A water company orders a stand-alone motor control centre for a pump house. It is not part of any machine. Which standard is the assembly itself normally built to?

BS EN IEC 61439-2 covers power switchgear and controlgear assemblies such as switchboards, motor control centres and stand-alone control panels. BS 7671 is the tempting answer, but it covers the installation that feeds the assembly, not the assembly itself. BS EN 60204-1 is for the electrical equipment of a machine, and BS EN 60529 only defines the IP code.

BS EN 60204-1, the machine electrical standard

BS EN IEC 61439-2, the assembly standard

BS EN 60529, the enclosure protection code

BS 7671, the wiring regulations for the site

The enquiry for a new panel gives no prospective fault current for its point of connection. How does BS 7671 434.1 allow that figure to be found?

434.1 requires prospective fault current to be determined at every relevant point, by calculation, measurement or enquiry. Measurement alone is tempting, but it is only one of the three routes. The panel’s declared rating is what the fault current is compared against, not where it comes from.

Only by measuring it on site with a loop tester

Only from the rating the panel maker declares

Only by calculating it from the supply cable size

By calculation, by measurement or by enquiry

A client’s specification asks for a “fully type-tested” control panel. How should you read that against the current standard?

Type-tested and partially type-tested belong to the superseded BS EN 60439 series. The current 61439 series works by design verification from the original manufacturer and routine verification by the panel builder on every panel. Reading it as a short-circuit test on each panel is tempting, but withstand is proved once in design verification, not on every assembly.

It is the current BS EN IEC 61439 name for routine verification

It means the panel must be tested to BS 7671 Part 6 in the works

Old BS EN 60439 wording; now design and routine verification

It means each panel built gets its own short-circuit withstand test

Free mock exam

Panel building — Industrial Electrical Practice

Free topic-focused mock exam: all 30 questions on Panel building, drawn from the wider Industrial Electrical bank. 35-minute timer, 70% to pass, worked explanation on every question. Use this when you've taken the full mock once and want to drill the topics you got wrong.

Questions: 30
Time limit: 35 min
Pass mark: 70% · 21/30
Question bank: 30

Free, no sign-up. Retake as many times as you like — the questions are reshuffled, with the answer order changed.

Sample questions

01A water company orders a stand-alone motor control centre for a pump house. It is not part of any machine. Which standard is the assembly itself normally built to?
- ABS 7671, the wiring regulations for the site
- BBS EN 60204-1, the machine electrical standard
- CBS EN IEC 61439-2, the assembly standard
- DBS EN 60529, the enclosure protection code
Why: BS EN IEC 61439-2 covers power switchgear and controlgear assemblies such as switchboards, motor control centres and stand-alone control panels. BS 7671 is the tempting answer, but it covers the installation that feeds the assembly, not the assembly itself. BS EN 60204-1 is for the electrical equipment of a machine, and BS EN 60529 only defines the IP code.
02The enquiry for a new panel gives no prospective fault current for its point of connection. How does BS 7671 434.1 allow that figure to be found?
- AOnly by measuring it on site with a loop tester
- BBy calculation, by measurement or by enquiry
- COnly by calculating it from the supply cable size
- DOnly from the rating the panel maker declares
Why: 434.1 requires prospective fault current to be determined at every relevant point, by calculation, measurement or enquiry. Measurement alone is tempting, but it is only one of the three routes. The panel’s declared rating is what the fault current is compared against, not where it comes from.
03A client’s specification asks for a “fully type-tested” control panel. How should you read that against the current standard?
- AOld BS EN 60439 wording; now design and routine verification
- BIt means each panel built gets its own short-circuit withstand test
- CIt is the current BS EN IEC 61439 name for routine verification
- DIt means the panel must be tested to BS 7671 Part 6 in the works
Why: Type-tested and partially type-tested belong to the superseded BS EN 60439 series. The current 61439 series works by design verification from the original manufacturer and routine verification by the panel builder on every panel. Reading it as a short-circuit test on each panel is tempting, but withstand is proved once in design verification, not on every assembly.

Common questions

Is the Panel building mock exam free?

Yes — 100% free, no sign-up needed. Questions are pulled at random from a substantial bank, with a worked explanation on every question after you submit.

Can I retake the mock exam?

Yes. Every attempt picks a different random selection and reshuffles the options, so each retake gives you genuinely new questions. No limit on retakes.

Does this count towards the real qualification?

No — this is independent practice material. To gain the actual qualification you need to sit the official assessment through an approved provider.