
Siemens Air-Cooled Generators 
SGen-100A-4P Series
with ratings from 25 MVA up to 70 MVA
SGen-100A-4P Series at Generator Plant Erfurt, Germany
As one of the international market leaders 
in the manufacturing of synchronous 
machines, Siemens has accumulated many 
decades of experience in the production 
of generators. Proven four-pole air-cooled 
generators, from our SGen-100A-4P series, 
are the Siemens answer for turbine generators in industrial plants.
Answers for energy.
Our air-cooled generators are developed 
by using state-of-the-art methods. By 
working with special computer programs 
for calculation, design and production, 
we can optimally match the generators 
to the customers’ needs.

Four-pole three-phase synchronous generator
Outstanding design features of the 
Siemens air-cooled SGen-100A-4P series 
generators include:
high efficiency,
 ■
low noise emissions, ■ 
low installation and  ■ 
commissioning costs,
 ■
high serviceability and 
long service life. ■
For each customer project, a customized 
generator is developed according to the 
individual technological specifications, 
output and customer needs. Using a 
modular building-block system, the 
required generator type is designed by 
choosing from different diameters and 
by making adjustments to length. This 
enables us to supply our customers with 
generators specially tailored to their 
requirements. As an option, the generator 
can also be supplied with a gearbox.
Siemens four-pole three-phase synchronous generators are used as high-voltage 
generators with a solid salient-pole rotor. 
Their rotor windings are indirectly cooled 
by air.
These generators use brushless excitation 
as a standard. The exciter power is supplied 
by an exciter with rotating rectifiers. The 
exciter is a stationary-field machine with 
the rotor mounted on the generator shaft. 
Alternatively, static excitation using slip 
rings is also available.
The standard design is IM 1005 featuring 
a frame with end shield bearings.
Industrial plants equipped with steam and 
gas turbines, and SGen-100A-4P series 
generators keep process costs down due 
to high efficiency levels of cogeneration. 
This ensures a considerable degree of independence from public power supply.
5
4
3
1
2
6
7
8
1
 Blower
2
 Exciter Current Conductor
3
 Journal Area
4
 Rotor Shaft
5
 Coupling
9
6
Pole Winding Support
7
 Rotor Coils
8
 Pole Shoe
9
 Pole Shoe Screws
2

1
 Welded casing
2
 Stator winding and insulation are form-
wound coils featuring Siemens epoxy-mica 
(MICALASTIC®) insulation technology
3
 Salient-pole rotor with solid pole shoes
4
 Stator core
5
 The coolers are implemented either in 
1
, CACA2 or DAC3 cooling systems
TEWAC
6
 Brushless exciter set with or without 
Permanent Magnet Generator (PMG)
 1 TEWAC = Totally Enclosed Water-to-Air Cooling
 2 C ACA = Closed Air-to-Air Cooling
 3 DAC = Direct Air Cooling (cooling air intake via filter)
5
4
2
3
6
1
Technical data
Frequency Model Power factor Apparent power Efficiency Terminal voltage
50 Hz SGen5-100A-4P 0.80 to 0.90 25 MVA to 70 MVA up to 98.5 % 6.3 kV to 15.0 kV
60 Hz SGen6-100A-4P 0.80 to 0.90 25 MVA to 65 MVA up to 98.5 % 6.3 kV to 13.8 kV
3

SGen-100A-4P Series Air-Cooled Generators: References
Wesel, Germany 
Waste incineration plant (AEZ)
Performance
Generator Type: SGen5-100A-4P
Apparent Power: 27.7 MVA
Terminal Voltage: 10.5 kV
BEC Cuijk, Netherlands 
Wood-fired cogeneration power plant (CHP)
Performance
Generator Type: SGen5-100A-4P
Apparent Power: 38.1 MVA
Terminal Voltage: 10.5 kV
Published by and copyright © 2010: 
Siemens AG 
Energy Sector 
Freyeslebenstrasse 1 
91058 Erlangen, Germany
Siemens Energy, Inc. 
4400 Alafaya Trail 
Orlando, FL 32826-2399, USA
For more information, please contact 
our Customer Support Center. 
Phone: +49 180/524 70 00 
Fax: +49 180/524 24 71 
(Charges depending on provider) 
E-mail: support.energy@siemens.com
Eilenburg, Germany 
Stora Enso paper mill
Performance
Generator Type: SGen5-100A-4P
Apparent Power: 42.2 MVA
Terminal Voltage: 10.5 kV
For more information please contact 
your local Siemens sales representative.
Fossil Power Generation Division 
Order No. E50001-G210-A123-V1-4A00 
Printed in Germany 
Dispo 34802, c4bs No. 7449 
TH 214-100697 431564 DB 12103.0
Printed on elementary chlorine-free 
bleached paper.
All rights reserved. 
Trademarks mentioned in this document 
are the property of Siemens AG, its affiliates, 
or their respective owners.
Subject to change without prior notice. 
The information in this document contains 
general descriptions of the technical options 
available, which may not apply in all cases. 
The required technical options should therefore 
be specified in the contract.
www.siemens.com/energy