Open technical binder on a workshop desk showing a generating set specification page with tables and a dimensional drawing, a torch and safety glasses beside it

Section index · technical resources · 20/06/2026

Technical Datasheets

A datasheet is a dense page and almost everyone reads it in the wrong order. The headline output is at the top; the conditions that make it meaningful are in small type at the bottom.

This page sets out the standard blocks and what to check in each, as a companion to the documentation library.

Fix your requirement first Documentation library

A technical datasheet for a generating set is a dense page, and almost everyone reads it in the wrong order. The headline output is at the top; the conditions that make the headline meaningful are usually in small type at the bottom. Read from the bottom up and the sheet becomes far more useful.

The English-language sheets used across this market follow a broadly common structure, which makes side-by-side comparison possible once you know which line to look at.

Printed specification sheet on a desk showing a fuel consumption table and a dimensional drawing, a ruler and a pen marking one row — The consumption row at 75 per cent load is the number that predicts the fuel bill, and it is rarely the one quoted in a sales conversation.

The rated output block

This is the part that should be read with the duty classes in mind. A well-constructed sheet gives two or three figures for the same machine: emergency standby power, prime power and, sometimes, continuous power, each in both kVA and kW, at a stated power factor of normally 0.8 lagging. The gap between the standby and prime figures is usually around 9 to 10 per cent.

Under those figures sit the reference conditions: ambient temperature, altitude and sometimes relative humidity, following ISO 3046 for the engine and ISO 8528 for the set. If the sheet quotes 25 degrees Celsius at sea level and your plant room reaches 45 degrees at 1,200 metres, the headline figure is not the figure you will get. The corrections are worked through in the sizing method.

Block	Key lines	What to check
Rated output	Standby, prime, continuous kVA and kW	Which class the quoted figure belongs to
Reference conditions	Ambient, altitude, power factor	Whether they match your site
Engine data	Model, displacement, aspiration, speed	Full model designation, not the brand
Alternator data	Model, insulation class, reactance	Class H insulation, winding type
Fuel consumption	Litres per hour at 25, 50, 75, 100 %	The load you will actually run at
Cooling	Rated ambient capability of the radiator	Often lower than the engine's limit
Dimensions and weight	Length, width, height, dry and wet weight	Access route and foundation
Sound level	dB(A) at a stated distance	Which distance, 1 m or 7 m

Fuel consumption, and the load that matters

Consumption is normally tabulated at 25, 50, 75 and 100 per cent of the rated load. The temptation is to read the 100 per cent figure and multiply. The useful figure is the one at the load the machine will actually carry, which on a prime power installation is commonly between 50 and 80 per cent, and the difference over a year is substantial.

Two warnings attach to these tables. They are measured at the reference conditions, so a hot site changes them. And they are measured on a specific fuel specification, which matters where local fuel differs, a question connected to the tank problems described in the fuel tank guide.

Sound level at which distance?

A sound pressure figure means nothing without the distance and the condition it was measured at. Sheets quote at 1 metre or at 7 metres, and occasionally at full load or at 75 per cent. A 7 metre figure looks around 15 dB better than a 1 metre figure for the same machine. Compare like with like or do not compare at all.

Enclosure and options

The enclosure section covers the canopy or container, its ingress protection rating under IEC 60529, the acoustic treatment fitted, the base fuel tank capacity and the autonomy that gives at a stated load. Autonomy is another figure that depends on the load assumed, so an eight hour tank at 75 per cent is a six hour tank at full load.

Options typically listed include the controller model, the circuit breaker rating, the battery charger, the jacket water heater and the anti-condensation heater. Of these, the jacket water heater is the one that decides whether a standby machine can take load quickly in a cold plant room, and it is worth confirming rather than assuming.

Using a sheet properly

The working method is short. Fix your own requirement first, using the sizing calculation. Then read each sheet from the reference conditions upward, correcting the rated output to your site. Then compare consumption at your actual load, not at full load. Then check the physical envelope against the access route. Only then look at price.

For the engine model designations that appear in the engine data block, the platform pages in the generator set section give the context, and the documents that should accompany the sheet in a project file are listed in the technical documentation library.