maintenance of domestic appliances

1. Radio

A radio is an instrument used to receive messages without wire connections but through electromagnetic waves. The various types of radio sets in our homes are made to serve the same purpose, namely to receive information such as music for our entertainment news, both local and foreign; religious, political and social discussions.

Care of the Radio

1. Dust everyday with soft cloth.
2. Clean delicate parts gently.
3. If the radio is battery-operated, remove the battery cells whenever they become dead. Do not allow dead batteries to become rotten inside the radio.
4. Do not tamper with components or electrical parts. If there is any fault, take it to an experienced radio technician.
5. CD/DVD Music Player

A CD/DVD player is an instrument designed to play CDs, DVDs and supply music for entertainment or for enjoyment.

Most CD and DVD players are made to use only electricity. This type is used in places where there is electricity supply. Some players use only flashlight batteries and can be used in rural villages without electricity supply, as well as for outings such as picnics. The most recent record players use both electricity and flashlight batteries. Others have radio attachments built into them, e.g. loudspeakers and cassette recorders.

1. Maintenance of the Music Player

Read through the instruction manual thoroughly. The directions in the instruction manual should be followed strictly.

Most record players have double speed, e.g. 33rpm and 45rpm. Always select the correct speed for any particular record. Clean record pins should always be used, and should be changed as soon as they go bad.

1. Care of the Music Player

A record player has many delicate parts and should be used with great care. The tone-arm should be handled with care. Check the power source, the correct speed of the record before playing. If batteries are used, remove them as soon as they are dead. Always check record pins for dust, which must be removed carefully using a special soft brush.

Dust the record player from time to time with a soft brush. In case of fault, take to the maker or an experienced radio technician.

1. The Refrigerator

A refrigerator is a device for keeping food item cool. It is used to preserve food items such as meat, fruit, fish and vegetables for a short period of time. It also has a section called a ‘freezer’ which is used for freezing food. Frozen foods can be preserved for a much longer period of time e.g. weeks, months and even up to a year.

The design of the refrigerator is such that it has many shelves and fittings for proper storage of food items.

Most refrigerators use electricity as their source of power. Others use gas or paraffin. They come in various sizes, from the giant commercial types of medium household sizes, down to the dormitory sizes.

Care of Refrigerators

The instruction manual which comes with the refrigerator gives the detailed instructions on how to use and care for the refrigerator. It should be followed strictly.

1. Arrange food items in the refrigerator properly so that air can circulate all around and keep them cool enough avoid their getting bad easily.
2. Always cover milk and butter very well because they can easily absorb odour from other strong scented foods.
3. Check the refrigerator regularly for any spoilt food which must be removed immediately.
4. Wipe the inside with damp cloth, using bicarbonate of soda as detergent. Do not use soap or other detergents as they may leave undesirable odour inside.
5. Wash occasionally; both inside and outside of the refrigerator.
6. Thick frost reduces the cooling effect of the refrigerator. So defrost the refrigerator once a week or as soon as the frost has become about 13mm thick in the freezer. When the ice has melted, clean the refrigerator and dry properly.

A refrigerator usually becomes faulty due to the exhaustion of the refrigerant. The refrigerant is the fluid which flows in the coil to keep the inside of the refrigerator cool. Hence, such faulty refrigerator does not keep food cool. If this happens, there must have been a leakage, in such a case, call an expert who will locate and eliminate leakage and then recharge the refrigerator with the appropriate refrigerant.

1. Pressing Iron

Pressing iron is used to keep the surface of the clothes we wear smooth and straight; that is, to remove the rumples from washing or rough handling. Different types of iron are in use in Nigeria. In villages, where there is no electricity supply, they use (a) Flat iron (b) Box iron or coal and (c) Tilley iron. In places where electricity is available, people use electric iron or steam iron for pressing their clothes.

1. Types of Iron
2. Flat iron:Flat irons are heated with charcoal fire or wood fire. It is advisable to use them in pairs, while one is in use, the other is being heated. This makes it possible to have a continuous pressing exercise. The handle of a flat iron is made up of iron and wood. The body of the iron is heated along with the handle. It is important that we have a well stuffed small pad to hold the hot handle always.

When a flat iron is heated, the whole body becomes hot and smoky. The smoky body should be cleaned properly with a clean cloth.

The bottom surface should be rubbed on sand or powdered bath brick to keep it clean. Finally, it should be thoroughly cleaned with a clean cloth. A flat iron should stand on a metal strong enough to prevent scorching the sheet and large enough to keep the iron from slipping off.

1. Box iron or coal iron:The box iron or coal iron is generally made of cast iron. To use the box iron, it has to be stuffed with charcoal fire and allowed to heat up properly. The box iron has a lock, which must be locked very well before use, otherwise the lid may suddenly open while using the iron, and charcoal fire pours out on clothes and sheets and burns them.

Before starting to iron clothes, the bottom surface of the box iron should be cleaned with a clean cloth, Ash should be blown out from time to time from the box iron and the body rubbed over with waste material. Like the flat iron, it should be kept on a strong metal to avoid scorching the sheets and large enough to keep the iron from slipping off.

1. Tilley iron:This uses paraffin or kerosene to get its heat through a tank and a pump attached to it. When kerosene is poured into the tank and pumped properly, heat flows from the iron sufficiently to make pressing possible. It has nothing to regulate the heat. Always stand the iron on an end when not in use.

Gas iron: Recently, the gas iron has appeared in the market. It has an adaptor that hangs from the iron and connected to the gas tank. When the gas tank is opened, gas flows into the iron through the adaptor. When the burner is lit, it supplies sufficient heat to press clothes. One disadvantage is that it has nothing to control the heat, as in the case of the electric iron.

1. Electric iron:In towns and villages where there is electricity, people prefer to use electric pressing irons than any of the types already mentioned. This is because the electric iron is very simple to use. To use, fit in the plug into the outlet socket and switch on, then select the appropriate heat for the type of material being pressed.
   f. Steam iron:This uses electricity as its main power source and can be used dry. ‘Dry’ here means, using the pressing iron as an ordinary electric iron, without putting any water. ‘Steam pressing’ is achieved by pouring water into the iron. The water is heated and the steam produced is forced through the vents.
2. Air-Conditioner

Air-Conditioners are appliances installed in homes, offices, cars, surgery rooms in hospitals and other places for cooling, while also protecting the space from dust.

Air-Conditioning appliances are always equipped with connections for air intake and exhaust. For this reason, they have to be installed through walls or windows. The best location for then is where they will receive no direct sunshine. Air-conditioners come in different sizes. People should always get the correct size for the rooms they are to be installed into.

Types of Air-Conditions

Air-conditioners have powerful fans, which draw in air from outside by suction through filter, which purifies the air. It is then cooled by the heat exchanger and the cooled fresh air circulates to every corner of the room. Most air-conditioners have a thermostat, which keeps the temperature constant at required level. Others have temperature control switches, which enable the individual to select the room temperature he or she wants. It is equally possible to make the air-conditioner fan the room without actually cooling it.

All the doors and windows must be closed when the air-conditioner is one.

Care of Air-Conditioners

1. Always operate an air-conditioner according to the maker’s directive.
2. After a period of use, the air-conditioner collects a lot of dust. Switch off at the outlet socket and use soft cloth to dust it all over.
3. In case of a mechanical fault, refer to the maker or an experienced air-conditioner repairer.
4. Fan

A fan is a device or an instrument which rotates when switched on giving a current of air for ventilation. Three types of domestic fan, are available; the table fan, the standing fan and the ceiling fan. A table fan is normally put on the table, where it can easily rotate when it is switched on and supply current of air to the room. A standing fan is usually kept standing in a convenient corner of the room. A ceiling fan is installed hanging down from the ceiling. The switch box for operating the ceiling fan is usually installed on a wall. Each of these fans mentioned above has blades, a a control box to switch off and on and to control speed.

The table fan and the standing fan have a guard to cover and protect the blades.

Care of Fans

1. Use fans according to maker’s instructions.
2. Whenever the fan is not needed, it should be switched off.
3. To clean the fan, open the guard and dust the blades and every other part. First dust, then clean with a damp cloth and dry very well.
4. Whenever the fan has any mechanical fault, an experienced technician should be invited to do the necessary repairs.

Electric Kettle

An electric kettle uses electricity as its main source of power to boil water. Most electric kettles are made of aluminium, and have well-insulated handles, knobs and bases. The lid is very well secured so that it cannot easily drop or fall out. The kettle is also well vented for the escape of steam. A safety cut out or a warning device is fitted to indicate that boiling is complete.

1. Care of Electric Kettle

New kettles, if made of aluminium, should be boiled out for 10 minutes, adding one teaspoonful of borax to each litre of water.

This prevents the formation of discoloration due to water which should not be allowed to standing an electric kettle for a long time. In hard water areas, kettle ‘fur’ should be periodically removed by a removing agent. After use, an electric aluminium little should be cleaned with a nylon scourer used with fine abrasive powder or paste or fine steel wool softened with soap.

1. Uses of Other Aluminium Kettles

The use and care of other aluminium kettles which can be for boiling water on gas cookers or paraffin or kerosene stoves are just the same as in electric kettle.

The only difference is that paraffin or kerosene cookers very often produce smoke which stains the kettle. So, a little more pressure or force is required to wash the kettles clean with the same kitchen abrasives.

Radio Maintenance (General Maintenance)

1. Switch off the mains, and clean the framework with a dry soft cloth, brush or duster. Avoid cleaning plastics with petrol.
2. If battery-operated, remove the cells, and the clean the contact with an emery cloth, dry-clean the battery compartment, and replace the cells correctly, ensuring good contact.
3. Turn the radio upside down with the cover removed, or blow compressed dry air to remove insects and unwanted particles.

Faults and Remedies

1. Volume not being high: Clean the volume control switch with a liquid cleaner, or replace the volume control switch.
2. Cracking noise: This may be corrected the same way.

Intermittent Failure:

Partial contact of the mains connection may be the cause. Check the plug or switch contact and ascertain good contact.

Maintenance of Cassette Tape Recorder:

1. Clean with a dry clean duster or brush when in ‘off’ position.
2. Clean the battery compartment, cells and contact terminals as in the case of the radio.
3. Clean the recording and play head with clean soaked in methylated spirit or pure alcohol.
4. Clean capstan rollers with the same clean cotton, and dry off quickly by blowing excess spirit off.
5. Remove insects and unwanted particles, as in the case of the radio.

Faults and Remedies

Sluggish motion: The fault could be due to a faulty motor, poor belt tension due to expansion, rubber belt, or worn out capstan.

Change the motor if cleaning/oiling of shaft fails to correct the speed. Clean the belt with spirit and apply chalk dust to increase the friction or change and replace the capstan rollers.

Maintenance of Television Set

General Maintenance

1. Switch off, and remove connections to the mains by removing the plug (isolate).
2. Clean as in the case of the radio.
3. The induced voltage developed at the rear side of the television from its output transformer is more than 10KV. This is many times the supplied voltage, it is advisable for students to carry out repairs under the supervision of their technical teacher in order to avoid severe electric shock, which is even possible when the T.V. is off.

Faults and Remedies

1. Total failure: Check the fuse in the plug if electricity supply is still on in the room.
2. Picture continuing to roll up or down: Adjust the vertical hold knob at the back or side of set marked ‘V. Hold’.
3. Appearance of dark broad lines on screen: Adjust the horizontal hold knob marked ‘H. Hold’, or switch off for a few seconds and or again.
4. Appearance of ‘ghost pictures’ or double image: Adjust the aerial until the picture becomes a unit.
5. Absence of pictures, presence of rasters on screen: Relocate the position of the aerial; other components in the television may cause this fault.

Maintenance of the Pressing Iron

The general maintenance operations for the different types of pressing iron (electric, coal-pot, gas, tilley, steam, etc.) have been covered previously. You are advised to make a quick reference to the materials presented in that unit. Here, we shall detect the method of fault detection when an electric iron fails to heat up. If there is a total failure and the fuse in the 13A plug is intact, check with an insulation and continuity tester, e.g. a ‘megga tester’ for continuity between the life (L) and neutral (N) terminals in the iron. An open circuit (i.e no current flow) indicates a broken element or permanently open thermostat contacts.

Fault and Remedies

Failure to heat up: Open up the iron and test separately (a) the thermostat (b) the element. If the element is open circuited, change it.

Maintenance of Rotating Appliances

Rotating appliances which are powered by electric motors for their operation include table fans, ceiling fans, extractor fans, grinders, liquidizers, food mixers, hair dryers etc. The basic principles of operation of these appliances have been covered earlier.

Faults of Fans

Possible faults are as follows:

1. lack of electricity supply at motor terminals
2. Humming of fan motor, i.e. inability to rotate or tendency to rotate very slowly.
3. Noisy rotation (if table type) of fan walking i.e fan altering position.
4. Overheating