When IEC 61439-1 replaced IEC 60439-1 in 2009, 'type-tested assembly' (TTA) became the global benchmark for LV switchgear quality. Modern Saudi projects demand it by name. Here's what it actually verifies, and the gap consultants still miss.
Four ideas to carry into the next specification conversation you have.
13 tests at an accredited lab on a prototype: temperature rise, short-circuit, dielectric, arc, IP rating, mechanical operation. Pass once = the design is approved.
Insulation resistance, wiring continuity, dielectric test, functional check. Every panel that leaves the factory must pass these, even if the design was type-tested last decade.
TTA without routine = a paper certificate, no built quality. Routine without TTA = manufacturer claims, no third-party design proof. Spec both.
ASTA, KEMA, CESI, independent accredited labs. A type-test certificate from the manufacturer's own lab is increasingly rejected.
What an accredited type-test lab actually runs on the prototype.
| # | Verification | Reference clause |
|---|---|---|
| 1 | Strength of materials and parts | 10.2 |
| 2 | Degree of protection (IP) | 10.3 |
| 3 | Clearances and creepage | 10.4 |
| 4 | Protection against electric shock | 10.5 |
| 5 | Incorporation of switching devices | 10.6 |
| 6 | Internal electrical circuits | 10.7 |
| 7 | Terminals for external conductors | 10.8 |
| 8 | Dielectric properties | 10.9 |
| 9 | Temperature-rise limits | 10.10 |
| 10 | Short-circuit withstand strength | 10.11 |
| 11 | Electromagnetic compatibility (EMC) | 10.12 |
| 12 | Mechanical operation | 10.13 |
| 13 | Internal arc tests (option) | Annex AA |
Five lines that separate a real TTA from a paper one.
ASTA (UK), KEMA (NL), CESI (IT), SGS, TÜV. The lab must be ISO 17025 accredited to issue legally valid certificates. Manufacturer-owned labs are common, but rarely accepted on Saudi government and oil-and-gas tenders.
The headline number on every TTA. 50 kA / 1 s is mid-range; 80 kA / 1 s is premium. The certificate must list the exact Icw the prototype survived, and your assembly's rating cannot exceed it.
The prototype runs at rated current until temperatures stabilise. Busbar joints, terminals, enclosure surface, all measured. If your project's enclosure is bigger or busbars are thinner than the tested one, the cert doesn't transfer.
AFLR + 50 kA / 1 s means the panel survived an internal arc of 50 kA for 1 second without ejecting hot gases out the front, side, rear, or to access points. Saudi government and hospital tenders now demand 80 kA AFLR.
TTA is one prototype. The factory must run routine tests on every assembled panel: dielectric, insulation resistance, continuity, functional. Demand the routine test report with the panel itself, not separately on request.
Our Schneider-licensed assembly line ships every panel with full IEC 61439-1 routine test reports. Type-test certificates from ASTA and KEMA, AFLR 80 kA available.
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