All of the items shown below have been discovered by the CTS engineer during the course of routine inspection and testing in the Scarborough area. 

The items were either in use or were ready to be used when they were found!

Please note that all the images and text used on this website are copyright © and are the property of Columbus Services of Scarborough, North Yorkshire, YO12 7JT. They must not be reproduced or stored in any form without permission.

At the end of an interesting the week we have come across another table lamp fitted with a brass lamp holder that has in the past had a plug fitted without the cable clamp being correctly used, this has resulted in the earth wire pulling free from the earth pin at some point! 

It is impossible to even guess how long it has been in daily use in that very dangerous condition...

The plug has now been correctly fitted and the lamp has passed the the inspection and testing procedure!

I was doing a job this week and had a nice looking brass table lamp to test. As the plug needed changing I did a quick test to check it was actually worth fitting a plug but could not get any earth continuity.  The reason for this became very obvious when I looked inside the plug!

If the cable clamp had been in place and doing its job then the earth wire would have most probably remained connected to the terminal. Oh and dont forget that a 13 amp fuse is not the value that a table lamp requires...

Once a new mains plug was fitted and a 3 amp fuse inserted the lamp then passed without any further problem!

We came across this badly wired plug during some routine testing a few days ago! 

Obviously whoever fitted it could not be bothered with feeding the conductors under the cable clamp or changing the brown 13 amp fuse for a red 3 amp one as it was on a table lamp...

I do not think that we see as many badly fitted plugs as we once did, however we do still see enough dodgy examples to make you just a little bit worried!

The hand held electric pistol drill would not work and on opening up the plug it was very obvious why the drill would not work! Having refitted the plug ensuring that the cord grip was secure, the drill was good to go again as it passed the PAT inspection.

While testing an office recently, I moved a set of A4 filing trays that were on a desk & discovered this damaged wall socket. It was actually in use with two plugs connected and it was not that easy to safely disconnect the power lead going to the computer system that I was wanting to test! 

However I am sure that by now the office manager will have contacted an electrician to come and replace the damaged 13 amp socket and broken wall box!

Here is a plug that was fitted to a small oil filled radiator in a local business that was being tested. As you can see the grub screw on the earth terminal has totally fallen out and the grub screw on the negative terminal was very loose and just about to do the same - this loose connection has resulted in some overheating of the cable as the blue rubber insulation has clearly changed colour as a result! 

Any item of equipment that gets moved regularly such as heaters and extension leads can suffer from this problem and so requires regular inspection...

During the course of some inspection and testing this week I came across this rather "interestingly" wired 13 amp plug that was fitted to a table lamp.

It was just too good not to share and so here is the first new exhibit for 2018 in the CTS Black Museum.

Well worth checking regularly!

If you have a computer tower then it really is worth regularly checking that the air vents are not getting clogged with dust and fluff. The tower shown below was sitting on the floor next to a desk and as you can see from the before and after photographs there had been a considerable build up of dust on the air intake. This would really not have helped keep the components nice and cool inside the case. 

If computers run too hot they may run slowly or even shut down to protect themselves. Prolonged operation at elevated temperatures can shorten the life of any electronic device and lead to possible premature failure! 


I came across this rather interesting example of very dodgy electrical practice recently!

Now there is absolutely nothing wrong with having an inline cord switch on your bedside light is there?

However when you decide fit a mains press switch that is designed to be mounted inside a case and then just wrap a little bit of plastic insulating tape around it to cover up the live terminals - personally I think that you are living rather close to the edge!

The edge of oblivion that is...

Once upon a time having wiring like this was quite acceptable - however it is certainly not acceptable in this day and age! 
The two bayonet light fittings on the 1950's dressing table that this plug was originally connected will need re-wiring before they are in use again...

These days you cannot use Figure 8 power cables as flex must have two layers of insulation, one being the coloured conductor insulation and the other insulation layer being the outside sheath of the flex...

If you have a very nice looking decorative brass table lamp fitted with a length of three core mains flex what makes you suddenly decide that there is no need to connect the earth cable? 

It certainly beats me...

Anyway a new BS 13 amp plug with sheathed pins has been fitted along with a 3 amp fuse and it then passed its PAT with flying colours!

A lack of care when storing the mains cable against the thin sheet metal radiator on the back of a fridge resulted in the cut you can see here that has damaged two layers of insulation and has exposed the live copper conductor!

Avoiding damage like this will save you money...

The 13 amp plug shown here on the left was fitted to a brass table lamp. 

As you can see not only had it lost the important grub screw that secures the earth wire it is also had a 13 amp fuse installed - neither of these things are very good from the point of electrical safety!

A new BS1363 mains plug with sheathed pins was fitted at this was one of the the old style plugs with the unsheathed plain brass live and neutral pins and as it was due to be sold it had to be replaced.

Here is a typical example of the type of damage that is often found on the flex on a vacuum cleaner fitted with a powered beater bar.

The friction of the rotating brushes causes a build up of heat that softens the plastic insulation very fast & it then gets scuffed. It is not unusual to find that the copper conductors have become exposed, although not in this particular case...

It is always very useful to know what value of fuse is fitted in a particular mains plug - but not when you can find out by looking through a large hole in the back of the plug casing...

This particular example was removed from a table lamp and replaced with a new 13A BS1363 mains plug fitted with a 3 amp fuse.

When the outer sheath of a flex has pulled back as it has in this example exposing the coloured cores it is time to get the switch either re-wired or replaced by a suitably qualified person.

When your favourite table lamp has a flex containing cores coloured red, black and green like the example shown here then it is time to get it inspected by a suitably qualified person and most likely rewired, as this wiring colour code was replaced by the current brown, blue and green / yellow scheme in the early 1970's...

It has been a while since I have come across a new exhibit for "the black museum" but a really good one  cropped up today!
The 13 amp plug shown on the left was fitted to the mains lead of an arc welder. Why whoever fitted it decided that it was not necessary to connect up the earth wire I really do not know - but there you go!

Needless to say a new sheathed pin 13A plug has been fitted and the earth conductor is now in use!

Here there is another example that shows a similar problem to the one described below, however this plug has sustained much more heat damage. 

The plug was removed from a tumble dryer during PAT because of the area of melted plastic that can be clearly seen at the bottom of the fuse slot. 

Obviously a poor contact between the fuse holder and the fuse cap has generated quite a lot of heat that has then lead to the quite extensive damage. It goes to show that moulded plugs on high wattage equipment can have issues and do need checking!

The 13A plug shown below was recently removed from a washing machine, overheating and charring can be clearly seen at one end of the fuse slot. The fuse holder clips had got bent and so had not been gripping the fuse cap tightly enough. This might have been caused by the fuse carrier being inserted at an angle and not in line with the fuse holder at some point in the past. The lack of firm contact between the clips and the metal fuse cap has resulted in overheating that has blackened both the clip and the fuse cap. If this fault had not been discovered then potentially failure or even a fire could have started in the plug or the wall socket!

When the flex on your favourite table lamp looks like this, I am afraid that it is time to just accept the fact that it really does need replacing!


Why does the 13 amp mains plug below have a hair bobble wrapped around it when it was fitted to a heater?


The plug has been dropped and the screw holding the back of the plug in place had broken through the plastic so the back kept on falling off and exposing all of the terminals and the fuse inside.


Fit a new plug or fit a hair bobble to hold it together? 

Obviously the best and only safe option is: TO FIT A NEW PLUG!

Shown below is some damage on the flex of a vacuum cleaner. This is quite a common problem caused when the flex gets caught by the beater bar and the plastic insulation gets worn off quickly when it softens due to the heat from the friction of the revolving brushes. Potentially a dangerous electric shock situation especially when the live conductor becomes exposed! Using insulating tape is not a satisfactory long term repair method.

What is an appliance test label actually worth? 

If the person doing the testing either has a poor grasp of what the job entails or if they are only interested in charging the customer the cash for a "test" then the pass label can become totally meaningless! 

The plug shown in the picture below was on a table lamp that had a switched brass bayonet lamp holder fitted.

1) Figure 8 flex with just a single insulation layer is not permitted these days, flex has to be double sheathed.

2) Twin flex supplying a brass bayonet lamp holder is not good practice as an earth lead is usually required.

3) A table lamp needs a 3 amp fuse, it certainly does not require a 13 amp fuse like the one in this plug.

Whoever stuck a test label onto that appliance posed a danger to themselves and to others! 

They were actually obtaining money under false pretences, charging customers money for a job that was not being done correctly. The consequences of their actions in a worst case scenario could be a shock or a fire...

Always choose a reputable test engineer to ensure that your appliance testing is carried out safely & correctly.


If the flex on an appliance is too short then there are much better ways of extending it than the method shown here on the right!

Getting an approved 13A extension lead is possibly the easiest option to take or in some circumstances the fitting an approved mains flex connector might be the answer...


The cloth covered flexible cable looked rather old and out of place on this 13A extension lead. 

On opening up the plug the age of the flex became very obvious from the rubber insulation coloured red, black and green. It was in the early 1970's that the colours of flexible cable cores in the UK changed to the current brown. blue and green/yellow so this is certainly vintage flex that is definitely not suitable for use on the 230v mains supply again, but as another exhibit for the CTS black museum it is excellent...

A "Triple Fault" Exhibit...

Shown here is the mains plug that was recently found fitted to a large brass table lamp...

As you can see the 13A fuse and disconnected earth wire are both areas of concern.

Slightly less obvious from the picture is the fact that the cable clamping strap was not tightened down. 

This is possibly the reason why the earth wire had been pulled off its terminal.

Often seen in NASA photographs covering satellites and parts of the International Space Station gold foil is however rather out of place wrapped around the fuse of in a 13A plug! 

I have seen quite a number of fuses wrapped in silver foil but never before in gold foil.

Only goes to show that there is a first time for everything!

The pictures below show a quite a "shocking" example of bad wiring on a table lamp cord switch and using it could really spoil your day! When this item was found it was in use and switched on! Not only is the sheath of the flex not gripped by the cord clamp but the live and neutral wires are reversed as well...

Have a look at the two close-up pictures that are under the larger picture below to see the problem.

The following pictures give you a chance to play "spot the problem".

You will not find it very difficult!

The photograph of the plug below is one of my favourites - a "classic" exhibit.

All of these taped joints shown below were from the same premises!

Have you spotted that the 13A plug shown below has no fuse?

Just because it is possible to fit three flexes into the plug below does not mean its a good idea does it?

The two photos below show a rather alternative method of connecting cable to the pins of a 13 amp plug!

It was possible to pull the back off the plug!

It certainly makes you think... 

Remember that you can contact CTS on 01723 362746.

CTS providing a service and not just a price since 2005...


  All images & text used on this website are copyright © & the property of Columbus Services.