8 is usually assumed.

 

What size generator do I need?

Generators are given standby, prime, and base load ratings, depending on their application.  The required size of generator will typically be determined by the maximum load that has to be connected, and the maximum acceptable voltage and frequency drop, rather than the actual rating.  Surge currents, creating shock loads, such as during electrical motor starting, is often the limitation.  A motor may draw 3-7 times its running load during starting, depending on its configuration.  .

Sizing a generator to the requirement is one of the most commonly asked questions.

Typically however it is the size of the maximum load that has to be connected and the acceptable maximum voltage drop which determines the generator set size, not the ratings themselves. If the set is required to start motors, then the set will have to be at least 3 times the largest motor, which is normally started first. This means it will be unlikely to operate at anywhere near the ratings of the chosen set.

 

Can a generator be connected in parallel?

To connect generators in parallel, they must be synchronised, to ensure that the frequency and Voltage of the two generators matches closely.  Specialised equipment is required to do this, but it is possible.  To facilitate an easy alternative for our customers, We have generators in the fleet that are fitted with full synchronisation gear.  They can be synchronised to the mains or to another generator.  This provides a quick turnkey solution in situations where the existing supply or generator is insufficient in capacity, or it can be used as a redundant power supply.when the uninterrupted supply of power is critical .

 

What is an AMF Generator (Automatic Mains Failure)?

An AMF generator monitors the mains (or another generator), and starts up automatically when it detects a mains failure.  If fitted with an ATS (Automatic Transfer Switch), it will automatically disconnect the mains from the load, and change over to generator power.  When the mains returns, it will change back to mains and shut the generator down again.  We have AMF generators with pre-fitted ATS off the shelf in the hire fleet.