Medium-voltage vacuum generator circuit breakers, drawout type GMSG-GCB
For 10 MW to 80 MW machines
Rated short-time withstand current up to 63 kA
Rated continuous current up to 4,000 A fan-cooled
Drawout type GMSG-GCB, medium-voltage vacuum generator circuit breakers
Drawout type generator circuit breakers for use in type GM-SG metal-clad switchgear are available. These circuit breakers are derived from the same type 3AH3 family of circuit breaker operating mechanisms as our standard non-generator circuit breakers. The basic design of the circuit breakers is the same, making maintenance and operation of the generator circuit breakers the same as for non-generator circuit breakers. This means that there is no incremental or additional training needed for your maintenance or operational personnel. The type GMSG-GCB generator circuit breakers exploit the long history of successful service provided by the entire type 3A (including types 3AF and 3AH operators) family of vacuum circuit breakers.
These generator circuit breakers fully conform to the requirements for generator circuit breakers as specified in IEEE Std C37.013, "IEEE Standard for AC High Voltage Generator Circuit Breakers Rated on a Symmetrical Current Basis."
Drawout type GMSG-GCB
- One-high or two-high drawout construction
- Up to 50 full-fault interruptions
- Front accessible circuit breaker operating mechanism for ease of maintenance
- Closed door racking
- Floor rollout circuit breaker in lower cell without a dolly
- Visible secondary disconnect
- Circuit breaker ships inside of cell, thus reducing installation cost and potential transit damage
- Pair with Siemens protective relays to provide complete generator protection
- Drawout type GMSG-GCB vacuum generator circuit breaker with type 3AH3 operating mechanism
- Uses the latest developments in vacuum interrupter technology
- Highly reliable vacuum interrupters - MTTF over 50,000 years
- Common type 3AH3 operator platform
- Over 120,000 type 3AH3 operators produced since 1998
- Generator circuit breakers tested to IEEE C37.013/C37.013a
- 10,000 operations to overhaul
- Three-cycle interrupting time (optional)
- Meets or exceeds the latest ANSI, IEEE, and NEMA standards
- UL or C-UL Listing available
- Available in lineups of conventional type GM-SG or GM-SG-AR switchgear, indoor or outdoor
- SIERS integrated electrical-racking system available (optional)
- Optional arc-resistant construction to ANSI/IEEE C37.20.7, up to 63 kA,
- 0.5 sec, accessibility type 2B.
For larger machines up to 200 MW, refer to Siemens stationary type vacuum generator circuit breaker offering.
Siemens integrated electrical-racking system (SIERS)
Features and benefits
Siemens integrated electric-racking system (SIERS) is an option that is available with Siemens type GM-SG non-arc-resistant and GM-SG-AR arc-resistant, medium-voltage switchgear. It 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.
- 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.
- 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 type GM-SG non-arc resistant and GM-SG-AR arc-resistant, medium-voltage switchgear.
Type SIERS device is available in three configurations:
- Basic version
- Local HMI version (Sm@rtGear™ power distribution solution)
- Custom version (i.e., SCADA or other system).
1 Interrupting time is based on the first current zero occurring not later
than 66 ms after fault initiation, for example, %dc component <100.
2 Interrupting time of 50 ms available, provided that the first current
zero occurs no later than 50 ms after fault initiation.
3 "xxxx" in type designation refers to the continuous current rating 1,200 A,
2,000 A, or 3,000 A, as appropriate. The 4,000 A fan-cooled rating is
achieved using a 3,000 A circuit breaker in combination with fan cooling
in the switchgear structure (indoor only). Assuming 13.8 kV generator
voltage and load current of 4,000 A with fan cooling.
TechTopics is a series of papers that discuss issues of interest to users or specifiers of electrical equipment.
- No. 02 - Loss of vacuum
- No. 14 - X-radiation emissions by vacuum interrupters
- No. 24 - Checking integrity of vacuum interrupters
- No. 44 - Anatomy of a short circuit
- No. 67 - %dc component
- No. 71 - Generator circuit breakers
- No. 72 - Generator circuit breaker applications - delayed current zeroes
- No. 73 - Generator circuit breaker applications - transient recovery voltage
- No. 77 - Residual voltage on load side of an open circuit breaker
- Entire TechTopics catalog