— PRODUC T I N FOR M ATI ON

Dead Tank Circuit Breaker with Metal Oxide Varistors Shunt reactor switching protection

Switching a reactor causes fast front transient recovery voltages across the circuit breaker, challenging the endurance of the breaker and reliability of the transmission system.

A reactor is put into service to absorb reactive power and prevent the transmission line voltage from exceeding its design value.

In close cooperation with its customers, ABB has developed a unique, innovative and patented or patent pending Dead Tank Circuit Breaker solution - utilizing integrated Metal Oxide Varistors (MOV) - that exceeds current standard requirements for this highly variable and demanding switching application.

Why an Metal Oxide Varistor (MOV)?MOV is designed as a fast-acting long-life voltage limiter for high energy applications with excellent low level protection characteristics. These characteristics make it an excellent choice to limit the damaging over voltages associated with reactor switching.

The MOV can be applied externally across the bushings or internally across the interrupter breaking chambers. In either installation, the MOV acts to reduce the probability of re-ignition and limit the over voltages associated with reactor de-energization switching. MOV internal installation has the added advantage of lessening the stress on the internal grading capacitors in case of multi-break design interrupter.

Benefits of an applied MOV• System reliability• Protection of reactor and circuit breaker• No additional footprint requirements• Retrofit options available on existing installations• Lower total ownership cost

—01 MOV across the breaker bushings

For 245 kV• MOV mounted across the bushings of the same

phase • Limits over voltage across the open interrupter

breaker contacts • Retrofitable solution for existing installations • EXCOUNT surge counters can add extra level of

awareness

DTB with MOV across the pole

DTB with internal MOV

DTB with freestanding MOV

For 550 kV• Freestanding MOV module • Limits over voltage across the open interrupter

breaker contacts• Retrofitable solution for existing installations• EXCOUNT surge counters can add extra level of

awareness

For 362 kV, 550 kV and 800 kV• Mounted across interrupter (similar to internal

grading capacitor)• Limits transient voltage across breaking chambers

during switching events • Proven and tested internal installation

0 5 10 15 20 25 30 35

1

2

3

Years

Op

erat

ions

per

yea

r

Number of overhauls over 30 year life

Overhaul per 30 year life - With MOV Overhaul per 30 year life - No MOV

Twice as many operations for M1 breaker with MOV and five times more operations for M2 breaker with MOV, with reduced life cycle cost and risk.

1 Based on circuit breaker rated M2.

0

1000

2000

3000

4000

5000

6000

With no MOV and no syncopening

With MOV - M1 ratedbreaker

With MOV - M2 ratedbreaker

Number of operations before interrupter inspection / overhaul

Life cycle comparison

1

More than 80% reduction in overhauls and reduces life cycle cost and risk.

Technical details - Internal MOV 362 kV, 80 kA 550 kV, 63 kA 800 kV, 63 kA

Maximum voltage

362 kVrms (L-L)220 kVrms (Max L-G voltage in

open position limited by MCOV rating)

550 kVrms (L-L)320 kVrms (Max L-G voltage in

open position limited by MCOV rating)

800 kVrms (L-L)480 kVrms (Max L-G voltage in

open position limited by MCOV rating)

Rated insulation level: Power frequency withstand voltage

555 kVrms -- closed position220 kVrms -- open position

860 kVrms -- closed position320 kVrms -- open position

960 kVrms -- closed position480 kVrms -- open position

Mechanical class M2 (10,000 operations) M2 (10,000 operations) M2 (10,000 operations)

Rated shunt reactor switching current 100 - 300 A 100 - 300 A 120 A

MOVInternal across breaking unit:

110 kV MCOV / chamberInternal across breaking unit:

160 kV MCOV / chamberInternal across breaking unit:

160 kV MCOV / chamber

Number of MOV’s per pole 2 2 (for 63 kA) / 3 (for 80 kA) 3

Nominal discharge current In: 10 kA @ 8 / 20 μs 10 kA @ 8 / 20 μs 10 kA @ 8 / 20 μs

MOV class according to IEC 60099-4 Ed. 3.0 Class 3 Class 3 Class 3

Classification according to IEEE C62.11 Station Class Station Class Station Class

Rated thermal energy Wth

≥ 7 kJ / kV (Ur) @ Tamb = 40° C≥ 6 kJ / kV (Ur) @ Tamb = 65° C

≥ 7 kJ / kV (Ur) @ Tamb = 40° C≥ 6 kJ / kV (Ur) @ Tamb = 65° C

≥ 7 kJ / kV (Ur) @ Tamb = 40° C≥ 6 kJ / kV (Ur) @ Tamb = 65° C

Technical details - External MOV 245 kV, 63/80 kA

Maximum voltage

245 kVrms (L-L)144 kVrms (Max L-G voltage in

open position limited by MCOV rating)

Rated insulation level: Power frequency withstand voltage

425 / 460 kVrms -- closed144 kVrms -- open

Mechanical class M1 (2,000 operations)

Rated shunt reactor switching current 100 - 300 A

MOVExternal mounted:

144 kV MCOV

Number of MOV’s per pole 1

Nominal discharge current In: 10 kA @ 8 / 20 μs

MOV class according to IEC 60099-4 Ed. 3.0 Class 3

Classification according to IEEE C62.11 Station Class

Rated thermal energy Wth ≥ 7.8 kJ / kV (Ur)

—We reserve the right to make technical changes or modify the contents of this document without prior notice. With regard to purchase orders, the agreed particulars shall prevail. ABB Inc. does not accept any responsibility whatsoever for potential errors or possible lack of information in this document.

We reserve all rights in this document and in the subject matter and illustrations contained therein. Any reproduction, disclosure to third parties or utilization of its contents – in whole or in parts – is forbidden without prior written consent of ABB Inc. Copyright© 2017 ABBAll rights reserved

—ABB, Inc.Dead Tank Circuit Breakers100 Distribution CircleMt. Pleasant, PA 15666Phone: +1 724-696-1500

abb.com/highvoltage 2GN

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Patent informationUS 9,728,362Other patents pending