Design Guide DG022010EN Effective February 2020 Medium-voltage power distribution and control systems > Switchgear > Metal-enclosed switchgear, MSB utilizing medium-voltage switch and vacuum breakers Contents General Description ........................... 7.2-2 Standard MSB Switchgear and Assembly Ratings .. 7.2-3 Devices ..................................... 7.2-4 Circuit Breakers ............................. 7.2-4 Protection Relays ............................ 7.2-5 System Options ............................. 7.2-6 Layouts and Dimensions ...................... 7.2-9 Standard ................................... 7.2-9 Application Data ............................. 7.2-12 Weights ................................... 7.2-12 Application Examples ......................... 7.2-12 More about this product Eaton.com/mvs Complete library of design guides Eaton.com/designguides Metal-Enclosed Switchgear, MSB Design Guide DG022010EN Utilizing Medium-Voltage Switch and Vacuum Breakers Effective February 2020 General Description 7.2-2 General Description Eaton’s MSB assemblies (metal-enclosed Eaton Type MSB switchgear provides a Type MSB vacuum switchgear switch and breaker) consist of a load small footprint using vacuum breaker meets or exceeds the following interrupter switch (Type MVS) in series technology where the breaker rating industry standards: with a fixed mounted vacuum circuit does not exceed 1200 A continuous and breaker (Type VCP-TR for 5–15 kV) in a interrupting ratings are not exceeded. ■ ANSI/IEEE C37.20.3 metal-enclosed cabinet. This combination All protective devices and meters are ■ ANSI/IEEE C37.20.4 has been designed primarily where a conveniently mounted on the switchgear ■ ANSI C37.22 vacuum circuit breaker is required for structure door. ■ higher interrupting capacities and a switch ANSI C37.57 is required to provide a visible means of The VCP-TR vacuum breaker is a fully ■ ANSI C37.58 rated two-step stored energy circuit disconnect. As primary protection for ■ NEMA SG5 single-ended substations, it can eliminate breaker with an “open-close-open” ■ NEMA SG6 the need for a secondary main circuit duty cycle. The interrupting rating is breaker. It can also be applied as the 25 kA or 40 kA from 4.76 kV to 15 kV and ■ CSA 22.2 No. 31 has a front access mecha nism. Type primary main device and integrated with ■ EEMAC G8-3.3 fused or unfused feeder switches in a VCP-TR circuit breakers can be supplied ■ CSA listable for Canada and lineup of MVS switchgear. Two and three with an integral trip unit for phase and U.S. markets breaker automatic transfer schemes are ground over current protection. also available. The vacuum circuit breaker interrupter MVS switch sections are easily combined with MSB sections in lineups. No bus With the vacuum circuit breaker, connections have been designed with transitions are required between them Type MSB switchgear assemblies a flex current transfer system that except where a bus transition is needed utilize an overcurrent protective provides a unique non-sliding current such as between main and feeder sections. device that provides increased system transfer arrangement, which eliminates protection and increased coordination maintenance, excellent electrical and with upstream and downstream devices thermal transfer, and long vacuum where these benefits cannot be achieved interrupter life. with a switch and fuse combination. A visible disconnecting means is Vacuum circuit breakers provide the accomplished by the load break air following features: interrupter switch and viewing window. ■ High interrupting capacity suitable for Both indoor and outdoor non-walk-in use with ground fault equipment and enclosures are available. Applications differential relay schemes include single unit lineups and transformer primary applications. ■ Load Break Switch providing visible Configurations with an auto matic means of disconnect without opening transfer control system can be easily the door accommodated. Fixed vacuum breakers ■ High duty cycle are ideal for high duty cycle, as well as ■ Adjustable overcurrent protection applications requiring rapid return to service after a fault. ■ Expanded protective relay functions, such as those provided in the EDR-5000 Type MSB switchgear is the product ■ Three-phase tripping; no single of choice for ground fault interruption phasing on tripping when air interrupters alone would be potentially hazardous if called on to ■ Maintainable operate above their assigned ratings. ■ Long equipment life Capacitor switching is easily handled ■ Special applications, such as capacitor by MSB and avoids the restrike hazard switching, are possible with breakers presented by air switches. Standardized designs cover most common applications, while custom designs are also available for custom requirements. 5/15 kV MSB Assembly EATON www.eaton.com Metal-Enclosed Switchgear, MSB Design Guide DG022010EN Utilizing Medium-Voltage Switch and Vacuum Breakers Effective February 2020 General Description 7.2-3 Construction Eaton’s Power Xpert and IQ family of Eaton’s Type MSB switchgear uses the electronic meters is normally used when same proven enclosure and air switch metering functions are required. mechanism as MVS switchgear. It differs The circuit breaker is bolted into position, by using the fixed-mounted Eaton VCP-TR but can be unbolted and removed from (5–15 kV) vacuum breaker in place of the enclosure. Routine maintenance can fuses. Current transformers associated be performed on the circuit breaker with protection devices such as the mechanism in the enclosure. EDR-3000 or EDR-5000 electronic protective relays are applied using the Standard switch insulators are NEMA same ratings as drawout metal-clad rated glass polyester or optional epoxy. switchgear. Integral overcurrent Control power will be required as detailed protective devices with the Arcflash below. AC can be supplied integrally if Reduction Maintenance System™ such specified.DC control power, if required, as DT 520MCV and DT-1150V trip units must be furnished by others. are also available. Devices are mounted If AC control power is used, a capacitor on the single front-hinged door. The trip device is provided. front door may be opened at any time to provide access to low-voltage Once the circuit breaker is closed and components and the front of the circuit the closing spring is recharged, the breaker without being exposed to breaker can open, close and open medium voltage. without spring recharge. MSB with Control Switches, Digitrip 3000® Overcurrent Relay with Optional Metering Shown Standard MSB Switchgear and Assembly Ratings Table 7.2-1. MSB Switchgear Assembly Ratings Rated Maximum Rated Rated Main Bus Rated Momentary Rated Short-TIme Volts kV BIL kV Current Amperes Current kA rms (2 Seconds) Asymmetrical Current kA Symmetrical 4.76 60 600, 1200, 2000 40 25 4.76 60 600, 1200, 2000 64 40 15 95 600, 1200 40 25 15 95 600, 1200 64 40 EATON www.eaton.com Metal-Enclosed Switchgear, MSB Design Guide DG022010EN Utilizing Medium-Voltage Switch and Vacuum Breakers Effective February 2020 Devices 7.2-4 Circuit Breakers Circuit Breaker Ratings Type MSB assemblies can be supplied with Type VCP-TR (stored energy operator) or with Type VCP-TRL (electro-magnetic linear actuator operator) circuit breakers. Refer to Table 7.2-3 for additional capacitor switching capability of the VCP-TR and VCP-TRL circuit breakers. Table 7.2-2. Available Type VCP-TR and VCP-TRL Vacuum Circuit Breakers Rated per ANSI Standards (C37.04, C37.06, C37.09) Circuit Rated Insulation Level Rated Rated Rated Maximum Closing and Cable Three- Mechanical Breaker Max. Power Impulse Continuous Short- Voltage Symmetrical Latching Charging Phase Endurance ab Type Voltage Frequency Withstand Current Circuit Range Interrupting Capability Breaking MVA at No Load C-O Withstand Voltage Current Factor & 2-Second (Momentary) Current Rated Operations Voltage (BIL) at Rated Short-Time Maximum 60 Hz, 1.2 x 50 Maximum Current Voltage 1 Minute microsec Voltage Carrying (for Capability Reference Only) V I K K * I 2.6 * K * I 1.732 * V * I kV rms kV rms kV Peak Amperes kA rms kA rms kA Crest Amperes MVA Vacuum Mechanism sym sym Interrupter 50 VCP-TR 25 4.76 19 60 600, 1200 25 1 25 65 10 210 30,000 10,000 50 VCP-TRL 25 4.76 19 60 600, 1200 25 1 25 65 10 210 30,000 100,000 50 VCP-TR 40 4.76 19 60 600, 1200 40 1 40 104 10 330 30,000 10,000 150 VCP-TR 25 15 36 95 600, 1200 25 1 25 65 25 650 30,000 10,000 150 VCP-TRL 25 15 36 95 600, 1200 25 1 25 65 25 650 30,000 100,000 150 VCP-TR 40 15 36 95 600, 1200 40 1 40 104 25 1040 30,000 10,000 a Rated interrupting time for all VCP-T circuit breakers is 3 cycle (50 ms). b Operating duty for all VCP-T circuit breakers is O-0.3sec-CO-3min-CO. Table 7.2-3. Capacitor Switching Capability of Type VCP-TR and VCP-TRL Circuit Breakers Circuit Rated Cable Isolated Shunt Back to Back Capacitor Switching Breaker Continuous Charging Capacitor Capacitor Inrush Inrush Type Current Current Bank Current Bank Current Current Frequency A A A A kA peak kHz 50 VCP-TR 25 600, 1200 10 — — — — 50 VCP-TRL 25 600, 1200 10 250 and 630 250 15 5.0 630 15 1.5 50 VCP-TR 40 600 10 75–400 75–400 18 2.4 1200 10 75–630 75-630 18 2.4 150 VCP-TR 25 600, 1200 25 — — — — 150 VCP-TRL 25 600, 1200 25 250 and 630 250 15 5.0 630 15 1.5 150 VCP-TR 40 600 25 75–400 75–400 18 2.4 1200 25 75–630 75–630 18 2.4 Note: Type VCP-TRL 25 and VCP-TR 40 circuit breakers shown in this table are considered definite-purpose breakers per ANSI C37.04. Breaker Control Ratings Table 7.2-4. Breaker Stored Energy Mechanism Control Power Requirements Rated Spring Charge Motor b Close or Trip Voltage Range Control Amperes Voltage Run Time Close Tri p Amperes Seconds 48 Vdc 4.0 5 5.2 38–56 28–56 125 Vdc 3.0 5 3.6 100–140 70–140 250 Vdc 2.0 5 1.8 200–280 140–180 120 Vac 3.0 5 3.6 104–127 104–127 240 Vac 2.0 5 1.8 208–254 208–254 c Inrush current is 4 times running amperes.