Periodic test and inspections explained

Everybody knows that appliances wear our over a long period of time, but most people just assume that the wiring within their home is in a safe condition, why would they think otherwise, everything is working just like it always has done. The answer may be yes it is working, but this does not mean its safe. Over time we have invented more and more appliances and older installations were simply not designed to cope with the new demand, in your average house wired in the 1960's just one single socket and one light was fitted in each room, compare that to today when on average we fit around 3 double sockets, ceiling and possibly wall lighting in each room.

The type of wire used in older installations was insulated by rubber, paper or cotton; this insulation will have over a period of time degraded and possibly in some cases become detached from the conductor causing a serious fire/electrocution risk.

The purpose of periodic test and inspection is to check all of the wiring within your home is safe and Identify any things that could cause a possible problem in the future, the wiring in your home should be tested at a period not exceeding 10 years or at every change of hands, which ever is sooner. By testing at regular intervals you guarantee that your installation is safe and meets the current rules and regulations. Proper testing involves taking readings using test instruments and having a general look at the condition of the installed wiring and accessories, before issuing a test certificate.

Below is a list of some common problems that we have found during carrying out basic periodic inspection and testing:

Old decayed rubber cable running over a hot water pipe.

The rubber cable pictured right was found during an inspection before a house move, the client requested that we test the house prior to them moving in, the house was fully wired in old rubber cables which had badly decayed. This cable could have caused all of the pipe work within the house to become live; it also could have possibly caused a fire.

This house was fully rewired using modern PVC insulated cable before the owners moved in allowing us to complete the works with minimum disruption to the family.

Old very badly decayed cotton covered cables.

The cotton covered cables pictured right were discovered during a routine test and inspection, most of the property at some point had been rewired but just some of one lighting circuit had been left wired in the old cotton covered cables, the picture shows the cable as found at a lighting point, the insulation has nearly fully come off of the "live" (red) cable, this picture highlights the danger of old decayed cables, the missing insulation poses a risk of electric shock and fire.

The complete circuit was rewired using modern PVC cable.

Vermin damaged cables. 

The cable pictured right was found in the loft of a bungalow, rats or mice had gnawed away at the cable right down to the copper of the conductors, this cable presented a risk to anyone touching it accidentally if they went in to the loft, it also presented a fire hazard. 

The cable was replaced with a brand new one enclosed in steel conduit to help protect it from further vermin attacks.

Old Wooden Fuse Board found still being used.

The wooden fuse box pictured right was found still in use on a house that had been recommended for rewire after an inspection and test. This unit did not meet the modern standards and offered poor circuit protection with the old fuse wire system, modern split load RCD consumer units offer much safer protection and help protect against faults which can cause fires or electrocution.

The house has now been rewired and a modern slit load RCD consumer unit was put in its place.

Earthing too small and no longer meets the current regulations.

It is very common to test a house and find that earthing within the property does not meet the modern requirements and needs updating, this is due to the regulations changing as it is found that other earthing arrangements work better than existing ones. The picture on the right shows some modern bonding on a gas pipe just past the gas meter.