| 1 | Drawout ACB with Electronic Trip Unit | Main low-voltage switchboards, data centers, industrial plants, and critical distribution systems requiring fast maintenance and isolation. | 3-pole or 4-pole; neutral pole may be switched or unswitched depending on the system design. | Commonly 630–6,300 A; confirm the frame and continuous-current rating. | Often offered from approximately 42 kA to 100 kA at 415–690 V, subject to the exact model and test duty. | Overload, short-time, instantaneous, and ground-fault protection; service, test, and disconnected positions; mechanical interlock; shunt trip; undervoltage release; auxiliary contacts; communication modules. | IEC 60947-2EN 60947-2IEC 60947-1UL 1066 where applicable | Valid type-test evidence for the exact frame and trip unit; rated service short-circuit capacity; temperature-rise data; dielectric test data; routine-test records; destination-market conformity documentation. | Check cradle compatibility, spare drawout mechanism availability, coding/keying options, delivery of trip units, and whether accessories are factory-installed or supplied separately. | Incorrect cradle or accessory matching; lower interrupting rating at the required voltage; unavailable replacement trip unit; unverified communication protocol; excessive lead time for drawout parts. |
| 2 | Fixed-Mounted ACB with Electronic Trip Unit | Cost-sensitive main incomers, feeders, generator outputs, and installations where frequent breaker removal is not required. | 3-pole or 4-pole. | Commonly 630–6,300 A. | Frequently available in approximately 42–100 kA classes, depending on voltage, frame size, and test standard. | Adjustable long-time, short-time, instantaneous, and earth-fault settings; local indication; remote trip and alarm contacts; optional metering and communication. | IEC 60947-2EN 60947-2IEC 60947-1GB/T 14048.2 for China-market conformity | Request the complete rating plate, routine-test certificate, type-test report, internal arc or assembly evidence where relevant, and declaration of conformity for the import market. | Verify mounting dimensions, terminal orientation, busbar connection method, control-voltage range, protection setting access, and availability of compatible spare accessories. | Lower purchase price may hide higher installation downtime; fixed mounting can complicate maintenance; dimensional mismatch may require switchboard redesign. |
| 3 | Four-Pole ACB with Switched Neutral | Systems with separate neutral switching requirements, multiple sources, generator transfer schemes, and installations where neutral potential must be isolated. | 4-pole with the neutral pole switched by the mechanism. | Commonly 630–6,300 A; neutral rating may be full-size or reduced according to design. | Depends on the base ACB; commonly approximately 42–100 kA at the stated operating voltage. | Simultaneous pole operation; selectable neutral pole position; adjustable protection; source transfer interlocking; auxiliary contacts and shunt/undervoltage releases. | IEC 60947-2IEC 60947-6-1 for transfer equipment interfacesIEC 60364 installation rules | Confirm four-pole type-test coverage, neutral-pole making and breaking capability, switching sequence, short-circuit performance, and control-circuit test results. | Confirm whether the neutral pole is fully rated, leading, lagging, or simultaneous; verify neutral terminal size and compatibility with the system earthing arrangement. | Incorrect neutral switching sequence; unsuitable application in solidly bonded systems; reduced neutral capacity; confusion between switched-neutral and solid-neutral versions. |
| 4 | Three-Pole ACB for Industrial Distribution | Three-phase feeders, motor-control centers, process plants, commercial buildings, and general low-voltage power distribution. | 3-pole, with the neutral connected separately when required. | Commonly 630–4,000 A; larger frames are available in some product families. | Often approximately 42–85 kA at 400–480 V, but the value must be checked at the actual operating voltage. | Adjustable overcurrent protection; coordination settings; ground-fault protection options; undervoltage release; shunt trip; auxiliary and alarm contacts. | IEC 60947-2EN 60947-2IEC 60947-1NEMA/ANSI requirements where specified by the project | Request verified Icu and Ics values, utilization category, endurance ratings, temperature-rise results, and routine-test documentation for the supplied configuration. | Check phase-terminal layout, busbar clearances, coordination study compatibility, control voltage, and whether the breaker can accept the planned cable or busduct connection. | Using a 3-pole unit where neutral isolation is required; insufficient selective coordination; incorrect voltage-specific short-circuit rating. |
| 5 | ACB with LSIG Protection | High-value feeders and incomers requiring coordinated protection against overload, short circuit, instantaneous fault, and ground fault. | 3-pole or 4-pole. | Commonly 800–6,300 A. | Typically selected within the base breaker rating, often approximately 50–100 kA depending on voltage and configuration. | Long-time, short-time, instantaneous, and ground-fault functions; adjustable delays; zone-selective interlocking; current measurement; event records on advanced trip units. | IEC 60947-2UL 1066 where applicableANSI C37.13 where specified | Obtain trip-unit accuracy data, ground-fault test results, zone-selective interlocking evidence, protection-setting ranges, and calibration or injection-test records. | Confirm CT configuration, neutral CT requirement, firmware/version control, password access, local language support, and testing equipment availability. | Incorrect protection settings can cause nuisance trips or failure to clear faults; ground-fault performance may differ between 3-pole and 4-pole versions. |
| 6 | ACB for Generator and Utility Incomer Duty | Generator output, utility incomer, bus coupler, emergency power systems, and source-transfer applications. | 3-pole or 4-pole, selected according to earthing and transfer philosophy. | Commonly 800–6,300 A. | Usually selected from approximately 42–100 kA, with generator decrement and available fault current specifically evaluated. | Adjustable short-time and instantaneous functions; reverse-power or directional protection may be handled by external relays; synchronizing and interlocking interfaces; motor operators; undervoltage releases. | IEC 60947-2IEC 60947-6-1IEC 60364NFPA 70/NEC where applicable | Request generator-duty application data, closing and tripping time, short-time withstand rating, interlocking test records, and evidence that the breaker is suitable for the specified source arrangement. | Verify control-power reliability, motor charging time, close/trip coil compatibility, phase-sequence requirements, synchronizing interface, and spare-coil availability. | Incorrect pole strategy during transfer; failure to account for generator fault-current decay; incompatible control voltage; inadequate short-time withstand during bus faults. |
| 7 | Current-Limiting or Fast-Acting ACB | Installations requiring reduced let-through energy, lower arc-flash exposure, or improved protection of downstream equipment. | 3-pole or 4-pole. | Commonly 800–4,000 A, depending on the current-limiting design. | May provide high interrupting performance, but let-through characteristics must be checked rather than inferred from the interrupting rating alone. | Fast magnetic or electronic tripping; energy-reduction modes; peak let-through current data; optional maintenance switching and remote operation. | IEC 60947-2IEC 61660 where relevant to short-circuit calculationsUL 1066 where applicable | Request verified peak let-through current, I²t data, operating-time curves, short-circuit test reports, and arc-flash energy-reduction test evidence. | Check compatibility with downstream breakers, cable withstand, busbar bracing, maintenance-mode controls, and replacement-part continuity. | Current-limiting performance may apply only at specific voltages and fault levels; poor coordination can result in unnecessary upstream tripping. |
| 8 | ACB with Power Metering and Communication | Energy management, supervisory control, building management systems, remote monitoring, and predictive-maintenance programs. | 3-pole or 4-pole; fixed or drawout. | Commonly 630–6,300 A. | Based on the underlying ACB, often approximately 42–100 kA at the specified voltage. | Voltage, current, power, energy, power factor, demand, alarms, event logs, and communication through commonly used industrial protocols. | IEC 60947-2IEC 61557-12 for power-metering performance where applicableIEC 61000 EMC requirements | Request metering accuracy class, EMC test evidence, communication-protocol documentation, cybersecurity features, firmware records, and interoperability test results. | Verify protocol registers, gateway requirements, auxiliary supply, CT accuracy, time synchronization, software licensing, and long-term firmware support. | Marketing may claim compatibility without full interoperability; metering accuracy may not cover all operating conditions; obsolete communication modules can reduce service life. |
| 9 | Marine, Offshore, or Harsh-Environment ACB | Ships, offshore platforms, coastal facilities, humid industrial sites, and locations exposed to vibration, salt mist, or elevated temperature. | 3-pole or 4-pole; fixed or drawout. | Commonly 630–4,000 A, with derating determined by enclosure, ambient temperature, and installation conditions. | Often approximately 42–85 kA, subject to the required marine or project-specific test program. | Vibration-resistant construction; corrosion protection; enhanced insulation; remote operation; undervoltage release; environmental monitoring; enclosure and terminal options. | IEC 60947-2IEC 60092 for electrical installations in shipsIEC 60529 for IP degree where applicableIACS or flag-state rules where required | Request environmental, vibration, humidity, salt-mist, EMC, and marine type-approval evidence applicable to the exact configuration and installation category. | Confirm coating system, stainless or treated hardware, storage conditions, heater requirements, derating curves, packing for sea transport, and inspection documentation. | Standard indoor ratings may not cover salt mist or vibration; corrosion can affect mechanisms and terminals; marine approval may apply only to selected variants. |
| 10 | High-Altitude or High-Ambient-Temperature ACB | Mountain installations, outdoor substations, hot industrial rooms, solar-power facilities, and regions with reduced air density or elevated ambient temperature. | 3-pole or 4-pole; fixed or drawout. | Commonly 630–4,000 A after applicable derating. | Must be verified at the actual altitude, temperature, and operating voltage; standard sea-level ratings may not apply unchanged. | Altitude compensation data; thermal derating; enhanced insulation coordination; temperature monitoring; adjustable trip settings; suitable enclosure and ventilation arrangements. | IEC 60947-2IEC 60664-1 for insulation coordinationIEC 60068 environmental tests where specified | Request altitude correction factors, temperature-rise data, insulation-clearance information, derated current and short-circuit ratings, and environmental test reports. | State site altitude, maximum and minimum ambient temperature, enclosure IP level, ventilation, solar loading, and installation orientation before quotation. | Overheating, reduced dielectric strength, nuisance tripping, and overstated interrupting performance if standard ratings are used without derating. |
