| Product Scope | Whether the manufacturer has the required current-product category rather than acting only as a trading company. | Current transformers Shunt resistors Busbars Hall-effect sensors Rogowski coils | Documented production capability for the exact product type, voltage class, current range, and installation environment required by the project. | Incorrect product selection, unstable quality, and limited technical accountability. | Essential |
| Electrical Accuracy | Measurement accuracy under the specified current, frequency, temperature, burden, and load conditions. | Accuracy class, ratio error, phase displacement, linearity, temperature coefficient, and calibration records. | For metering current transformers, the requested accuracy class should be confirmed against the applicable IEC or equivalent national standard. Typical classes include 0.1, 0.2, 0.5, and 1.0. | Incorrect energy readings, protection maloperation, or non-compliance with the end user's design. | Critical |
| Rated Current Range | Compatibility with continuous current, overload current, short-time current, and the required measurement range. | Rated primary current, rated secondary current, overload capability, short-time thermal current, and dynamic current rating. | The supplier should provide test data for the complete operating range, not only the nominal current point. | Thermal damage, saturation, signal distortion, or premature component failure. | Critical |
| Insulation and Safety | Electrical isolation and insulation performance for the intended voltage and installation category. | Insulation resistance, power-frequency withstand voltage, impulse withstand voltage, creepage distance, clearance, and dielectric test reports. | Values must match the applicable product standard and the buyer's system voltage. For medium- and high-voltage applications, type-test evidence is normally required. | Electric shock, flashover, insulation breakdown, and serious equipment damage. | Critical |
| Applicable Standards | Whether the product is designed and tested to standards recognized in the destination market. | IEC 61869 series IEC 60044 legacy references UL requirements where applicable RoHS REACH | The manufacturer should identify the exact standard edition, product scope, test laboratory, and certificate holder. A generic “CE” claim alone is not sufficient technical evidence. | Import delays, failed customer audits, redesign costs, or rejection by an inspection body. | Critical |
| Quality Management | Effectiveness of the factory's quality-control system and traceability process. | ISO 9001 certificate, incoming inspection, in-process inspection, final testing, nonconformity records, corrective-action reports, and batch traceability. | A valid certificate should match the legal manufacturing entity and production address. Certificates should be checked with the issuing organization where practical. | Uncontrolled process variation and difficulty identifying the cause of field failures. | High |
| Factory Capability | Actual manufacturing resources, process control, and capacity for repeat orders. | Production-line photographs or audit results, winding and assembly equipment, calibration system, test benches, staffing, and monthly capacity evidence. | Capacity should be demonstrated using the buyer's forecast, required lead time, product complexity, and peak-season demand rather than a general sales statement. | Late delivery, subcontracting without approval, and inconsistent product quality. | High |
| Testing and Calibration | Whether finished products are tested individually or only sampled. | Ratio and polarity tests, insulation tests, resistance tests, accuracy tests, temperature testing, calibration equipment, and test-record retention. | 100% routine testing is preferred for safety-critical electrical characteristics; sampling plans should be documented for other inspections. | Defective units may reach the customer without detection. | Critical |
| Materials and Construction | Consistency and suitability of magnetic cores, copper or aluminum conductors, insulation materials, terminals, housings, and encapsulation compounds. | Material specifications, approved-vendor list, incoming material certificates, design drawings, and change-control procedure. | Materials should be traceable to defined specifications, with formal approval required for substitutions or design changes. | Loss of accuracy, overheating, corrosion, cracking, or reduced service life. | High |
| Environmental Performance | Resistance to temperature, humidity, vibration, dust, salt mist, and other installation conditions. | Operating temperature range, storage temperature, IP rating, humidity testing, vibration testing, corrosion testing, and altitude limitations. | Environmental ratings should be selected from the actual application conditions. IP ratings must be supported by the relevant test method and enclosure design. | Drift, corrosion, moisture ingress, mechanical failure, or unreliable readings in the field. | High |
| Customization Capability | Ability to adapt dimensions, terminals, mounting, insulation, output signals, labels, packaging, and documentation. | Approved drawings, engineering-change process, prototype procedure, sample approval, tooling ownership, and design-for-manufacturing review. | Custom requirements should be confirmed in a signed technical specification before quotation or mass production. | Fitment problems, repeated sample revisions, and unexpected tooling or engineering charges. | High |
| Sample and Pilot Validation | Whether the supplier can support a controlled sample-to-production transition. | Pre-production samples, first-article inspection, reliability testing, pilot-batch report, and comparison between approved samples and mass-production units. | Approval should cover electrical, mechanical, dimensional, marking, packaging, and documentation requirements. | Mass-produced units may differ from the approved sample. | High |
| Export and Documentation | Readiness to support international shipments and technical documentation requirements. | Commercial invoice, packing list, certificate of origin, HS-code support, inspection documents, installation instructions, drawings, and English test reports. | Documents should be consistent with the legal exporter, product description, quantity, and destination-country requirements. | Customs delays, installation errors, and additional import or inspection costs. | High |
| Lead Time and Supply Continuity | Ability to deliver samples and repeat orders reliably, including during component shortages or seasonal peaks. | Quoted sample lead time, production lead time, capacity plan, safety-stock policy, approved backup materials, and on-time-delivery records. | Lead time should be stated separately for samples, tooling, pilot batches, and repeat production, with assumptions clearly defined. | Project delays, production stoppages, and emergency freight expenses. | High |
| Warranty and After-Sales Support | Clarity of warranty coverage and response process for technical or quality issues. | Warranty period, exclusions, failure-analysis procedure, replacement policy, response time, remote support, and corrective-action process. | Commercial terms should define responsibility for verified manufacturing defects, transport damage, installation errors, and unauthorized modifications. | Long dispute cycles and limited recovery when field failures occur. | High |
| Total Cost of Ownership | Overall purchasing cost rather than unit price alone. | Unit price, tooling, testing, packaging, freight, duties, inspection, spare parts, failure rate, and expected service life. | The lowest quotation should not be selected without comparing specifications, test coverage, warranty terms, delivery reliability, and lifecycle risk. | Hidden costs, premature replacement, and higher project risk. | High |