Electricians in London

Electricians in London

Security for homes and gardens

Home and Garden Security

burglar

How secure is your home and garden ?

The use of technology to improve burglary prevention is the cheapest way to deter thieves.

Security equipment such as CCTV, will not only help police catch the burglars , but in most cases it will help prevent the crime from happening in the first place.

“When burglars realise the home or garden they’re breaking into might is covered by cameras they will think twice before breaking in.”

Fences, Gardens, Sheds and Garages

In London, the fence around your property is the first line of defence.It should send a strong signal that the house and garden is well protected. Most burglars are lazy and opportunistic, and they will look for an easy target.

razor spikes

Building walls over 2 meters high with razors spikes is one solution, or you could use a prickly natural hedge by planting Creeping Juniper , Firethorn and other plants to form an impenetrable fence.However, if the burglar gets past the fence, it will hide the criminals from view. This is when security technology comes in.

Security Lights, Security Cameras, Security Alarms

Installing a Security Alarm should be a priority. Security Lights are easy and cheap to install. Security Cameras are not expensive to install, there are many CCTV systems to suit any budgets.

security light camera cctv
This security light is also a surveillance camera, sensor – motion activated

Home theatrical experience

Having a Home Cinema experience, or a private cinema, using the latest gadgets in 1920, has been replaced by radio and TV.

Home theatrical experience in 1920

home theatrical

The Electrophone enabled people to listen to theatrical performances, concerts and church services from the convenience of their own home. This advert includes a postcard for potential customers to cut out and send off for more information about the Electrophone. Under the heading ‘Magic of the Sick Room’ it describes how the Electrophone can even relieve ‘the tedium of illness’
Basically it was a phone line.

Dealing with old Blown Circuit Fuses

If a fuse blows or an M.C.B. trips, cutting off the lights or power in part of the house, turn off the mains switch at the consumer unit and trace the device concerned. This is easy if you have M.C.B.s: the switch will simply have flipped into the “off” position and can be restored to the “on” position as soon as the fault has been rectified. In the case of fuses, there should be a list on or near the consumer unit showing which device controls which circuit.

If there is no list, then you will need to remove and examine in turn each fuse with the same rating as that of the affected circuit. For example, if a lighting circuit cuts out, then you should check the 5 amp fuses. Where a power circuit cuts out, check the 30 amp fuses – 20 amp if you have radial wiring. Individual appliances such as electric cookers, immersion heaters and night storage heaters will have separate circuits, each with a fuse at the consumer unit. Bear in mind that a cartridge fuse, unlike a rewirable fuse, usually shows no visible signs of damage: it must be checked with a continuity tester.

Before repairing or replacing a fuse, you should try to find out why it blew. Usually, the cause will be obvious. If a fuse blows immediately you switch on a light, then there is probably something wrong with either the bulb or the flex. If a fuse blows after you switch on the light, this could be a sign that the fuse wire has deteriorated with age and is no longer capable of carrying its rated current. However, if the fuse is of the cartridge type, which does not deteriorate, there is probably a fault in the wiring. A ring final circuit fuse will blow only through serious overloading or, again, because of a fault in the wiring. If there is a fault in an appliance, this will usually blow the plug fuse, leaving the circuit intact. Where you suspect that the wiring is defective, call in an electrician. Never try to solve a wiring or an overload problem by upgrating the fuse: the circuit could become dangerously overheated.

Old Fuses and Circuit Breakers

Fuses and Circuit Breakers

old electrics

From the electricity meter, the current passes to a consumer unit with an integral mains switch, or, in older installations, to a fuse board with separate switches and fuse boxes. The power is then transferred to the wiring circuits either by means of individual fuses or by circuit breakers. Either type of device serves an essential safety function. If a fault or an overload results in more current flowing through a circuit than it is designed to carry, the fuse will melt or the circuit breaker will open, thereby cutting off the circuit from the mains supply.

In this way, the excess current is prevented from generating the kind of heat that usually causes a fire. Miniature circuit breakers (M.C.B.s) are more convenient than fuses, which have to be repaired or replaced after a circuit interruption. Once the cause of the interruption has been corrected, a circuit breaker is simply reset by pushing the switch or button to the “on” position. M.C.B.s are a fairly recent development, however, and most electrical installations are still protected by fuses. These are of two types—rewirable and cartridge—and they are housed i n porcelain or plastic fuse holders which plug into the fuseways of the consumer unit or fuse box. Plastic holders are usually colour coded according to their current rating: 5 amp is coloured white, 15 amp blue, 20 amp yellow, 30 amp red and 45 amp green. The most widely used of the two fuses is the rewirable type, in which the fuse element – a piece of thin wire—is held in position by a screw terminal on either side of the holder.

If a fuse blows, melting the wire between the terminals, first the remnants of the old wire are removed and then a new piece of the same current rating is fitted in its place. In the case of the cartridge fuse, the element is enclosed in a small, metalcapped tube which slots into two spring contacts on the holder. The disadvantage of a cartridge fuse is that it cannot be repaired; once it has blown, it has to be replaced . It is also more expensive to replace than the rewirable type.

On the other hand, cartridge fuses come in different sizes according to their current rating, so that it is impossible to fit, say, a 20 amp fuse into a 5 amp holder. Like plastic fuse holders, cartridge fuses are colour coded so that they can be easily identified. The most important advantage of all is that a cartridge fuse provides greater protection for the circuit than a rewirable fuse. This is because i t takes less excess current to blow the cartridge fuse. For example, i t would need only 45 amps to blow a 30 amp cartridge fuse compared to about 60 amps for a 30 amp rewirable fuse.
In addition to protecting the circuits in your home, fuses and M.C.B.s perform another and all-important safety function. Because fuses can be removed and M.C.B.s switched off, they enable you to ” kill” a circuit so that you can work on it without the risk of receiving a shock.

Old electric meters

Old electric meters includes a small disc which revolves a certain number of times for every kWh (kilowatt-hour) or unit of electricity consumed. The disc operates, in turn, numbered indicators to register the amount of current used. Some meters have digital dials that resemble the milometer of a car, and they are read in the same way. More common, however, is the clock-type meter with five separate dials, each of which supplies one digit for the reading.

old electric meter and fuse box

The lower dial, which is red, shows fractions of a unit and is used only for test purposes. The left-hand dial registers tens of thousands, the next thousands, and so on to the right-hand dial, which registers single units. The numbers on the dials are arranged alternately clockwise and anticlockwise, and the pointers on the dials move accordingly.

When taking a reading, start with the left-hand dial and work across to the right of the meter. If a pointer is between two numbers, always take the lower number. If a pointer is directly over a number, the clue to a correct reading is provided by looking at the adjoining dial, as explained in the example on the right. To check your electricity bills, as you should periodically, make two consecutive readings and subtract the first from the second to calculate the consumption for the intervening period.

Take each reading on the day the official from the Electricity Board calls to make his own reading. Then compare your results with the figures on the second bill.

How can you check if your meter is working accurately?

The simplest way is by making use of the red dial, which measures 0.1 (or 1/10) of a unit. First, switch off a l l electrical equipment in the house and make sure that the rotating disc is stationary. Note the position of the pointer on the red dial and then switch on a load of 1 kW—for instance, of a 1 kW electric fire. If the meter is working accurately, the pointer should make one revolution—equivalent to one whole unit – in an hour.

The Multiple Pathways of Electric Current

Old wiring

Electricity generated in the power station comes into your home at 240 volts and is transmitted by a service cable which terminates in a sealed unit containing the Electricity Board’s service fuse. This is generally rated at 100 amps, but 60 or 80 amps is possible in older houses. This fuse provides a last defence in the unlikely event that your own fuses or M.C.B.s (miniature circuit breakers) fail to operate.

From the sealed fuse unit, the current passes through a meter, which records the amount used, and flows on through a consumer unit. This incorporates the fuses or M.C.B.s for all the house circuits. The cables of these circuits convey the current from the consumer unit (or, in older installations, the fuse board) to lights, switches and socket outlets. Each circuit has a specific current rating determined by the maximum load it is expected to carry. There are four standard current ratings—5 amps for lighting, and 15, 20 and 30 amps for power. A fifth rating—45 amps—has recently been introduced for “electricaire” central heating units and large electric cookers. Each of the two principal types of circuit— lighting and power—may be based on one or other of two wiring systems.

• RING FINAL CIRCUIT WIRING. In houses wired since 1947, most or all of the power is supplied by a ring final circuit— so called because the circuit is wired in the form of a continuous ring starting and ending at a single 30 amp fuse or M.C.B. in the consumer unit.

A ring final circuit can supply any number of 13 amp socket outlets and fixed appliances, provided only that the total floor area covered by the circuit does not exceed 100 square metres. In addition, branch cables called spurs may be run from the ring cable to supply socket outlets in remote positions—for example, a loft or basement. The number of spurs must not exceed the number of socket outlets and fixed appliances connected directly to the ring, and each spur may only supply one single or one double outlet. A spur is connected to the ring cable at the terminals of a ring socket outlet or at a 30 amp joint box inserted into the ring.

RADIAL WIRING. As with a ring final circuit, the function of a radial power circuit is to supply power for a number of 13 amp socket outlets and fixed appliances. However, whereas a ring final circuit terminates back at the consumer unit, a radial circuit terminates at the last outlet. Furthermore, the maximum floor area that may be covered by a radial circuit is much less than that for a ring final circuit. A radial circuit of 20 amp current rating may supply an unlimited number of outlets and appliances within an area of 20 square metres, and one of 30 amp rating may supply an unlimited number within an area of 50 square metres.

Generally, radial circuits are best used to supplement ring final circuits, particularly in a kitchen with a large range of electrical appliances. However, an appliance with a load in excess of 3,000 watts (3kW) should be wired on its own individual circuit protected at the consumer unit by a 30 or 45 amp fuse or M.C.B. In fact, all power circuits installed before 1947 were wired to just one socket outlet or fixed appliance apiece. The outlets were designed to take round-pin plugs of 2, 5 or 15 amps—the then standard current ratings— and the plugs did not contain their own fuses. If you have round-pin outlets and the circuits run from a number of separate fuse boxes, each with its own mains switch, then you can be fairly certain that the wiring is more than 55 years old. In that case, you should have the wiring checked as soon as possible, since it will certainly have deteriorated and may even be dangerous. Indeed, the electricity boards have declared that “any house over 25 years old may have dangerous wiring”.

• JOINT-BOX WIRING. In many houses built before 1966, the lighting circuit runs from a 5 amp fuse in the consumer unit to a series of joint boxes fixed between ceiling ioists. From each box run two more ;ables—one to the corresponding switch, the other to the ceiling rose.

• LOOP-IN WIRING. A modern lighting installation is most likely to use the loop-in system—so called because the supply cable runs direct from one ceiling rose to another Until all the roses are linked, or looped in, together. One cable is run from each ceiling rose to its corresponding switch.

A more Modern wiring. In a house with ring final circuit wiring, all the circuits run from a consumer unit with a single mains switch. Socket outlets are designed to take square-pin plugs of 13 amps and are connected by a continuous ring of cable. In most cases, one ring serves the upstairs socket outlets, and a second supplies those on the ground floor. In the same way, each floor is usually served by its own lighting circuit running direct from one ceiling rose to another. A cable goes from each ceiling rose to its corresponding light switch.

Very old wiring

In a house with pre-1947 radial wiring, the circuits run from a number of separate fuse boxes, each with its own mains switch. All the power circuits are connected to one socket outlet or one fixed appliance apiece, and the socket outlets are designed to take round-pin plugs of 2, 5 or 15 amps. The lighting circuits— usually one for each floor—run to joint boxes fixed between the ceiling joists. From each joint box one cable goes to the corresponding light switch and another goes to the ceiling rose.

Basic Tool Kit for Home Wiring

Tools for the electrical repair and improvement jobs require only a modest investment. Some of them may already be in your home tool kit -for example, such general-purpose devices as an electric drill, screwdrivers, saws, a hammer and a chisel. Others are more specialized and may need to be added.

electrician repairing a switch light

• TORCH. Always keep a torch by the fuse board or consumer unit. Then, if a fuse on a light circuit blows during the night, you will not have to grope about in the dark to repair or replace it.

• PLIERS. Two kinds are needed for electrical work. Long-nose pliers have elongated jaws that are ideal for bending a loop in the end of light-gauge wire so that it can be attached to a terminal. The jaws should be serrated to provide a firm grip and there should be cutting edges near the pivot so that you can snip the wire. Electrician’s pliers are used for bending and shaping heavy-gauge wiring and for twisting out removable parts from certain electrical components. These pliers should also have cutting edges and serrated jaws.

• DIAGONAL CUTTERS. Although electrician’s pliers can be used to cut cable, a pair of diagonal cutters will make the job much easier.

• WIRE STRIPPERS. As the name suggests wire strippers remove the insulation from electrical wiring. In the type shown below, there is a notched cutting edge at the end of each arm and a screw for adjusting the arms to the thickness of the wire. The cutting edges sever the insulation enclosing the wire but stop short of the wire itself, allowing the insulation to be pulled away.

• KNIFE. A sharp knife is needed to slit and then trim back the tough PVC sheathing round cable. A utility knife with a retractable blade is suitable.

• TERMINAL SCREWDRIVER. You need a variety of screwdrivers for wiring jobs, but the one you will use most frequently is the terminal type with parallel-sided tip. Although each of the tools shown below is properly insulated, views differ about the value of insulation. On the one hand, it is regarded as unnecessary since work should never be carried out on live circuits. On the other hand, insulation is regarded as a wise safety precaution in the event of mistakes.

Installing electric showers

A short video explaining the electrical requirements for an electric shower, in particular what to check before buying to ensure your intended purchase is compatible with your mains electric supply.

Instantaneous Electric Showers are still one of the most popular types of shower sold in the UK today. Which is why Triton manufactures an extensive range to suit all tastes and budgets.

An electric shower simply connects to a cold water supply and your mains electric, so it’s versatile enough to suit any home no matter what your plumbing system.

They are easy to install and they give you and your family instant hot water – any time, day or night.

So, what are the electrical requirements you need to know before you can choose an electric shower?

First of, all electric showers need to connect to your mains electric supply.

More to the point, it must have its own dedicated supply from your consumer unit.

It must not be connected to a ring main, spur, socket outlet, lighting circuit or cooker circuit.

The important thing is to ensure that the electric supply is adequate for the shower and existing circuits.

Check that your consumer unit has a main switch rating of 80A or above and that it has a spare fuse way to take the fuse or Miniature Circuit Breaker (MCB) for the shower.

The correct rating of MCB or fuse will depend on the kilowatt rating of the shower that is to be fitted. For more information on kW ratings take a look at our “What is a kW rating?” video.

If your consumer unit has a rating below 80A, or if there is no spare fuse way, then the installation will not be straightforward.

It may require a new consumer unit serving the house or just the shower.

For your protection, a 30mA residual current device must be installed. This may be part of the consumer unit or a separate unit.

The size of electric cable you need from the consumer unit to the shower depends on a number of things, such as – the kilowatt rating of the shower and the method of installing the cable…

…i.e. is it, or will it, be surrounded by loft or wall insulation. As a result, the cable could be anything from 6mm, to 10mm, or even 16mm.

To obtain full advantage of the shower, use the shortest cable route possible from the consumer unit to the shower.

In any event, it is essential that individual site conditions are assessed by a competent electrician in order to determine the correct cable size and permissible circuit length.

Finally before your electrics can go into the shower unit, you need to install a 45 amp double-pole isolating switch into the circuit.

This can either be installed inside or outside of the bathroom, but it must be readily accessible to switch off after using the shower.

Once you’ve fitted the switch into the circuit, all you have to do is complete the cable to the shower.

Depending on the model of shower, the cable will enter through either the top, bottom, sides or back of the unit.

Simply connect into the terminal block making sure the connections are good and tight so there is no risk of the cable overheating.

The final thing to say is that all electric showers must be installed in accordance with all the relevant water supply, electrical and building regulations.

Electric Showers: Plumbing Requirements.

A short video explaining the plumbing requirements for an electric shower, in particular what to check before buying to ensure your intended purchase is compatible with your cold mains water supply. The video also offers suggestions should your cold mains water supply not be adequate.

Instantaneous Electric Showers are still one of the most popular types of shower sold in the UK today. Which is why Triton manufactures an extensive range to suit all tastes and budgets.

An electric shower simply connects to a cold water supply and your mains electric, so it’s versatile enough to suit any home no matter what your plumbing system.

They are easy to install and they give you and your family instant hot water – any time, day or night.

So, what are the plumbing requirements you need to know before you can choose an electric shower?

First of all, you need to check that your mains water pressure and the flow to the shower meets the minimum required.

Water pressure is measured in units known as “bars”. 1 bar is approximately equal to a column of water 10m high.

The water pressure required for an electric shower varies from one electric shower to another depending on the manufacturer. Some require half a bar, while others require one bar or above.

The minimum flow rate required to operate the shower efficiently also varies from one unit to another and can be up to 10 litres per minute.

The kW rating of the shower also affects the water pressure and flow rates required. For more information on kW ratings take a look at our “What is a kW rating” video.

For guidance on water pressures and flow rates contact your local water company or consult a competent plumber.

If the water supply is adequate, you simply need to take a connection from a rising cold mains supply and run a pipe to your shower. Fit an isolating valve into the pipe before the shower for future servicing.

Depending on the model of shower, the pipe will enter through either the top, bottom, sides or back of the unit.

Simply connect the incoming water supply to the inlet of the shower making sure the connections are good and tight so there is no risk of leaking.

If the required water pressure and flow rate is not available from your mains water supply then it it’s unlikely that the shower will work.

However, this doesn’t stop you getting the shower you want.

You can always fit a separate pump in the water supply before the shower.

In this case, the shower cannot be connected to the cold mains supply, but to a cold water tank, instead.

Alternatively, you can choose an electric shower with a built-in pump such as Triton’s T90xr which also connects to your cold water tank.

For more information on this take a look at our “What is a pumped electric shower?” video.

The final thing to say is that all electric showers must be installed in accordance with all the relevant water supply, electrical and building regulations.