Medium- and low-voltage system services

Field Engineer testing switchgear
Medium-voltage system services from Siemens

More than 1.2 million

installed medium-voltage systems around the world

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Ensuring fault-free operation of medium- and low-voltage switchgear

To guarantee efficient and safe power distribution, it is key that medium- and low-voltage switchgear in power networks operate in a highly reliable manner and comply with performance requirements, despite age and wear. Our customer-focused Siemens service centers offer all services needed to keep your switchgear functioning and up-to-date. We service Siemens products as well as other OEM products. 

Keep your medium- and low-voltage equipment in its best possible shape

Even the most reliable and rugged distribution assets are subject to wear and aging as they can be in operation for decades. To avoid expensive failures and downtime, your medium-voltage equipment needs excellent care and ongoing service. That’s why Siemens can support you throughout the entire lifecycle of your equipment. Siemens services for medium-voltage products range from installation and commissioning, planned maintenance and inspections, repair, emergency services and spare parts, to modernizations and extensions, trainings, asset management, and monitoring and diagnostics.

Medium-voltage solutions and support

Product support for new and legacy equipment, retrofit, and replacement circuit breakers for most OEM brands. 

As the supplier of OEM parts for your Allis-Chalmers and Siemens medium-voltage switchgear and circuit breakers, Siemens is committed to supporting you with qualified parts and factory-trained field service throughout your products' life cycle. Siemens has a comprehensive database of drawings and manufacturing capabilities to fabricate a direct match. We design and manufacture all interfaces and extensions, including bus work and protection and control panels. Siemens factory-trained field service technicians will work with you to install, connect, test and commission your switchgear and match-in-line extension.


Medium-voltage vacuum replacement contactors


Medium-voltage vacuum replacement contactors provide a cost-effective way to upgrade your system capabilities to current vacuum technology while increasing equipment reliability and minimizing downtime. Siemens supports the Series 81000 controller product line and can provide replacement solutions for most 85H, 88H, 90H, 93H, 94H, 96H, 97H, and 98H contactor models.



  • New switchgear boasting the latest technology
  • Medium-voltage motor controllers - 5kV to 15kV
  • Add-on sections for legacy switchgear
  • Replacement parts
  • Replacement circuit breakers
  • Replacement contactors
  • Ground and test devices
  • Medium- and low-voltage circuit breakers to replace most brands
  • Closed door racking solutions
  • Training onsite or at our factory
  • Service on medium- and low-voltage products
  • Protection and control service and products.

Outdoor distribution circuit breaker support capabilities

Spare Parts Availability
Replacement Vacuum Breakers Availability
Add-on Sections Availability
Field Service Availability
Training Availability
Siemens (Vacuum)

AIS (air-insulated) switchgear support capabilities

Spare Parts Available
Replacement Circuit Breakers Available
Add-on Sections  Available
Closed Door Racking Solutions Available
Field Service Available
Training Available
Siemens (Vacuum)
Allis-Chalmers (All Air-Magnetic)
IV Gear
I Gear
F Gear
D Gear
R Gear
ME Gear
L Gear
H Gear

GIS (gas-insulated) switchgear support capabilities

Spare Parts Availability 
Add-on Modules Availability 
Field Service Availability 
Training Availability
Siemens (GIS)
8DJH 36

MVC (medium-voltage control centers) support capabilities

Spare Parts Availability 
Replacement Vacuum Contactor Availiability
Add-on Sections Availability
Field Service Availability
Training Availability
Siemens (Vacuum)
Series 81000
Transition to Simovac
Transition to Simovac
Transition to Simovac
Transition to Simovac
Transition to Simovac
Transition to Simovac
Transition to Simovac
Transition to Simovac
*Cell conversion kits are often needed to fit a new contactor into an old cell.

Service solutions for every need of your medium and low voltage systems

Continue running your business without electrical worries. Whether you want to increase your system’s availability and lifetime or you need an extension, there is always a solution we can provide to you. With Siemens, you benefit from over 160 years of OEM experience and nearly 50 years of OEM experience in the field of medium and low voltage equipment. 

Siemens technology

Protection and control upgrades

Many electric system operators need to modernize their protection and control systems in existing facilities. Siemens SIPROTEC relays offer protection and control for transmission, generation, distribution, and industrial applications. Siemens can replace old relays with new SIPROTEC relays in the existing panels, or we can fabricate new panels. Siemens also provides the necessary engineering, documentation, relay settings, commissioning, and aftermarket services to keep your equipment performing reliability and safely long after the equipement has been put in service. 

OEM-certified parts and components

Siemens maintains a multi-million-dollar inventory for rapid supply of many key components. Siemens supports not only current production products, but also legacy medium and low voltage products. 

Operating mechanisms

The 3AF/3AH mechanism comes equipped with a spring charge motor mechanism, which includes a lifetime lubricated gear box. Additionally, its superior construction includes roller bearings, bushings, and machined latches and cams.


The stored energy operating mechanism of the GMI circuit brekaer is an integrated arrangement of springs, solenoids and mechanical devices designed to provide a number of critical functions. The energy necessary to close and open the contacts of the vacuum interrupters is stored in powerful tripping and closing springs. The closing springs are normally charged automatically, but there are provisions for manual charging. The operating mechanism that controls charging, closing, and tripping functions is fully trip-free, i.e., spring charging does not automatically change the postions of the primary contacts, and the closing funciton may be overridden by the tripping function at any time. 

Vacuum interrupters

Siemens vacuum interrupters are among the best in class in short-circuit breaking capacity. They offer: 

  • 30,000 circuit breaker operation cycles
  • Five million operation cycles for contactors
  • Maintenance-free service life
  • Extremely high short-circuit breaking capacity
  • High dielectric performance
  • Very low chopping currents
  • Minimal contact resistance.

Our portfolio offers predictable and stable interruption over the entire product lifetime, even for extreme applications such as: 

  • Vibrating environments
  • High and low frequencies
  • Horizontal or vertical installation.

In Siemens, you have a reliable and innovative partner with vast experience in vacuum switching technology:

  • First patent in the 1930s
  • More than 40 years of in-depth market experience
  • In-house contact material production
  • More than five million units installed in different applications throughout the world.

Our vacuum interrupters are well established in all industries, including:

  • Power utilities
  • Steel mills
  • Wind turbines
  • Shipping
  • Off-shore
  • Railway.

Medium-voltage vacuum roll-in replacement circuit breakers

Vacuum roll-in replacement circuit breakers provide a cost effective way to upgrade your system capabilities while saving you from costly maintenance and lost productivity.


Whether your original air-magnetic switchgear was made by Allis-Chalmers, Westinghouse, GE, Federal Pacific, ITE, McGraw Edison, or another manufacturer, we will assist you to evaluate the Siemens vacuum replacement, retrofit, or retrofill option that best meets your needs.


Why replacement circuit breakers?

  • Increased reliability and performance

  • Reduced operating and maintenance expenditures

  • Reduced downtime and minimal changeover time during power switchgear modification or conversion

  • Preserved investment in existing cubicles

  • Improved employee and environmental safety.

Low-voltage replacement circuit breakers

Low-voltage replacement circuit breakers provide a cost-effective way to upgrade to current technology while increasing equipment reliability and minimizing downtime. Our low-voltage replacement circuit breakers utilize the proven Siemens WL circuit breaker for the core operator, main contacts, and accessories, and they are designed so that the primaries connect directly to the existing bus.  Our direct-rack connection eliminates the need for intermediate connections between the original bus and the new circuit breaker, therefore also eliminating potential heat and loss of efficiency due to increased resistance and removing any additional points of failure or maintenance.

  • Direct-connect to the primary contact mitigates heat generation

  • Features Siemens WL operator 

  • Trip modules for all applications

  • Secondary contacts mounted on front for safe, easy access

  • Remote operation and monitoring for safety

  • 24/7 support line.

Remote racking solutions

Siemens provides cost effective remote circuit breaker racking solutions to keep operators clear of the arc flash zone during circuit breaker racking.

Allis-Chalmers D and F gear

Closed door racking


In order to improve operator safety, Siemens offers a cost effective field modification to convert type D and F switchgear to a closed-door, remote rack design. This modification provides a cost effective solution to keep operators clear of the arc flash zone during breaker racking.

Allis-Chalmers and later Siemens manufactured type D and F medium-voltage switchgear from 1958 through the late 1980s. This gear utilized air-magnetic circuit breakers that were typically manually racked via a lever while the cubicle panel door was open.




Original floor-mounted lever racking, commonly used on type D and F switchgear, required the operator to stand in front of the circuit breaker with the panel door open. 
The field modification consists of a floor-mounted screw racking device and breaker-mounted bracket to interface with the floor-mounted screw device. These additions allow end-users to either have closed-door manual racking or closed-door remote racking.




Following the field modification, the circuit breaker can be racked in and out while the operator stands outside of the arc flash zone.

The closed-door remote racking option requires the above mentioned cell and circuit breaker additions, as well as a minor front panel modification to accept a torque-regulated motor. The motor can be moved from one position to the next, thus only one motor device is required.


Watch the Closed Door Racking video here

Siemens 5-38 kV GM Switchgear

Remote Racking Modification


In order to improve operator safety, Siemens offers a field modification to convert 5 - 38kV type GM switchgear to a remote rack design. This modification provides a cost effective solution to keep operators clear of the arc flash zone during circuit breaker racking.

Siemens began manufacturing GM medium-voltage switchgear in the late 1980s and still manufactures this equipment today. This gear utilizes vacuum circuit breakers that are manually racked via a hand crank while standing in front of the cubicle.

The remote racking option requires a minor front panel modification to accept a torque-regulated motor. The motor can be moved from one cell position to the next, thus only one motor device is required.




Original hand crank racking, commonly used on GM switchgear, requires the operator to stand in front of the circuit breaker with the panel door open. 




Following the field modification, the circuit breaker can be racked in and out while the operator stands outside the arc flash zone. 

Remote Breaker Racking Device (RBRD)

The Siemens Remote Breaker Racking Device (RBRD) provides maintenance personnel the ability to safely rack Siemens Type WL circuit breakers and Siemens DirectRackTM replacement circuit breakers into the connect, test, and disconnect positions from up to 30 feet away from the breaker.


The use of breaker door mounting brackets reduces installation time and effort. The RBRD unit slides into retaining slots on the door mounting brackets and are secured in place with retaining pins. The RBRD has integral torque overload sensing that prevents damage to the breaker racking mechanism. The device racks the breaker to the disconnect position first, then proceeds to the user selected position.


The user doesn’t have to pre-determine the breaker position prior to the RBRD operation. The user simply installs the device in the mounting brackets, selects the desired position selector switch setting on the remote pendant, and presses the green start button. When the selected position is reached, the appropriate remote pendant position indicator will illuminate continuously.


Retrofitting existing low voltage switchgear and switchboards with the RBRD unit is easily accomplished. RBRD mounting brackets can be ordered and installed in the field.  

Siemens Integrated Electric-Racking System (SIERS)

Features and benefits


Siemens integrated electric-racking system (SIERS) provides additional personnel protection against arc-flash exposure for operators by providing a means of remotely racking the type GMSG drawout circuit breaker. SIERS reduces the need for personal protective equipment (P.P.E.) per the NFPA-70E® standard.


Standard features:

  • Maintain all of the safety interlocks as required by IEEE standard C37.20.2
  • Logic control module for control and circuit protection
  • Interference detection
  • Control pendant (hand-held controller)
  • High-torque, fixed-mounted dc motor
  • Available for 125 V dc external power supply
  • Factory installed and tested as a complete racking system.

Optional features:

  • Powered from 120 V ac sources in switchgear
  • Provision for external power source
  • Integrated into the switchgear secondary control circuits or with the protection relay to provide interface with local HMI or SCADA systems
  • Field retrofit for existing Siemens non-arc-resistant, medium-voltage switchgear.

Optional configurations:

Type SIERS device is available in three configurations:


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Mailing address

Siemens Industry, Inc.

7000 Siemens Road

Wendell, North Carolina 27591

United States