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Replacement Consumer Units

Replacement Consumer Units

Probably the best thing you can do in order to improve the safety of a domestic electrical installation is to install an up to date consumer unit (fuse board).  As technology develops, the safety devices housed within a modern consumer unit offer far more protection than in earlier years.  The main development in the regulations is the introduction of RCD protection or Residual Current Devices.  These are ‘life saving’ devices which are designed to trip out within a very short time period if and when a fault develops.  Bearing in mind that this ‘fault’ could be someone receiving an electric shock, they can literally save your life.  If your current consumer unit or, fuse board, does not contain any RCD protection then you should have it replaced as soon as possible.  If your old style fuse board looks like any of the following, then you are well overdue for an upgrade;

The RCD constantly compares the current that travels through its LINE conductors ie. the LIVE and the NEUTRAL.  In a healthy electrical system, all the current that flows into a socket for example and through an appliance, through the LIVE conductor, then continues to travel back through and out of the system via the NEUTRAL conductor.  Thus the currents in both LIVE and NEUTRAL terminals on a RCD should be exactly the same. 

If a fault occurs, then current will flow through the ‘circuit protective conductor’ or CPC (More commonly known as the Earth).  This can also occur as LEAKAGE through things like static or other effects.  If this happens, then not all the current that was carried by the LIVE conductor will now return through the NEUTRAL because some has taken the EARTH FAULT PATH.  In this case the RCD will switch off the power, very quickly as it knows there is a fault.  Some examples of RCD devices are shown below;

As you can see, an RCD can take different forms depending on its application.  They all incorporate the same technology in order to compare current flow in the two LINE conductors and if they are not exactly the same it will trip.  This can, however, uncover more faults in the installation than ever before.  For example, you may renew your consumer unit and introduce RCDs, and even though you thought everything was fine before, you now have many problems.  This can be seen as a draw back of having a consumer unit replaced but at the end of the day having faults that you just don’t know about should not really be an option.  Ignorance is not bliss.

Click Here, if you are currently experiencing RCD tripping problems.

The other main change in the regulations to date is the introduction of completely metal Consumer units.  It is now the case that ALL switch gear (Including consumer units) should be contained within fireproof cases.  This essentially means they need to be metal.  Whilst this is not a reason in itself to have a replacement consumer unit installed, next time you do it should be metal.

Click Here, for more info on SPDs and AFDDs (18th edition regulations)