SIEBREAK and SIEBREAK-VCB non-arc-resistant, air-insulated, metal-enclosed interrupter switchgear

5-15 kV
  • Rated short-time current up to 38 rms kA

  • Rated continuous current up to 1,200 A

  • Lightning impulse (BIL) up to 95 kV

Air-insulated, medium-voltage, non-arc-resistant, metal-enclosed interrupter switchgear, type SIEBREAK

Siemens SIEBREAKTM metal-enclosed interrupter switchgear design is a modular product available in switch and fuses configuration assembled and fully integrated both mechanically and electrically to provide medium-voltage circuit protection. All components are fully tested to perform in accordance with Siemens' standards for reliability, quality, and service.

 

SIEBREAK switchgear is available in both fused and unfused configurations. Supplied in the unfused configuration, short-circuit protection is not available - only load-current interruption. Supplied fused or unfused, a load-interrupter switch is different from a vacuum circuit breaker in that it will interrupt load current, but not overload or fault currents.

Fused switches are available with current-limiting or expulsion (power) fuses. Fuses extend the range of applications up to the maximum ratings of the fuse, as much as 50 kA for current-limiting fuses.

 

A complete product line for various distribution applications:

  • Standalone bay

  • Transformer primary

  • Lineups (i.e., main-tie-main, main feeders, automatic transfer).

Air-insulated, medium-voltage, non-arc-resistant, metal-enclosed interrupter switchgear, type SIEBREAK

Features

Features include:

  • 5 kV and 15 kV voltage rated classes

  • 600 A and 1,200 A continuous current

  • Non-fused or fused with current-limiting or expulsion (power) fuses

  • Indoor type 1 enclosure

  • Single, duplex, and selector switch types

  • Large 8" x 18" (203 mm x 457 mm) viewing window

  • Hinged, grounded, metal barrier in front of switch blades

  • 11-gauge doors, covers, and barriers

  • Silver-plated copper bus bar

  • Full-length ground bus

  • ANSI 61 (grey) paint

  • Phase barriers

  • Provisions for key interlock

  • Mechanical door and switch interlock

  • Ventilation louvers in top and bottom, front and rear

  • Glass-polyester bus supports

  • Non-corrosive nameplate

  • Switch padlock provisions

  • Standard arrangements with automatic-transfer control systems

  • Space heater (half-voltage) with thermostat (optional)

  • NEMA hole patterns for cable termination.

Modular configurations:

  • Surge arresters

  • Instrument transformers  - current transformers (CTs) or voltage transformers (VTs)

  • Control power transformer (CPT)

  • Power meter

  • Other auxiliary equipment.

Standard outdoor features:

  • Bottom cable-entry cover plate

  • Removable filters

  • 6" (152 mm) formed steel base

  • Outdoor NEMA 3R enclosure.

Optional:

  • UL and C-UL listings

  • Indoor type 2 drip-proof enclosure

  • Indoor type 12 dust-resistant enclosure

  • Tin-plated copper bus bars

  • Motor-operated mechanism

  • High-track resistance bus support

  • Auxiliary switches (2 NO-2 NC)

  • Mimic bus

  • Ground studs

  • Screens and filters (indoor)

  • Special paint color
  • Channel sills.

Construction, standards, and switch types

Construction

SIEBREAK metal-enclosed interrupter switchgear enclosure is of metal-enclosed construction as described in ANSI/IEEE standards. The equipment is tested and factory assembled into convenient shipping groups. It is ruggedly constructed of 11-gauge sheet steel including the doors. The assembly employs bolted construction. SIEBREAK's modular design is available in many different enclosure types and bus configurations. The switch mechanism is arranged in the upper portion of the enclosure while the fuses are located in the lower portion. Switch and fuses are arranged for ease of operation and inspection. A large viewing window is standard for observing the position of the switch blades when the door is closed. The front door and switch operating mechanism are interlocked to prohibit access to the switch compartment when the switch is closed and prohibit operating the switch operating mechanism when the door is open.

 

Standards

SIEBREAK metal-enclosed switchgear meets or exceeds the requirements of the following standards:

  • ANSI/IEEE C37.20.3
  • ANSI/IEEE C37.20.4
  • ANSI C37.57
  • ANSI C37.58
  • CSA 22.2 No. 31 (for Canada)
  • CSA 22.2 No. 58 (for Canada)
  • CSA 22.2 No 193 (for Canada).

SIEBREAK switchgear assemblies can optionally be listed with UL and, for use in Canada, have C-UL listing certifying compliance with Canadian standards and codes.

 

SIEBREAK arrangement identification
Item
Description
1
Panel
2
Vent
3
Viewing window
4
Operating switch handle
5
Quarter-turn door fastener
6
Lifting eyes
7
Low-voltage panel

A complete line of switch types: single, duplex, and selector.

Single-source application: Single (left in image)

Single vertical section equipped with one 600 A or 1,200 A load-interrupter switch rated up to 15 kV with cable incoming-line termination and load-cable termination. Cable direction for incoming and outgoing cable entry either top or bottom with an option for close-coupled line or load connection to dry- or liquid-filled type transformer.

 

Dual-dource application: Duplex (center in image)

Two close-coupled vertical sections each equipped with one 600 A or 1,200 A load-interrupter switch rated up to 15 kV. Incoming and outgoing cable direction for either top or bottom cable entry with an option for close-coupled load connection to dry- or  liquid-filled type transformer.

 

Dual-source application: Selector (right in image)

Single vertical section equipped with one 600 A load-interrupter switch rated up to 15 kV and one 600 A non-load-interrupting, two-position selector switch for selective source capability. Cable direction for incoming and outgoing cable entry either top or bottom with an option for close-coupled load connection to dry- or liquid-filled type transformer.

 

 

SIEBREAK switch types indentification
Item
Description
A
600 A or 1,200 A interrupter switch
B
Fuses
C
600 A non-load-break selector switch
D
600 A interrupter switch

Ratings

Maximum design voltage kV
Impulse-withstand voltage kV BIL
Continuous current for main bus A
Momentary  rms kA (fused)1
Rated short-time current (two seconds) unfused
5.0
60
600
39
25
5.0
60
600
59
38
5.0
60
1,200
39
25
5.0
60
1,200
59
38
15.0
95
600
39
25
15.0
95
600
59
38
15.0
95
1,200
39
25
15.0
95
1,200
59
38

Dimensions

SIEBREAK standard configuration
Single
Duplex
Selector
Lineup
Types 1, 2, 12, and 3R enclosures
*
*
*
*
36” (914 mm) wide types 1, 2, 12, and 3R
*
 
*
 
72” (1,829 mm) wide
 
*
 
 
60” (1,524 mm) wide for front-access design
*
 
 
*
2.62” (67 mm) width transition to dry-type transformer for type 3R outdoor
*
*
*
 
18” (457 mm) width transition to liquid-filled transformer
*
*
*
 
92” (2,337 mm) height types 1 and 12 enclosures
*
*
*
*
105” (2,667 mm) height type 3R enclosure
*
*
*
*
99” (2,515 mm) height type 2 enclosure
*
*
*
*
62” (1,575 mm) depth standard for type 1 enclosure
*
 
 
*
72” (1,829 mm) depth standard for type 1 enclosure
 
*
*
 
72” (1,829 mm) depth for standard for types 2, 12, and 3R enclosure (optional)
*
*
*
*
56” (1,422 mm) depth for front-access design
*

 
 
*

TechTopics is a series of papers that discuss issues of interest to users or specifiers of electrical equipment.

Air-insulated, medium-voltage, non-arc-resistant, switch and circuit breaker combination metal-enclosed interrupter switchgear, type SIEBREAK-VCB

Siemens SIEBREAK-VCBTM metal-enclosed interrupter switchgear design is a modular product available in switch and fixed-mounted vacuum circuit breaker configuration assembled and fully integrated both mechanically and electrically to provide medium-voltage circuit protection. All components are fully tested to perform in accordance with Siemens' standards for reliability, quality, and service.

 

Siemens SIEBREAK-VCB metal-enclosed switch and circuit breaker combination is modular assembly consisting of a load-interrupter switch mechanism connected in series with a Siemens fixed-mounted vacuum circuit breaker to provide a safe, cost effective, reliable, and flexible solution for use in standalone, low-voltage substations transformer primary, and lineup configurations. Visible disconnect is provided by the load-interrupter switch and protection is provided by the fixed-mounted vacuum circuit breaker

 

A complete product line for various distribution applications:

  • Standalone bay
  • Transformer primary
  • Lineups (i.e., main-tie-main, main feeders, automatic transfer).

A complete line of switch types:

  • Single switch
  • Duplex switch.

Air-insulated, medium-voltage, non-arc-resistant, switch and circuit breaker combination, metal-enclosed interrupter switchgear

Features

Features include:

  • 5 kV and 15 kV voltage classes
  • 600 A and 1,200 A continuous current

  • Siemens overcurrent protection relay

  • Indoor type 1 enclosure

  • Single and duplex switch types

  • Large 8” x 18” (203 mm x 457 mm) viewing window

  • Hinged, grounded metal barrier in front of switch blades

  • 11-gauge doors, covers, and barriers

  • Silver-plated copper bust

  • Provisions for key interlocking

  • Mechanical door and switch interlock

  • Upper and lower ventilation louvers

  • Glass-polyester bus supports

  • Non-corrosive nameplate

  • Space heater with thermostat (optional)

  • NEMA CC1 hole patterns for cable termination

  • Current transformers (CTs) - one per phase.

Modular configurations:

  • Surge arresters
  • Instrument transformers  - current transformers (CTs) or voltage transformers (VTs)
  • Control power transformer (CPT)
  • Power meter.

Standard outdoor features:

  • Long-life space heaters (half-voltage)
  • Bottom cover plate

  • Externally removable filters

  • 6” (152 mm) formed steel base.

Optional:

  • UL or C-UL Listing
  • Indoor type 2 drip-proof enclosure

  • Indoor type 12 dust-resistant enclosure

  • Outdoor non-walk-in type 3R enclosure

  • High-track resistance bus supports

  • Auxiliary switches (2 NO-2 NC)

  • Mimic bus

  • Ground studs (ball stud) type

  • Screens and filters (indoor)

  • Tin-plated copper bus

  • Second set of current transformers.

Construction, standards, and switch types

Construction

SIEBREAK-VCB metal-enclosed interrupter switchgear enclosure is of metal-enclosed construction as described in ANSI/IEEE standards. The equipment is tested and factory assembled into convenient shipping groups. It is ruggedly constructed of 11-gauge sheet steel including the doors. The assembly employs bolted construction. SIEBREAK-VCB's modular design is available in many different enclosure types and bus configurations. The switch mechanism is arranged in the upper portion of the enclosure while the fuses or fixed-mounted circuit breaker are located in the lower portion. Switch and fuses or fixed-mounted circuit breaker are arranged for ease of operation and inspection. A large viewing window is standard for observing the position of the switch blades when the door is closed. The front door and switch operating mechanism are interlocked to prohibit access to the switch compartment when the switch is closed and prohibit operating the switch operating mechanism when the door is open.

 

Standards

SIEBREAK-VCB metal-enclosed switchgear meets or exceeds the requirements of the following standards:

  • ANSI/IEEE C37.20.3
  • ANSI/IEEE C37.20.4
  • ANSI/IEEE C37.04

  • ANSI/IEEE C37.09

  • ANSI C37.54.

  • ANSI C37.57
  • ANSI C37.58
  • CSA 22.2 No. 31 (for Canada)
  • CSA 22.2 No. 58 (for Canada)
  • CSA 22.2 No 193 (for Canada).

SIEBREAK-VCB switchgear assemblies can optionally be listed with UL and, for use in Canada, have C-UL listing certifying compliance with Canadian standards and codes.

 

SIEBREAK-VCB arrangement identification
Item
Description
1
Panel
2
Vent
3
Viewing window
4
Operating switch handle
5
Quarter-turn door fastener
6
Lifting eyes
7
Low-voltage panel
8
Low-voltage compartment

A complete line of switch types: single, duplex, and selector.

Single-source application: Single switch and circuit breaker (left in image)

Single vertical section equipped with one 600 A or 1,200 A load-interrupter switch and fixed-mounted vacuum circuit breaker rated up to 15 kV with cable incoming-line termination and load-cable termination. Cable direction for incoming and outgoing cable entry either top or bottom with an option for close-coupled line or load connection to dry or liquid-filled type transformer.

 

Dual-dource application: Duplex (right in image)

Two close-coupled vertical sections each equipped with one 600 A or 1,200 A load-interrupter interrupter switch and a common bus connection to a fixed-mounted vacuum circuit breaker rated up to 15 kV. Incoming and outgoing cable direction for either top or bottom cable entry with an option for close-coupled load connection to dry- or liquid-filled type transformer.

 

 

SIEBREAK-VCB switch types indentification
Item
Description
A
600 A or 1,200 A interrupter switch
B
Fixed-mounted circuit breaker

Reducing the arc-flash incident energy in low-voltage substation applications with SIEBREAK-VCB™ metal-enclosed interrupter switchgear with OMARS

Arc-flash mitigation is at the forefront today

NFPA 70E Standard for Electrical Safety in the Workplace® has increased the emphasis for greater measures for reducing arc-flash hazards in the secondary bus protection in the substation. Siemens SIEBREAK-VCB with operation and maintenance arc-flash reduction system (OMARS) offers a practical approach to providing both primary and secondary bus protection to reduce the incident energy associated with an arcing fault on the line side of the low-voltage

main circuit breaker, or on the low-voltage main bus if there is no low-voltage main circuit breaker.

 

The right solution to arc-flash hazard

SIEBREAK-VCB with OMARS solves the arc-flash safety hazard situation present in many existing installed substations in operation today with the traditional fused load-interrupter switch.

 

The fused primary load-interrupter switch in the existing substations can be replaced with SIEBREAK-VCB with OMARS to reduce the arc-flash hazard.

 

Configuration

Current transformers or sensors and protective relays can be installed in the low-voltage switchgear or switchboard for

input into SIEBREAK-VCB circuit protection system. In this configuration, the bus protection will be provided on the both the primary and secondary bus to reduce the arc-flash incident energy on the secondary.

 

Three ways for reducing the arc-fault incident energy

SIEBREAK-VCB is available in three advanced ways for reducing the incident arc-fault energy on the secondary bus of substation:

  • Relay maintenance mode setting
  • Fiber optics arc-flash detection system
  • Short-circuit relay protection on the secondary bus.

Double-ended substation arrangement features and options

SIEBREAK-VCB applied in a double-ended substation arrangement offers several optional features including:

  • Short-circuit protection on the secondary side of each transformer (secondary bus in the low-voltage equipment)
  • Increased reliability and protection with redundancy between the protective relays located in each SIEBREAK unit
  • Power metering with voltage transformer installed in SIEBREAK or the secondary equipment
  • Transformer differential relay (87T) protection for enhanced system and transformer protection
  • Arc-flash detection fiber for increased the safety against arc flash can be installed throughout the low-voltage equipment.

SIEBREAK-VCB configuration in low-voltage or medium-voltage substations

Reduction of arc-flash incident energy

For the configurations where SIEBREAK-VCB is used as the transformer primary for the low-voltage substation that is

configured with the arc-flash reduction technology, the incident energy can be reduced to as low as 2.1 cal/cm2 with an

interrupting time of 60 ms.

 

By contrast, for the scenario where the traditional fused load-interrupter switch is used as the transformer primary for the low-voltage substation, the incident energy can be as high 38.3 cal/cm2 (or even higher) with an interrupting time of 900 ms.

 

SIEBREAK-VCB is available in four advanced configurations for reducing the incident arc-fault energy on the secondary bus of substation:

 

SIEBREAK-VCB four advanced configurations
Components
Low-voltage circuit breaker configuration #1
Low-voltage circuit breaker configuration #3
Virtual main configuration #2
Virtual main configuration #4
Siemens 7UT8 protective relay
Standard
Standard
Standard
Standard
Siemens 7UT8 protective relay with arc-flash module
Optional
Optional
Optional
Optional
Siemens 7SJ82 protective relay
Optional
Optional
Optional
Optional
Siemens 7SJ82 protective relay with arc-flash module
Optional
Optional
Optional
Optional

Configurations #1 and #3: Low-voltage circuit breaker configurations 

SIEBREAK-VCB equipped with a Siemens 7UT8 transformer differential protective relay along with an additional set of current transformers located in the auxiliary compartment of the low-voltage equipment provides a reliable system for reducing the incident energy on the secondary bus thus reducing the arc-flash hazard in this area. Optionally, the protective relay can be equipped with an arc-flash detection module for additional arc-flash protection and mitigation.

 

Configurations #2 and #4: Virtual main configuration

Same as configurations #1 and #3 except the low-voltage equipment is installed remote from the SIEBREAK-VCB panel. The current transformers in the low-voltage auxiliary compartment will be hardwired directly to the 7UT8 protective relay in the SIEBREAK-VCB panel. The type Siemens7SJ82 protective relay located in the low-voltage switchgear or switchboard is used primarily for the optional arc-flash detection system to transfer the trip signal to the 7UT8 protective relay. For this option, the 7SJ82 protective relay connection is hardwired or fiber-optic cable connected to the 7UT8 protective relay located in the SIEBBREAK-VCB panel. The type or connection is depended upon the customer‘s preference to run hardwires or fiber-optic cables. In most cases, the decision on whether to use hardwire or fiber optic is based on various factors. Please consult factory. 

SIEBREAK-VCB with OMARS configurations identification
Item 
Description
A
SIEBREAK-VCB with OMARS
B
Fuses
C
Optional control power transformer
D
Secondary circuit breaker
E
Load-interrupter switch
F
Phase current transformers
G
7UT8 protective relay
H
600 A or 1,200 A fixed-mounted vacuum circuit breaker
I
Unit substation transformer
J
Optional voltage transformers
K
Low-voltage main circuit breaker
L
Optional arc-detection fiber
M
Low-voltage switchboard or switchgear
N
7SJ82 protective relay

Ratings

 

SIEBREAK switchgear assembly ratings

Maximum design voltage kV
Dielectric withstand voltage - power frequency kV rms
Dielectric withstand voltage - impulse kV peak
Continuous current for main bus A
Short-circuit current unfused kA sym
Fault-closing current unfused symmetrical kA rms
5.0
19
60

600

1,200

2,000

25

38

39

59

15.0
36
95

600

1,200

2,000

25

38

39

59

Type SBVCB vacuum circuit breaker ratings

Maximum design voltage kV
Dielectric withstand voltage - power frequency kV rms
Dielectric withstand voltage - impulse kV peak
Continuous current for main bus A
Short-circuit current unfused kA sym
Circuit breaker type
Closing and latching current kA sym
Closing and latching current kA rms
5.0
19
60

600

1,200

25

38

05-SBVCB-25-0600-65

05-SBVCB-25-1200-65

05-SBVCB-40-0600-104

05-SBVCB-40-1200-104

25

40

39

59

15.0
36
95

600

1,200

25

38

15-SBVCB-25-0600-65

15-SBVCB-25-1200-65

15-SBVCB-40-0600-104

15-SBVCB-40-1200-104

25

40

39

59

Dimensions

SIEBREAK standard configuration
Single
Duplex
Lineup
Types 1, 2, 12, and 3R enclosures
*
*
*
36” (914 mm) wide types 1, 2, 12, and 3R
*
 
 
72” (1,829 mm) wide
 
*
 
60” (1,524 mm) wide for front-access design
*
 
*
2.62” (67 mm) width transition to dry-type transformer for type 3R outdoor
*
*
 
18” (457 mm) width transition to liquid-filled transformer
*
*
 
92” (2,337 mm) height types 1 and 12 enclosures
*
*
*
105” (2,667 mm) height type 3R enclosure
*
*
*
62” (1,575 mm) depth standard for type 1 enclosure
*
 
 
72” (1,829 mm) depth for standard for types 1, 2, 12, and 3R enclosures (optional)
*
*
*
56” (1,422 mm) depth for front-access design
*

 
*

TechTopics is a series of papers that discuss issues of interest to users or specifiers of electrical equipment.