Live tank circuit breakers

We offer live tank circuit breakers for applications from 72.5 kV to 800 kV, up to 80 kA, suitable for all different types of applications, in extreme temperatures or earthquake regions. Depending on the requirement, you can choose from live tank circuit breakers with three-pole or single-pole operation, as well as from porcelain or composite insulators.

Main features

  • For applications from 72.5 kV to 800 kV, up to 80 kA
  • Spring drive mechanism (3AP) or electrohydraulic operating mechanism (3AT)
  • Self-compression principle (≤ 245 kV) or dynamic self-compression principle (≥ 245 kV)
  • Available with single- (FI, FE) or three-pole operation
  • Suitable for temperatures from -60 up to +55°C
  • Available with porcelain or composite insulators
  • Seismic withstand capability up to 0.3 g or 0.5 g
  • Gas leakage rate of less than 0.1 % per year
  • Type tested according to the latest international standards

Advantages

  • Easy installation and commissioning: only few subassemblies
  • Inspection after 12 and maintenance after 25 years
  • 10,000 switching operations are guaranteed
  • Service life of up to 50 years
  • Over 107,000 circuit breakers delivered worldwide prove our best practices and years of experience
  • Minimal transportation costs
  • 24-hour service hotline
  • Our global production network saves customers time and transportation costs

Our live tank product families

3AP circuit breaker family from 72.5 kV to 800 kV

Our high-voltage live tank circuit breakers are available for three-pole operation with a common base (FG), for single-pole operation also with a common base (FE) or for single-pole operation with separate bases (FI). 3AP1 circuit breakers up to 300 kV are equipped with one interrupter unit per pole and 3AP2 circuit breakers up to 550 kV include two interrupter units. The circuit breakers can be equipped with optional closing resistors (3AP3) for applications from 362 kV to 550 kV. The 3AP4 includes 4 interrupter units per pole and can also be delivered with closing resistors on request (3AP5).

 
 
 
 
 
 
 
3AP1
3AP2/3
3AP4/5
Rated voltage
kV
72,5
123
145
170
245
300
420
550
800
Number of interrupter units per pole
 
1
2
4
Rated power-frequency withstand voltage
kV
140
230
275
325
460
460
610
800
830
Rated lightning impulse withstand voltage / min
kV
325
550
650
750
1050
1050
1425
1550
2100
Rated switching impulse withstand voltage
kV
-
850
1050
1175
1425
Rated normal current, up to
A
2500
4000
4000
4000
4000
4000
5000
5000
5000
Rated short-circuit breaking current, up to
kA
40
40
40
40
63
40
80
63
63
Temperature range
°C
-60 up to +55
Rated operating sequence
 
0-0,3 s-CO-3 min-CO or CO-15 s-CO
Rated break time
 
3 cycles
2 cycles
Rated frequency
Hz
50 or 60
Maintenance after
 
25 years

All values in accordance with IEC, other values on request

The new 3AV generation is based on over 40 years of experience in the production of medium-voltage vacuum interrupters and over 6 million units delivered. Siemens Energy has introduced this proven technology to European power networks above 72.5 kV in 2010. Since 2017 the new vacuum live tank breakers up to 145 kV are manufactured and sold in series with more than 100 units delivered worldwide.

 

Advantages of vacuum switching technology:

  • Perfect for low temperature applications 
  • Suitable for frequent switching: high number of short circuit interruptions with excellent switching features 
  • Low maintenance efforts even with frequent breaking operations (“sealed for life” vacuum interrupter)
  • Switching medium (vacuum) with greenhouse potential (GWP) = 0
  • No CO2e emissions during operation, maintenance or recycling = minimized effort for gas handling 

 

Vacuum interrupting technology enables the implementation of clean air as an insulating medium in our Blue portfolio. Our clean air technology is the first F-gas-free insulation and represents an important step towards the company goal of developing completely environmentally friendly technologies.

  • 80% N2 and 20% O2, cleaned and free of humidity (synthetic air)
  • No global warming potential (GWP = 0) or ozone depletion potential (ODP = 0)
  • Non-toxic, non-flammable, very stable
  • Low boiling point, does not liquefy in low temperature applications
  • No accounting, documentation or reporting requirements
  • No CO2 compensation fees
  • No gas recycling required
Rated voltage
kV
72.5
145
Vs. SF6 breaker 145 kV
Number of guaranteed operations
at rated short-time withstand current (40 kA)
 
30
30
10-12
Number of interrupter units per pole
 
1
1
1
Rated break time
 
2cycle (50 Hz)
2cycle
3cycle
Rated normal current, up to
A
3150
3150
3150
Rated short-time withstand current, up to
kA
40
40
40
Rated short-circuit breaking current, up to
kA
40
40
40
Rated frequency
Hz
50 / 60
50
50 / 60
Rated power-frequency withstand voltage
kV
160
275
275
Rated lightning impulse withstand voltage
kV
350
650
650
Rated duration of short-circuit
s
3
3
3
Rated peak withstand current (2.7 p.u.)
kA
108
108
108
First-pole-to-clear-factor
p.u.
1.5 / 1.3
1.5 / 1.3
1.5 / 1.3
Capacitive voltage factor
p.u.
1.7
1.4
1.4
Temperature range
°C
-60 up to +55
-60 up to +55
-30 up to +55
Maintenance after
 
12 years visual inspection
25 years visual inspection
up to 10,000 operations at 3150 A
12 years visual inspection
25 years visual inspection
up to 10,000 operations at 3150 A
12 years visual inspection
25 years revision
up to 6,000 operations at 3150 A
Insulating medium
 
Clean Air
Clean Air
SF6
Amount of SF6 / CO2 equivalent / Global Warming Potential
 
0 / 0 / 0
0 / 0 / 0
9,2 kg / 209,760 kg / 209,760
Downloads, support and services

Our services for you

You can find details on our live tank circuit breakers and information about our services here.

We can gladly help you with installation, commissioning, diagnostics and malfunctions

Testing laboratories at Schaltwerk Berlin

We test components at our accredited testing laboratories.

Testing laboratories at Schaltwerk Berlin

Numerical simulation and analytical calculation methods for efficient product development.