The entire electrical installation is controlled by this board which contains all the over current protection circuit breakers, Isolators and the earth leakage protection unit.

Each circuit should be neatly labeled so that it can be easily identified which is absolutely essential when determining where a fault has occurred:

 

When a ‘Socket outlet’ circuit breaker trips:

The instinctive reaction is to switch the breaker back on, however this is not a good idea as the fault may still be present and could be aggravated, possibly causing a fire, here is a less risky approach.

• Determine the area affected and unplug all appliances that are plugged into that circuit. Generally if the appliance has developed a fault, some evidence of the electrical “burn out” is visible by a telltale black sooty deposit.
• Switch the circuit breaker back ON. If it trips immediately, then the problem lies in the wiring and it is best to leave the breaker OFF and call your Electrician.
• If the breaker stays ON and no visible signs of a fault can be seen, then plug each appliance back into the circuit and switch it on, proceed with this until the circuit breaker trips again – that would then be the faulty appliance. However, some faults may have cleared themselves and the appliance works normally, in which case the breaker would not trip again, or the appliance is ‘open circuit’ and consequently does not work and also will not trip the breaker.

When a ‘Lights’ circuit breaker trips:

The same caution should be applied.

• Determine the area affected and switch OFF all the light switches in that area.
• Switch the circuit breaker back ON. If it trips immediately, then the problem lies in the wiring and it is best to leave the breaker OFF and call your Electrician.
• If the breaker stays ON, then switch each light switch back ON, proceed with this until the circuit breaker trips again – that would then be the light circuit. However, some faults may have cleared themselves and/or the globe has become open circuit, in which case the breaker would not trip again and the problem should be resolved by replacing the globe.
• Be mindful of any electronic devices such as ‘built in’ dimmers and timers which may have malfunctioned, in such a case, call your Electrician – do not attempt to repair or replace the wall switch assembly yourself.

When the ‘Stove’ circuit breakers trips:

The same caution should be applied:

• Switch the Stove and Oven (if separate) Isolator(s) OFF. Switch all the stove plates, oven elements and fans OFF.
• Switch the circuit breaker back ON. If it trips immediately, then the problem lies in the wiring and it is best to leave the breaker OFF and call your Electrician.
• If the breaker stays ON, then switch each plate, element and fan, individually. Should any of this cause the breaker to trip, then that would be the faulty plate or element. You could leave it OFF and proceed to use the other plates or elements whilst waiting for the stove to be repaired.

 

When the ‘Geyser’ circuit breakers trips:

The same caution should be applied:

• It is best to call your electrician or plumber, as it is not advisable to work on the geyser unless qualified to do so.

House wiring is generally ‘out of sight’ and mostly in plastic conduit. It is not advisable to interfere with this in any way for two reasons:

Safety:

Wires are conductors of electricity and are therefore dangerous when exposed and especially when the insulation has been damaged in any way.

The electrical circuits are often not easily recognized by exposing wiring at any point along the conduit installation. Any changes may alter the polarity to the appliance or outlet and increase the risk of reduced electrical protection to the user.

Certificate of Compliance (CoC):

All electrical installations would have been issued with a detailed COC, by the contractor that carried out the work and tested it, in accordance with the ‘Wiring Code’. Consequently any changes to the installation, by anyone other than a qualified Electrician, will render the COC null and void.

All socket outlets are rated at 16A and are protected by a 20A Circuit Breaker and also protected against earth leakage, by an Earth Leakage Unit. These two “sentries” generally protect you against electrocution and many causes of electrical fires in the house or office.

Another safety feature that has been fitted to each socket outlet is the Safety Shutter. This prevents the insertion into the Live and Neutral socket entry holes, by the action of a plastic component, which in some cases, may be operated by the Earth pin of the plug.

There are certain precautions that need to be taken:

• Check that the shutter works properly and does not expose any of the entry holes, other than the Earth one.
• Always switch the socket ‘OFF’ before plugging or unplugging an appliance into the socket outlet.
• Always check that the plug is not damaged in any way or the plug pins have dirt or any substance attached that could be transferred to the socket contacts, inside the socket outlet.
• When cleaning the socket outlet faceplate, use a soft soap on a slightly moist cloth; avoid water entering the socket outlet by way of the socket entry holes or the switch surround.

Although these are essential items for any home or office environment, they are arguably the most risky to use. The main reason for this is that a long length of electrical cord is loose, on the ground and over various obstacles. The mains voltage is separated from the environment by 1mm of soft PVC insulation.

This insulation can easily be, scuffed, shaved, punctured and sometimes cut by the most obvious events. The exposure of the inner conductors can cause injury, and electrical fires.

There a certain precautions that needs to be taken:

• From time to time, check the surface of the extension cord throughout its length; replace it if any exposed copper conductors are evident.
• Where the cord is used temporarily, ensure that it is not trodden on by arranging a “protective cover” over the portion exposed to traffic.
• Where a more ‘long term’ extension is required, ensure that the cord is fixed to the wall, out of the way of any traffic, by neatly spaced cable cleats of the correct size.
• Regularly check the state of the socket outlet and ensure that the shutters are operating correctly, check the plug pins for damage and adhesion of dirt and grime.
• Electrical cords near an open fire such as a braai area should be avoided and kept at a safe distance.
• When using an extension reel, ensure that the cable is fully ‘un-reeled’ as to avoid the increased heating effect caused by the inductance of a coil carrying current.
• Caution is advised on the use of the correct rating, especially for cord extensions that are rated at 10A, check the appliance that needs to be plugged into the extension cord, especially heaters, which could require currents around the 8A level, a 10m extension cord would not be suitable in such a case and one would be advised to use a shorter version or one rated at 16A.

Invariably there are many more appliances than socket outlets and the use of plug-in adaptors neatly solves this problem. Also, due to the different plug configurations that are not always found on the wall socket outlets, a multiple adaptor is essential.

South Africa has 9 Legal Plug and Socket configurations

These are:

SANS 164-1:

Plugs and socket outlets for household and similar purposes for use in South Africa –

PART1:
Conventional System, 16A 250V a.c.

The most common plug and socket in use in South Africa originated from the old British System BS 546, with some small differences in pin lengths. It has been in use for the past 80 years, metricated in 1953 and revised in 1980. Britain replaced this standard with the “flat pin” fused plug BS1363 in 1947.

SANS 164-2 Plugs and socket outlets for household and similar purposes for use in South Africa –

Part 2 :
IEC System, 16A 250V a.c.

In the 1980s SA decided to introduce the IEC worldwide plug and socket system, based on IEC 60906:1986, which had been under development by the international community from 1966.

Arguably the SAFEST system in the world the socket outlet is mainly used in SA due to the fact the it accommodates cell phone chargers and 2-pin EUROPLUGS fitted to small power devices such as hair dryers etc.

The main feature of its design is that the socket is shuttered and has a 12mm pocket which makes it impossible to touch a live pin during plug insertion:

SANS 164-2 also caters to a 16A, 2-pin system that is extensively used in adaptors and is intended for Class II appliances and power tools.

The standard allows the connection of an unearthed plug into an earthed socket but not vice versa – as this is a dangerous situation where an appliance that requires a protective earth, would be unearthed, which under fault conditions could cause fire or an electrocution.

SANS 164-3:

Plugs and socket outlets for household and similar purposes for use in South Africa –

Part 3:
Conventional System, 6A 250V a.c.

The 6A plug and socket has also been in use for the past 80 years, now used extensively for the connection of luminaries, in its non-rewireable form.

The 6A, 2-pin version has been dropped several years ago together with the 2-pin “flat-faced” socket which was commonly found on adaptors.

As plug circuits are rated at 16A and protected by a 20A circuit breaker, this system fell out of favour for fixed installations.

SANS 164-4: Plugs and socket outlets for household and similar purposes for use in South Africa –

Part 4:
Dedicated System, 6A 250V a.c.

Dedicated systems are used for the connection of equipment such as computers to special power supplies that have uninterruptible or “clean power” characteristics, either from a special transformer or a battery/inverter system that takes over in the case of a power failure.

The dedicated earth pin has 3 possible types, determined by the rotational position of the flat portion: i.e
– 53o BLACK
0oRED and
+53o. BLUE

Colour nomenclature is also an integral requirement
The main advantage of this system is that the dedicated plugs cannot be interchanged (within the dedicated configurations) but may be inserted into the standard (non-dedicated) system – SANS 164-1.

SANS 164-5: Plugs and socket outlets for household and similar purposes for use in South Africa –

 

Part 5:
Two-pole, non-rewireable plugs, 2,5A 250V a.c., with cord, for connection of class II equipment.

A 2,5A plug of the EUROPLUG design has smaller diameter contact pins than those in the 16A (SANS 164-2) version.

And is extensively used in cell phone chargers. It is compatible with SANS 164-2 and SANS 164-6, both standards make provision for contact integrity between the two pin sizes. However, because of the compatibility of plugs of a higher current rating, a 2,5A socket has not been allowed for obvious reasons.

SANS 164-6: Plugs and socket outlets for household and similar purposes for use in South Africa –

 

Part 6:
Two-pole, systems, 16A 250V a.c., for connection of class II equipment.

The Schuko system, which is common to many European countries, has been the subject of many heated debates to the point where the Minister published a mandatory prohibition on the use of the earthed plug (VC8008: 1994). The main reason lies in the fact that many unearthed 2-pin adaptors will accommodate an earthed plug, with potentially dangerous consequences. A 2-pin (Earthed and Unearthed) socket is allowed in adaptors and also in fixed installations. The standard is taken from CEE 7/17 and the use of this plug is limited to a non-rewireable type

In accordance with the ‘Wiring Code of practice’ Each permanently connected (fixed) appliance must have a Switch Disconnector (isolator) within arm’s reach of the appliance, which disconnects both Live and Neutral supply to it.

The Isolator is usually rated between 30A and 60A depending on the stove rating and in certain applications may be 3-phase.
This is a safety measure and should be switched off whenever the stove or oven is being cleaned, or in the case where maintenance of any kind is undertaken.

There are certain precautions that need to be taken:

• always switch the isolator ‘OFF’ when cleaning the stove or oven.
• When cleaning the isolator faceplate, use a soft soap on a slightly moist cloth; avoid water entering the isolator through the isolator surround.

Connection to Dishwashing and Laundry Machines: These handy appliances generally use high currents to operate, sometimes for short times, during their programmed cycles.

Currents between 8 and 12A are quite common and although the wiring is perfectly adequate for this, one often is tempted to combine these machines on one plug by using a cord extension or a plug-in adaptor.

There are certain precautions that need to be taken:

• Always use a cord set with a 16A rating.
• Avoid the use of plug-in adaptors, if absolutely necessary; use only a ‘double adaptor’ which is rated at 16A.
• Avoid, wherever possible, using two or more machines at the same time.

Special arrangements are made in the pump housing in terms of the Wiring Code;

• The Pump and control-gear installation must be on or beyond zone 2 which is a minimum of 2m from the pool’s edge.
• The Control box must be of suitable IP protection rating.
• The Pump must be supplied via an Earth Leakage protection unit with a maximum tripping current of 30mA.
• The pool lighting is to be supplied via an isolating transformer with 12V maximum output to the light.

It is most important to the safety of you and your family that NO 220V appliances are brought close to the pool, or used in its vicinity.
The pool timer is usually set at different schedules for summer and winter, typically with manually chlorinated pools:

Summer: – ON from 8am to 4pm (8 hrs.)
Winter: – ON from 9am to 3pm (6 hrs.)

Light switches are touched most often and require very little introduction, however some care needs to be taken in the daily use:

• Press the switches evenly and without undue force.
• Do not hit switches with force or hard objects. Remember that the plastic is your protection against contact with electrical current.
• Do not splash water or any liquid on the switch.
• To clean, use a damp cloth with a little soap and wipe off any residue with a dry cloth.

Dimmers:

Although most modern light dimmers are capable of dimming various light sources such as Compact Fluorescent tubes and LED’s, not all lamps are dimmable, so take care when purchasing lamps for replacement, that the product is marked as “DIMMABLE”.

Some dimmers are not capable of dimming anything other than incandescent lamps – in this case the lamp may flicker, stay on one setting or not light up at all.
This is especially the case with LED lamps; these generally require a special type of dimmer to enable suitable dimming.
Dimming of fans or any other appliance: This is generally not possible and could lead to the dimmer failing. Fans are normally fitted with a 2 or 3 speed controller, which should be used without adding any other component (such as a dimmer).

Where small appliances such as hair dryers, curling tongs and cell phone charging occurs, one usually finds the small two-pin “Europlug”. It is a good idea to have sockets of the SANS 164-2 configuration fitted in addition to the well-known SANS 164-1.
Currently there are several products available on the market that combines these two configurations as this example:

This is a better alternative to the use of adaptors and cord extension sets, often lying on the floor or carpet.

It is also good practice not to have small appliances plugged in with the power ON whilst not in use; these should be packed away safely or switched off at the socket outlet.

Common to most Lounges and TV rooms, where entertainment systems are in use, the common socket outlet is usually inadequate to supply the various devices. Cord extension sets with many sockets and different configurations are mostly used, these are untidy and often quite dangerous; the devices are usually switched on STANDBY and draw a continuous, although small, current.

It is good practice to do the following:

• In the planning of a new house or installation, chose a ‘cluster’ type multiple socket-outlet which should be fitted behind the entertainment structure or alcove.
• Fit a simple ‘power monitor’ which monitors the main device (say TV set) and it that is off, then it switches off all the other devices.
• Avoid adaptors as far as possible.

Surge Suppression: It is also a good idea to have some form of surge suppression in two ways:

• In the Main Switchboard – this protects the entire installation, referred to as a level II protection, is quite useful but still allows some surges to enter the installation.
• As close as possible to the equipment – this protects the equipment, referred as level III protection, it limits the voltage surge to a lower value and is found in several products such as plugs and cord extension sets.

There are some points to be aware of:

• The surge protection device may reach the end of its useful life by having had dealt with several surges, in which case it will by internal design, be rendered inoperative – this is an important design feature since at the end of their useful life, surge arrestors of the metal oxide varistor (MOV) type, become dangerously hot to the extent that they can ignite.
• Monitor the warning light on the MOV protected product and replace it when this changes state as per the instruction legend.
• Ensure that the protection device complies with the SA standards (SANS 60884-2-5 or SANS 164-0 or SANS 1661, VC8008 or VC8029).

Under-floor heating elements are usually fitted at the construction phase of the premises and also under tiles, wood flooring or carpeting. This heating element is connected to the mains via a double pole isolator and a temperature controller of which there are two basic types:

Electro-mechanical: comprising of a bimetal thermostat that measures the air temperature, a graduated rotary setting to select the desired temperature and a relay to switch the power to the heating element under the floor.

Electronic: which also has the relay but the temperature controller is a small microprocessor with a solid-state thermal measuring device. The temperature setting is done digitally and the display is usually a small screen or numerical display.

It is generally not recommended to use the air temperature measurement method to control the under-floor heating but rather to make use of temperature sensors fitted into the floor close to the heating element. In this way the actual floor temperature is measured rather than the air above it.