Although the primary purpose of a lighting fitting is to provide light, a fitting is exposed to view throughout the hours of daylight and it is, therefore, equally important that it is pleasing to look at when not alight. Before buying a fitting decide whether you would prefer a ceiling fitting or wall lights. If you decide on a ceiling fitting choose between a pendant or a close- mounted ceiling fitting.
Also, decide on the position of the fitting as this will also affect the choice. When choosing in the shop or department store try and visualise how a fitting would appear in your home. This is not easy when the shop has a forest of fittings, some alight and others unlit. 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 »
Capacitors used for motor starting may have metal or plastic outer casings with an insulated top with two terminals. Internally the two terminals are connected to two sheets of metal foil with an insulator between. This package of large surface area is rolled into a cylinder which fits into the shell of the capacitor. As the voltage supplied to one terminal is alternating (at 50 times per second), so does the polarity of its connected foil. An opposite movement of electrons is induced in the other foil, even though they are insulated electrically. This causes a delay in the electrical path, and this, in the case of an asynchronous induction motor, gives the outof-phase feed to the start winding. Read the rest of this entry »
Aschematic diagram of the internal workings of a pod-type thermostat. This type is used in appliances that have a variable temperature control. It consists of an oil-filled pod connected to the switch by a capillary tube. When the oil in the pod is heated or cooled, it expands or contracts in the tube and operates a diaphragm. The diaphragm acts on the switchgear thus breaking the circuit and in this instance, ‘making’ the other. The cooling oil contracts, pulling the switch the opposite way — back to its original position; the process repeats if temperatures change. Read the rest of this entry »
Isolate the appliance before removing covers or panels for any reason. All tests for continuity should be carried out with a battery operated test meter only.
The most likely cause of overheating will be a failure of the thermostat contact points or sealed pressure system. In such a case you will need to fit a new compatible replacement unit.
Slow initial heating-up times or uneven heat distribution within the oven is usually caused by the failure of one element. Simple testing of the element will highlight the faulty item.
Failure to heat up at all may be either the thermostat or elements. As elements are the easier of the two to check for continuity, a simple process of elimination will indicate where the fault lies. Read the rest of this entry »
The information given here also applies to the grills on many cookers. This is a simple way to ascertain if the control is faulty. Short circuit failures on elements may damage regulators in which case, if you are in any doubt, renew it.
The following test is for a single circuit application, that is, a single element. For double regulators, that is, a double element, the same procedure will be required on both single and double operations of the switch. From off position an anticlockwise turn will put into circuit one element (usually the inner), a clockwise turn from the off position will put into circuit both inner and outer. Check that double regulators operate independently on a half turn each. For singles, use ony a full turn. Read the rest of this entry »
The brush roll is supported on bearings at each end so the barrel rotates freely. Types of bearings, barrels and brushes differ from model to model as well as between manufacturers. Some manufacturers supply individual parts for the brush roll, such as brush strips, bearings and barrel; others supply only complete assemblies. The brush roll on some models may have removable brush strips, whereas others may be a solid brush roll of wood or plastic with fixed brushes. A small selection is shown here to highlight the differences. Read the rest of this entry »
The upright style of vacuum cleaner is perhaps the best for large areas of carpet. It is especially good at removing dirt embedded within the pile and pet hairs from the surface, even on sculptured carpets. A drawback with the basic upright cleaner is its difficulty with cleaning stairs. The problem has been overcome with the modern combination of upright and cylinder cleaner. This type may be the best option if you have large areas of fitted carpet and staircases. The motor within the upright cleaner creates the airflow (suction) and drives a rotating brush roll, often called an agitator barrel. Read the rest of this entry »
The domestic vacuum cleaner has been with us now for some 90 years, during which time it has become the most popular labour-saving appliance in the home. The basic principle of operation is quite simple. An electric motor drives fans to create a fast-moving air flow. At one end, a vacuum (suction) of air is created, while at the opposite end the air is exhausted. If the air is moved quickly enough at the inlet end, it will carry with it any debris that enters the airflow. A means of removing the debris from the airflow is required to prevent its redistribution as the air is expelled. Read the rest of this entry »
Cord rewinds are now found on all types of cleaners, from simple hand-operated versions to the fully automatic rewind at the touch of a button. Many auto cord rewind systems use open coil springs and great care should be exercised if a stripdown of these systems is called for. Protection for the eyes is recommended. Goggles afford adequate protection from the spring itself or any item that it may throw out in the event of its slipping from position.
Operation of the cord rewind relies on tensioning of the rewind spring as the cord is pulled out for use. A small brake pad prevents the immediate return of the spring and cord drum to its original position. Read the rest of this entry »
