Electrical Safety Checks
Electrical Testing - Why is it so important?
If your home or business has an electrical supply (which I am guessing most do) then I am sure you have socket outlets, light fittings, switches etc present in the installation.
This post will cover why we carry out testing and what is involved in the testing process.
In the UK we carry out several types of test:
Electrical installation Condition Report - This is an inspection and test carried out on an existing installation which is currently in service
Electrical Installation Certificate - This is an inspection and test carried out before any circuit is energised, for example on new installs/alterations or additions to an existing installation
Minor Electrical Installation Works Certificate - This is a limited inspection and test carried out when a minor install is carried out ie replacing a socket outlet or light fitting for example
In the UK there are also several other types of inspection we carry out for example fire alarm testing or emergency lighting testing but these topics will not be covered here.
Electrical Installation Condition Report
What is it?
An electrical installation condition report or EICR is a survey of an existing installation and is a relatively new thing which has only been used since the 1st January 2012, previously to this we carried out a Periodic Inspection Report.
Now there is a major difference between the two, the old PIR was four pages long and the new EICR is nine pages long and there is a reason for this:
We have three fault codes in the current EICR:
Code One: Dangerous Situation
Code Two: Potentially Dangerous
Code Three: Observations and Recommendations
The old PIR had a further fault code:
Code Four: Does not comply with current regulations
Ok so basically a lot of contractors would use code four to get around most faults and save themselves some work and sign off the installation.
Our governing bodies ie NICEIC, ECA, IEE etc got together and decided to stop this 'get around' practice and created this new beast the EICR.
The EICR is a LOT more thorough and really makes you examine the installation in depth with three pages of tick lists which the old PIR did not cover.
There are two final outcomes from the EICR - Satisfactory or Unsatisfactory simple as that!
If you receive any Code One or Code Two faults an unsatisfactory report is issued listing any dangerous situations.
If you receive any Code Three faults a satisfactory report is issued listing any recommendations.
Why do we carry out testing and inspections?
Pretty good question?
Ok lets break it down, I often say to people electrical testing is like going to the doctors surgery, most men will not get up one day and say 'I am going for a check up today' this just does not happen!
Now if there is a sniffle or he catches a bit of man flu its straight to the doctors surgery because he is at the deaths door (probably has a sore throat!)
Anyway you catch my drift most peoples installations will be fine and never give them any problems until bang and fuses start blowing or things are not working ie light fittings.
That is usually when I come in to the fray 'can you help me? Everytime I plug such and such in the fuse blows'.
Ok so I visit the property and usually in most cases find several pretty major faults, I fix whatever the problem is and usually recommend that an electrical installation condition report is carried out.
An average test on a three bedroom semi detached house can take anything up to six hours depending on the number of points within the installation. By points I am referring to the number of sockets, switches, light fittings etc.
Also the number of circuits ie Lights, Sockets, Water Heater, Shower etc
Within the report every single aspect of the installation is listed in the 'Schedule of circuit details and test results' for example the upstairs lighting is wired in 1.5mm twin and earth and has 7 lights on the circuit.
So if we had a 6 way consumer unit there would be six circuits listed ie 1. Lights, 2. Shower and so on.
We then test each and every circuit using a combination of 'dead' and 'live' testing.
The dead tests are carried out with the power shut down and there are specific tests we carry out:
Continuity of bonding conductors (R1 and R2)
Continuity of ring final conductors (end to end)
The live test are carried out with the power in and the specific test we carry out:
External earth fault loop impedance (Ze)
Earth fault loop impedance (Zs)
Residual Current Device testing
Functional testing of assemblies
There are also some addtional tests we carry out in specific types of installations ie three phase supplies, earth rods amongst others but the above is the usual bog standard set of test procedures for your average domestic home.
By the way I will quickly tell you there are three main types of incoming supply in the UK:
TT - No main earth is provided by the distributor so an earth rod must be installed
TN-S - An earth is obtained from the metal sheath of the incoming supply
TN-C-S - An earth is supplied via a PEN conductor
The most common type is the TN-C-S although the other two can still be found quite regularly.
What are we specifically looking for?
During the inspection and test of an installation I can usually tell within five minutes what amount of investigation is required.
Due to my experience in this field I am taking constant snapshots in my head, cracked socket there, faulty light fitting here, no isolator for that equipment.
There is a wide range of processes that go into the inspection side of a EICR.