| 1 Confirm the correct breaker category | Identify whether the product is an MCB, MCCB, RCCB, RCBO, or another protective device. Match the device to the application, installation type, and required protection function. | IEC 60898-1 for circuit-breakers used in household and similar installations. IEC 60947-2 for low-voltage circuit-breakers used in industrial applications. | The product designation, intended use, rated voltage, and operating environment must match the project specification and local electrical code. | Product datasheet, technical construction file, product classification, and the applicable standard edition stated by the manufacturer. | Do not compare prices until the product type and protection function have been technically confirmed. |
| 2 Check voltage, current, and frequency ratings | Verify rated operational voltage (Ue), rated current (In), number of poles, AC or DC suitability, and system frequency such as 50 Hz or 60 Hz. | The ratings must be compatible with the destination country's nominal supply system and the installation's distribution design. | The voltage rating is not lower than the system voltage, the current rating is suitable for the calculated load, and the pole arrangement matches the circuit. | Nameplate photographs, rating tables, wiring diagrams, and a declaration identifying AC/DC limitations. | Compare the nameplate with the single-line diagram and local supply parameters before placing an order. |
| 3 Verify short-circuit interruption capability | Check rated short-circuit capacity, including Icn for applicable MCBs and Icu/Ics where applicable for industrial circuit-breakers. Confirm the intended installation point. | Short-circuit performance is evaluated under the applicable product standard, commonly IEC 60898-1 or IEC 60947-2. | The declared interruption rating must meet or exceed the prospective short-circuit current at the installation location, with the required service performance specified by the project. | Type-test report, short-circuit test information, Icu/Ics or Icn data, and coordination or backup-protection information where relevant. | Have a qualified engineer confirm the prospective fault current; never select a breaker only by its ampere rating. |
| 4 Select the correct tripping characteristics | Review instantaneous trip characteristic, thermal or electronic settings, overload curve, and tolerance. Common MCB curves include B, C, and D, but availability and permitted use vary by market. | Trip behavior must comply with the applicable product standard and the destination market's installation rules. | The tripping profile protects the conductor and equipment while avoiding nuisance trips during normal inrush or motor starting conditions. | Time-current curves, setting ranges, calibration information, and coordination/selectivity data. | Match the curve or setting to cable ampacity, load type, inrush current, and upstream/downstream protective devices. |
| 5 Confirm residual-current protection requirements | For RCCBs or RCBOs, verify residual operating current, such as 30 mA or 100 mA, type of residual-current detection, rated current, number of poles, and test-button function. | IEC 61008-1 applies to RCCBs without overcurrent protection. IEC 61009-1 applies to RCBOs with overcurrent protection. | The residual-current rating and detection type are appropriate for the shock-protection, fire-protection, and load requirements defined by local regulations. | Residual-current test report, sensitivity and trip-time data, wiring instructions, and compatibility information for electronic loads or inverters. | Obtain local code guidance from a licensed electrical professional, especially for wet areas, outdoor circuits, and special installations. |
| 6 Check market access and conformity evidence | Identify the destination market's mandatory approval, marking, registration, import, labeling, and language requirements. A voluntary certification is not automatically a legal authorization. | Requirements may include the jurisdiction's adopted IEC or national standard, conformity-assessment rules, and recognized certification schemes. Confirm the current local edition before purchase. | The marking, rating label, instructions, and conformity documents are consistent with the exact model, configuration, and destination country. | Declaration of conformity, certificate scope, accredited laboratory report, label artwork, instruction manual, and traceability information. | Ask the local authority, importer, inspection body, or certification specialist to validate market eligibility before shipment. |
| 7 Assess quality, traceability, and lifecycle support | Review terminal temperature performance, mechanical endurance, electrical endurance, ingress protection where relevant, operating temperature, spare-part policy, and warranty terms. | The applicable product standard defines relevant performance tests; installation conditions may also be governed by the destination country's wiring regulations. | Production batches are traceable, test records are available, terminals accept the specified conductor sizes, and replacement or technical support is available for the expected service life. | Factory inspection records, routine test records, batch or serial traceability, installation manual, warranty terms, and change-control policy. | Approve a pre-production sample, perform incoming inspection, and define acceptance tests in the purchase contract. |