The home lighting system consists mainly of lighting circuits devoted to supplying fixed lighting only. Other lighting is sometimes termed auxiliary lighting, but in some rooms this may, in fact, constitute the main lighting.
Auxiliary lighting comprises spot lights, pelmet lighting and other special lighting and effects. Read the rest of this entry »
Small table cookers and other portable appliances having individual loadings not in excess of 3 kW are run off 13 A fused plugs and socket-outlets. They require no special wiring though extra socket-outlets may be needed in the kitchen when additional electrical cooking appliances are bought. These additional socket-outlets may be served from the ring circuit and spurs.
Family-size cookers, whether free-standing or built-in split-level, need an exclusive circuit from a fuseway of appropriate current rating. Read the rest of this entry »
Where the white meter tariff is in operation it can be an advantage to heat the full contents of a tank overnight when the cheaper rate for electricity is in force and switch on the short element wizen additional hot water is needed.
This normally requires two circuits for the immersion heater installation. One circuit is used for the night rate supply, when time controlled in conjunction with night storage heaters, this supplying the long element of a dual immersion heater or the lower immersion heater of a two- immersion heater arrangement. Read the rest of this entry »
Formerly imperial ratings were used for fuses and circuit breakers, but the international Renard ratings have now been added and will supersede them.
Fuse manufacturers are still using the imperial sizes while circuit breaker manufacturers have mostly changed to the new ratings. An equivalence chart is shown above.
The miniature circuit breaker (MCB) is now widely used and overcomes all the problems associated with ordinary fuses. It is a small, sophisticated unit affording a much higher level of protection than an ordinary fuse. It is tamper-proof and the unit involved is easily identified when one has tripped (the switch moves to the ‘off’ position). Most importantly, MCBs cannot be reset if the fault still exists; this eliminates the foolish and highly dangerous practice of putting in the wrong fuse wire or cartridge just to get things ‘conveniently’ working again for the time being. Read the rest of this entry »
A basic understanding of electricity is essential, even for those who do not intend to carry out any repairs or servicing of appliances. Ignorance is no protection against your own or someone else’s errors and oversights, whether with repairs, servicing or installation.
Power is supplied to an electricity substation at a very high voltage — 400,000 volts — in three-phase form. There it is converted, via a transformer, to 230 volt single-phase for distribution to our homes. In normal circumstances, current flows from the live supply of the substation’s transformer, through the electrical appliances used in the house and back via the neutral conductor (cable) to the substation transformer’s neutral pole (a closed loop). Read the rest of this entry »
A huge variety of household appliances contain heating elements. The two basic types are the exposed single-wire element, most often used in hairdryers, fan heaters and toasters, and the metal-sheathed element used in ovens, grills, iron sole plates and immersion heaters.
This type of element is simply an exposed length of conductor which heats up when a current is passed along it due to the resistance properties of wire. As it is an exposed conductor, it must be housed and supported in a way that avoids accidental contact which could cause electric shock or burns. It must also be housed in a way that allows the heat generated to dissipate and do the job intended. For instance, a toaster needs a large aperture in which to place the bread so that it rests near the exposed element for it to function correctly. Read the rest of this entry »
Most labour-saving household appliances contain an electric motor of some description. They are the workhorse of these appliances and most of them are capable of coping with the work loads inflicted upon them. However, some motors, either through poor design or as a result of manufacturers’ cost limitations, are inadequate for the job they are required to do. Adequate or not, at some point it is almost inevitable that they will fail or simply wear out. To delay this, use the appliance with some care and attention, be aware of its limitations and carry out regular inspection and servicing. This will prevent small problems escalating into major ones
Not only do the sizes of motors vary greatly between products, so too do the ways in which they work. To diagnose faults successfully and service or repair appliances, a working knowledge of motors is essential. The following provide a basic introduction to the various types, a description of how they work, the appliances in which each may be found and their particular advantages and drawbacks. Specific problems can be found on individual appliances. Read the rest of this entry »
