Product Core Overview

PowlVac ®  Series 4 vacuum circuit breaker is a new generation of metal armored vacuum circuit breaker launched by Powell Industries in the United States, suitable for medium and high voltage power systems ranging from 5kV to 38kV. Its design originated from the first PowlVac circuit breaker in 1982 and has been upgraded and optimized for multiple generations, combining compactness, high reliability, and low maintenance. The product focuses on ‘Powered by Safety’ ®”  The concept provides multiple customized options (such as narrow body design, manual/automatic rack and pinion transmission, intelligent monitoring equipment), which can adapt to the space limitations of existing equipment and meet the protection needs of medium and high voltage circuits in industrial, power and other fields.

Core design upgrade and features

（1） Key design upgrade

As a new generation product, Series 4 has undergone multiple optimizations in structure, compatibility, and maintainability, with the following core upgrade points:

Optimization of primary side disconnect components: Upgrade the primary side disconnect components of all 36 inch frame circuit breakers, improve the alignment tolerance between the circuit breaker and the cabinet installation pin components, and reduce installation difficulty; The contact components and circuit breaker pin components can be separated for easy maintenance and replacement, reducing downtime.

Universalization of secondary control wiring harness: For each type of circuit breaker frame size and rated value, the secondary control wiring harness is designed uniformly to simplify spare parts management and maintenance replacement processes.

32 pin secondary disconnect component upgrade: All Series 4 circuit breakers come standard with a 32 pin secondary disconnect component, which is designed for each frame size and includes Powell CBM ® Wiring of all control options for the Circuit Breaker Monitor device; Four pins are reserved for future communication function expansion.

Support integration of intelligent monitoring devices: All Series 4 frameworks and wiring harnesses are designed to be able to install CBM in the factory or on-site later ® (Circuit breaker monitor), without the need for large-scale renovation, enhances equipment intelligence and status monitoring capabilities.

Backward compatibility: Through minor modification, it can be compatible with the old PowlVac ®  Circuit breakers are completely interchangeable, reducing the cost of upgrading existing systems.

（2） Core functional characteristics

Compact design: Provides narrow body (PowlVac ND) ®） Model, meets the requirement of “reducing footprint” and adapts to the space limitations of existing equipment.

Rack Drive Options: All Series 4 circuit breakers can be optionally equipped with “onboard rack drive”, supporting both manual and automatic transmission modes to enhance operational convenience.

High durability: Short circuit breaking current rating coefficient K=1.0 (constant breaking rating), tested to achieve 10000 operations, with a long service life.

Low maintenance current transmission: Optimization of current transmission component design to reduce maintenance requirements and lower operation and maintenance costs.

Short term tolerance: With a 2-second short-term tolerance, it can withstand the impact of short-term short-circuit current and ensure system stability.

Detailed technical parameters (voltage level and rated value)

PowlVac ®  Series 4 circuit breakers are classified into voltage levels such as 5kV, 15kV, 27kV, 29.8kV, 38kV, etc. Different categories correspond to different frame sizes, short-circuit ratings, and continuous current ratings. The specific parameters are shown in the table below (“・” indicates that this specification supports corresponding continuous current):

Voltage level (kV) Product model Cabinet width (inches) Short circuit rating (kA) Lightning impulse withstand voltage (BIL, kV) Power frequency withstand voltage (kV) Continuous current rating (A)

1200A 2000A 3000A 5000A²

5kV PowlVac-ND ®  26 36 60 19 • • – –

5kV PowlVac-ND ®  26 50 60 19 • • – –

5kV PowlVac ®  36 36 60 19 • • • –

5kV PowlVac ®  36 50 60 19 • • • –

5kV PowlVac ®  36 63 60 19 • • • –

15kV PowlVac ®  36 25 95 36 • • • –

15kV PowlVac ®  36 36 95 36 • • • –

15kV PowlVac ®  36 50 95 36 • • • –

15kV PowlVac ®  36 63 95 36 • • • –

15kV PowlVac ®  36 63G¹ 95 36 • • • –

15kV PowlVac ®  36 48 63G¹ 95 36 – – •

27kV PowlVac-ND ®  36 25 125 60 • • – –

29.8kV PowlVac-ND ®  36 25 125 60 • • – –

27kV PowlVac ®  40 25 125 60 • • – –

27kV PowlVac ®  40 40 125 60 • • – –

38kV PowlVac ®  40 25 150 80 • • – –

38kV PowlVac ®  40 40 150 80 • • – –

38kV PowlVac ®  54 40 150 80 – – • –

Note: 1 63G represents the rated circuit breaker of the generator that meets the C37.013 standard test; 2. The 5000A circuit breaker is suitable for fixed metal enclosed applications and requires an isolation switch.