There are precautions which can be taken to prevent danger from portable electrical equipment in premises where risks are generally low, like offices or libraries.

Portable equipment is equipment that has a cable and plug, and can be easily moved around e.g. kettles, heaters, fans, lights, televisions, as well as office equipment like computers, faxes and photocopiers. The risks from portable electrical equipment used in offices is low, but if you have never had an inspection system or if maintenance has been neglected, there is a greater chance that some equipment may have become dangerous. Leads and plugs, or sometimes the equipment itself, can become damaged and this may result in an electric shock. Damaged equipment can also cause fires.

There is a lot of electrical equipment in offices and the best way to maintain it is to visually inspect it. By looking for the visible signs of damage or faults, and putting them right, you will prevent most electrical accidents from occurring. Things to look out for on the equipment, cable and plug (after disconnecting it) are signs of:

•
 damage, e.g. cuts or abrasions to the cable covering;
•
 damage to the plug e.g. the casing is cracked or the pins are bent;
•
 non-standard joints, including taped joints, in the cable;

•

 the outer covering of the cable not being gripped where it enters the plug or equipment. Look to see if the coloured insulation of the internal wires is showing - it shouldn't be;
•
 equipment that has been used in conditions where it is not suitable, such as a wet or dusty workplace;
•
 damage to the outer cover of the equipment or obvious loose parts;
•
 overheating (burn marks)

A formal inspection could also include removal of the disconnected plug cover to check:

•
 the cord grip is holding the outer sheath of the cable tightly;
•
 the wires, including the earth where fitted, are attached to the correct terminals;
•
 no bare wire is visible other than at the terminals;
•
 the terminal screws are tight;
•
 there is no sign of internal damage, overheating or entry of liquid, dust or dirt.

It is not necessary to have an electrician carry out this visual inspection. Any competent member of staff can do it, with enough knowledge and training. Users should be encouraged to look critically at the equipment they use, and to look for damage to the outside of the equipment and its lead and plug before they use it, but they should not take the plug apart.

However, some faults cannot be detected by looking, particularly lack of continuous earths. For some equipment the earth is essential to safety. Therefore, all earthed equipment and most leads and plugs connected to equipment should also have an occasional combined inspection and test to look for faults. Combined inspection and testing should be carried out where there is reason to suspect the equipment may be faulty, damaged or contaminated, but this cannot be confirmed by visual inspection. Combined inspection and testing should also be carried out by the repairer after any repair or similar work to the equipment. Suggested intervals are shown below.

Equipment/environment
User checks
Formal visual inspection
Combined inspection & testing
Battery operated
No
No
No
Extra low voltage: telephones, low voltage desk lights
No
No
No
IT:
desktop computers, screens
No
2-4 years
No, if double insulated - otherwise up to 4 years
Photocopiers, fax machines: rarely moved
No
2-4 years
No, if double insulated - otherwise up to 4 years
Double insulated equipment: moved occasionally eg fans, lamps, projectors
No
2-4 years
No
Double insulated equipment: handheld eg some floor cleaners
Yes
6 months - 1 year
No
Earthed equipment: eg electric kettles, some floor cleaners
Yes
6 months - 1 year
1-2 years
Cables and plugs connected to the above.

Extension leads (mains voltage)
Yes
6 months - 4 years depending on equipment connected to
1 - 4 years depending on equipment connected to

Keeping records of the results of inspection and testing can be important, especially if an electrical accident later occurs.
 
Extension Leads

The use of extension leads should be avoided where possible. If used, they should be tested as portable appliances. It is recommended that only 3-core leads (including a protective earthing conductor) be used.

A standard 13 A 3-pin extension socket-outlet with a 2-core cable should never be used even if the appliance to be used is Class II, as it would not provide protection against electric shock if used at any time with an item of Class I equipment. Some equipment does not need testing such as battery-operated or extra low voltage equipment. Other equipment may not need testing but occasionally its lead and plug will. Some types of business equipment like computers, screens or printers can be damaged by inappropriate tests.

Only competent contractors should be employed to carry out electrical work in offices and libraries. The NICEIC maintains a Roll of Approved Contractors capable of safe, good quality work. By selecting contractors from the NICEIC's Roll, specifiers know that the required safety standards underwritten by the NICEIC will be met.