Quality control: from component receiving to cabinet shipment, all four gates are documented
Quality control isn't the last step — it's four gates
"We take quality seriously" means nothing. Our position is this: from component receiving to cabinet shipment, four gates each own one stage, and every step leaves a record you can check.
| Gate | Stage | What we do |
|---|---|---|
| IQC | Incoming inspection | Components checked item by item against the inspection sheet + BOM on arrival; brand/model/batch verified for critical parts |
| IPQC | In-process inspection | Sheet metal dimensions, coating film thickness, terminal torque, and assembly condition sampled by operation |
| FQC | Final inspection | Final check of cabinet appearance, dimensions, internal components, and wiring-to-drawing consistency |
| OQC | Factory tests | 100% powered testing + dielectric withstand + grounding + insulation, records delivered with the package |
Factory testing: every unit goes through it, no sampling
Powered testing, dielectric withstand, grounding, insulation — these four are mandatory on every cabinet we ship, not "a few units to show willing."
| Test item | Parameter / standard |
|---|---|
| Powered functional test | Every unit powered; each circuit verified against the secondary schematic |
| Power-frequency dielectric withstand test | 2500V / 1min |
| Grounding continuity | Grounding resistance ≤4Ω |
| Insulation resistance | Performed and documented to GB/T 7251 |
| Temperature-rise verification (assembled unit) | Busbar temperature rise after assembly ≤70K (per GB/T 14048.1) |
| Records archived | Test records delivered with the as-built documentation package |
Dielectric and insulation testing per GB/T 7251 (equivalent to IEC 61439); temperature-rise verification per GB/T 14048.1. Test records are not kept at the factory — they ship with the as-built documentation package.
How quality records reach you
- As-built documentation package — Single-line diagram + control schematics + terminal diagram + factory test records, one set shipped with the goods, so you have documentation for on-site commissioning and future maintenance;
- Component list (BOM) — Brand, model and quantity of every component inside the cabinet, itemized;
- Certificates and reports — Product certificates and test reports included; scope is limited to the original documents;
- Factory inspection — Pre-shipment factory inspection is welcome, or we can provide photos and video of the goods for confirmation.
FAQ: Common quality control questions
Common quality control questions
Is factory testing done on every unit?
Yes. We run 100% powered testing, not batch sampling. Every unit is checked circuit by circuit against the control schematics, and undergoes power-frequency withstand voltage, grounding continuity and insulation resistance tests. Test records ship with the as-built documentation package.
What are the specific parameters for the withstand voltage and grounding tests?
Power-frequency withstand voltage 2500V / 1min; grounding continuity ground resistance ≤4Ω; insulation resistance performed and documented to GB/T 7251. All of these are itemized and traceable in the factory test sheet.
How is incoming material controlled?
Components are checked item by item against the inspection sheet and BOM on arrival (IQC incoming inspection), with IPQC in-process patrol inspection and FQC final inspection before shipment; for critical parts (such as breakers and contactors), brand, model and batch are verified.
What happens if a problem occurs during the warranty period?
Warranty is 1 year. We start with remote diagnosis (photos/video/description); anything that can be resolved remotely does not require a site visit. If repair or part replacement is needed, it is handled per the contract, and our spare parts stock keeps common components on hand. SeeWarranty & after-sales.
Want to see a redacted sample test record first?
Write to us to request a factory test record sample (redacted) for a specific model, or schedule a factory inspection and watch all four tests run on site.
Request a test record samplesales@gu-electric.com · WhatsApp: +86 186 5712 0011 · ISO 9001:2015 · CE (LVD+EMC) · IP65 test report