pretty much as the title says ....
For me it’s a txss up between the regulation about no mixing makes or mcbs or rcbos - but what if they are identical except for the name or logo
Eg lewden and control gear
AND
the design limit of 30% earth leakage on circuits with rcbo or rcds - how can this be tested / checked and what happens when people move in a new build and plug in all sorts or carp accessories
Next!
Yes. Respectively, it is impossible to create a set of standards that everyone is happy with and have no errors. On the same principal, we have courts and Judges to decide on points of law. Often, with hindsight, they can get decisions wrong.
Please let me respond to 2 of your points.
Mixed protective devices in consumer units.
A BS60898 will provide a given level of protection for a given set of electrical parameters. That said, there is no requirement for them to be of a particular size of even how they are connected into the circuit.
Universally we use din rails mainly to mount our mcbs in consumer units and distribution boards. The height or distance from the base of the din rail to the terminals on the db are different on different boards. Mixing different connecting heights on a bus bar will put mechanical strain on the bar, terminals and can eventually cause bad connections due to the expansion and contraction of the bar due to changes in temperature. Result - Fire.
A competent electrician will be able to identify where the only difference in mcb is the lable or badge. This will be noted and is fully in line with the regulations.
This regulation will hopefully stop bodgers from sticking/forcing any random breaker into consumer units.
Limiting of earth leakage to 30% downstream of a RCD (531.3.2).
I am assuming that you are referring to the above regulation. Please note that though it is a regulation, it is a consideration.
In a computer suite which has 30 2 gang switch socket outlets across 3 ring final circuits. the leakage to earth on a 10 point rfc will be around 15mA. Maybe, as much as 20mA. Without advertising manufacturers instruments, there are many instruments that can measure the leakage without breaking into the circuit. Computers, monitors and fluorescent lights can leak as much as 1mA to earth by nature.
A competent electrician/designer will take this into account when designing the circuit and will require the installer or inspector to carry out some sort of tests to confirm that the design has been followed and is correct.
As humans, we tent to look for faults before looking for the good. As my grandma used to say, "bad news travels faster than good news".
Did you know that the IET are a "not for profit charity"? If you visit a law library you will note that the cost of books of a similar size and complexity are significantly much more.
That aside, there are lots of formatting errors. There are lots of errors that have been in the regs for many years too. Personally, it is a bit unprofessional to produce a document that has so many simple formatting errors and spelling mistakes.
Finally, the CG2382 has been an easy exam to teach. I have taught 1000s of persons, many were not even electricians. I think I had 5 people who failed in total. As the questions are now random, it will be harder to pass.
I am going back to the drawing board to produce an new teaching tool for the future.
