RCD wiring standards

quickdraw2

I have recently bought a new consumer unit from a well known manufacturer and the Main Switch/fuse is configured to be connected as feed conects to the bottom and load to the top, Then to RCD Feed to top and load to bottom connectors then via busbar to mcb's feed bottom load on top, this appears to be the adopted convention for connecting RCD in consumer units, However at the same time I purchased a Non priority shower controller from the same manufacturer as a separate unit that has the RCD connected Feed in the bottom and load connected to the top. as I am fitting the shower control within the same consumer unit I have rewired the shower RCD to meet the same convention as the other RCS's within the same consumer unit. am I right ?

Does it make a difference which side the feed and load are connected ?

also what are the current conventions re connecting RCBO SP+N devices in CU's in Ireland.

Bruthal

Makes no difference, as long as the live and neutral feeds are into the one side of the RCD, and load into the other. Mix them up and it just trips when a load is on it.

Bruthal

quickdraw2 wrote: »

also what are the current conventions re connecting RCBO SP+N devices in CU's in Ireland.

RCBO`s used in domestic installations are used on items like showers as they are the MCB and RCD combined and so take up less space than seperate ones, and simpler to wire. And means any earth faults on the shower circuit will usually just affect the shower RCD.

But they can also be used on seperate socket circuits of required, which would restrict any earth fault problems to the affected circuit, and may make finding such faults a bit easier. Usually with domestic CU`s here, one RCD covering all socket MCB`s is used though.

quickdraw2

While I can appreciate that the RCD may be connected either way but not phase to neutral reversed, I can see that the test button , neutral to earth may operate slightly differently if incorrectly connected, and have noticed comments about RCD failures in units (from other manufacturers) not connected in accordance with the conventions, I find it somewhat unsettelling that a major manufacturer would supply panels connected in different ways that may be integrated within the same installation.

quickdraw2

Scarey ! If you are expecting the convention.

Bruthal

quickdraw2 wrote: »

While I can appreciate that the RCD may be connected either way but not phase to neutral reversed

If the Live and Neutral are reversed it would still work properly as well. But we would connect the live and neutral according to the labels.

I can see that the test button , neutral to earth may operate slightly differently if incorrectly connected, and have noticed comments about RCD failures in units (from other manufacturers) not connected in accordance with the conventions, I find it somewhat unsettelling that a major manufacturer would supply panels connected in different ways that may be integrated within the same installation.

The test button does not connect to earth, it just bypasses one of the current measuring coils in the RCD as it connects a resistor from the live to neutral in it, this trips it to show its working both electrically and mechanically. An earth fault will cause the earth fault amount of current to be missing from the neutral coil in the same way the test button does. But the real function of the RCD is to trip in the event of a person getting an electrical shock.

A competent electrician would be fully aware of the different ways an RCD can be connected, and it would not be of any concern to see them connected in opposite directions.

quickdraw2

your right robbie,
Im just rattellimg off to quick, and had not considered my response,
anyway my comment that if there is a convention regarding connection, straying from it may cause problems because most people would expect the convention to be followed.

M cebee

i think this is odd too-the rcd's wired in the top on some boards

also the breakers and terminals on boards are ip2x-you can't stick your finger into them

-yet they're supplied with un-insulated copper busbar

M cebee

the GE euroline is supplied with un-insulated busbar anyhow

i know they're not all like that

Bruthal

M cebee wrote: »

i think this is odd too-the rcd's wired in the top on some boards

Do you see any problems with it though?