Electrical

Electrical

How to Isolate the Electricity Supply

  • To truly be safe the best way to isolate the electric supply is to turn off the main switch which is the first switch after the meter.  This is normally the big RED switch on the fuse board, it should say main switch on it, but it could be a switch on the wires between the fuse board and the meter. MAKE SURE IT CAN’T BE SWITCH BACK ON WHILE YOU’RE WORKING ON IT.
  • To look safely behind a socket front when you need to keep the lights on, you could isolate the individual socket circuit by plugging in a lamp and one at a time turn of all circuit breakers or pull fuses labelled sockets. If the breakers/ fuses are not labelled, then the sockets will either be on a 30/32A circuit (red dots) or a 20/16/15A circuit (yellow/ blue dots). To make sure the light has not broken, after you have tested turn the circuit back on to make sure lamp turns back on, then isolate again when satisfied correct one is found. MAKE SURE IT CAN’T BE SWITCH BACK ON WHILE YOUR WORKING ON IT.
  • To look safely behind a light switch when you want to keep sockets on. Turn on the light switch which you want to look behind and then turn of the breaker or pull the fuse on all circuits marked lights one at a time until the right one is found. If the breakers/ fuses are not marked they will be a 5/6/10A (white dots). Turn lights back on again to make sure lamp hasn’t broke then turn off again if satisfied correct one is found. MAKE SURE IT CAN’T BE SWITCH BACK ON WHILE YOU ARE WORKING ON IT.

What is an RCD?

  • An RCD is the switch with a test button on it. RCD’s work differently to fuses as they measure the balance of electric passing through it and not the amount. What goes up the live i.e. 10.23A must come down the neutral 10.23A so if it detects any difference over 0.03A it will break the circuit.
  • An RCD powers the circuit breakers next to it and should have a sticker on the board indicating which ways/ CB’s (circuit breakers) it controls.
  • A RCBO works the same way as an RCD but it looks like a Circuit Breaker and only operates the individual circuit. Again you can tell the difference by the test button on it.

What are Main Cable Tails?

  • Main tails are the live and neutral cables which run from the meter to the fuse box.
  • In Britain there is a standard size of 25mm² for newly installed live and neutral main supply cables.
  • If new cables are to be installed or a new fuse box is being installed 25mm is the size which should be fitted.
  • If the supply cables are not the correct size although it is recommended to have 25mm² tails, if 16mm² (the next size down) exists then it is not “illegal” to keep the existing cables.
  • 16mm² existing tails can safely manage the load up to 80A. The maximum load to carry will depend on the main fuse which is before the meter.
  • If 16mm cables are protected by a 100A fuse it is recommended to get the tails upgraded.

What is the Main Bonding?

  • Main earth cable is the earth cable which supplies the earth to the fuse box which then earths each individual circuit.
  • Main earth bonding is the earth cable which connects the fuse box to the water stop tap and the gas meter (oil supply in some rural areas).
  • To check if the earth bonding cable is 10mm, put a fuse found in a standard plug socket (BS1361) next to it and it should be the same size, if the cable is larger that’s ok too.
  • The main earth cable should be 16mm², so older houses might need an upgrade. It is a safety recommendation and is not “illegal” if not done.
  • The main earth bonding should be 10mm², so older houses might need an upgrade. It is a safety recommendation and is not.
  • The earth bonding cable is there because if a live cable touches the pipe, it will blow the circuit which is at fault. If the pipe is not earthed, then the pipe could potentially become like a big, exposed cable with no insulation to protect people from an electric shock.

Do I Need a rewire?

  • Most rewires are done because of the age of an installation but it may not be necessary.
  • If a large amount of work is to be done in the house and it has old wiring and more sockets are to be fitted, then it might be the best time to get a rewire done.
  • If fuses/ breakers trip a good electrician will be able to test and inspect and give a diagnosis to what is needed. Often a small fault can be found and is easily corrected.
  • Most houses which may be ready for a rewire often have lights close to the window and have only 1 socket per bedroom near the door.
  • Modern living often requires more sockets and can be added if an inspection and test shows good readings. Poor readings may mean a rewire will be best.
  • A partial rewire can be done if there is a problem with only one circuit, but it is a messy job, and if one circuit needs a rewire it would be recommended to get the other circuits done if they are the same age.

What are Timers and Photocells?

  • Timers can be used to turn the power on and off to the light or heater etc. which are either 24hr or 7 days.
  • Photocells react to light so when it gets dark your light will come on and turn off when it gets light.
  • Timers and photocells can be put together so the photocell will turn the light on only when it gets dark and turn off using the timer.
  • Sensors switch the lights on when it picks up movement and off after a set period when the motion has stopped, they normally also have a photocell built in so it’s not operating in the daytime. The downside is it will pick up people or cats or other animals passing the sensor.
  • Light fitting can be bought with timers, photocells and sensors built in.

What Smoke Detector should I Use?

  • You should have at least one smoke detector on each level of the house.
  • You should also have a smoke detector on the hallway ceiling outside of sleeping areas (bedrooms). Remember to install a separate smoke detector in each sleeping area if you have multiple sleeping areas located in different areas or different levels of the house.
  • Kitchens are important when choosing locations for smoke detectors. Put one either inside using a heat detector or just outside the kitchen. Smoke from cooking causes nuisance alarms.
  • Ionization smoke detection is generally more responsive to flaming fires. They basically smell a fire.
  • Photoelectric smoke detection is generally more responsive to fires that begin with a long period of smouldering. They basically see the fire.
  • Heat detectors are used in kitchens as they will not sound an alarm when cooking.
  • Smoke detectors can be battery operated but you must change the battery every year. Mains voltage detectors are the best as the battery is just for back up. If you have more than one detector they should be interlinked (which means they tell each other if there is a fire).
  • Radio bases can be used to link the smoke detectors which means they will all sound their alarm when just one picks up smoke in the house. Normally a cable will have to be fitted between the detectors, which means chopping the cable in to plaster or clipping the cable to the wall or fitting trunking, but with a radio base a cable will have to supply the detector, but it can be taken from a close supply.
  • Land Lords should ensure smoke alarms are repaired or replaced once informed and found that they are faulty.The requirements are enforced by local authorities who can impose a fine of up to £5,000 where a landlord fails to comply with a remedial notice

Do I Need a Carbon Monoxide Detector?

Carbon Monoxide Detectors were only required where solid fuel burning was in a living space (Reg 2015), But in 2022 the regulation requires a Carbon Monoxide Detector in any room as living accommodation which contains a fixed combustion appliance (excluding gas cookers). Land Lords should ensure carbon monoxide alarms are repaired or replaced once informed and found that they are faulty. The requirements are enforced by local authorities who can impose a fine of up to £5,000 where a landlord fails to comply with a remedial notice.

What Fan Should I have?

  • Fans can be mounted on the wall or on a ceiling if there is a loft above.
  • If a fan is to be mounted on a ceiling it must have to be able to exit the loft through ducting either through the eves or through a gable end wall, or out through a vent tile in the roof.
  • If the fan is to be fitted to a wall it will need core drilling which is a hole the size of the fan duct to vent outside. Core drilling creates a lot of dust.
  • Fans can be switched either with a pull cord fitted in the fan or by a pull cord or switch put in a convenient place.
  • Fan switches are normally located next to light switches, or the fan can be switched on with the lights.
  • Fans which come on with the lights can have an override on them which makes the fan continue running for a timed period after the light has been turned off.
  • Fans can have a humidistat fitted which turns the fan on when there is moisture in the air.

What is a Pressurised Fan?

  • Pressurised fans are used to push air into a house which then forces damp out of the house.
  • Pressurised fans come in a few different designs.
  • The most common being the fan which sits in the loft and blows air into the landing area.
  • If just the bathroom is a problem a normal fan could be exchanged for a pressurised wall fan.
  • There is a design of pressurised fan which can be used if there is no loft i.e., in a flat.

What Fan Controls Damp/ Mould?

  • Pressurised fans are used to push air into a house (Common fans suck air out) which then forces damp out of the house.
  • Pressurised fans come in a few different designs.
  • The most common being the fan which sits in the loft and blows air into the landing area.
  • If just the bathroom is a problem a normal fan could be exchanged for a pressurised wall fan.
  • There is a design of pressurised fan which can be used if there is no loft i.e., in a flat.

What is an Electrical fuse Spur?

  • A spur is the general term used for a circuit which comes off the socket circuit.
  • A fused spur is the size of a single socket.
  • A fused spur can be with or without switches.
  • Anything could be put on a fused spur which will not move which normally would have a plug on it. Pumps, boilers, fires, fans are the most common thing to have on a fused spur.

What is a Pattress Box?

A pattress is a white box which the socket or switch sits in when the socket/ switch is not being sunk into a wall.

What are the Different Boilers?

Only combi boilers supply central heating and hot water direct with no hot water tank, all other boilers have a hot water tank.

A back boiler is an old style of boiler which is built into the gas fire.

A S plan system has a valve fitted to the hot water supply and a valve is also fitted to the central heating.

A Y plan system has just 1 valve controlling the hot water and the central heating.

How to find if the lights are Earthed.

  • The easiest way to check if the lighting circuit is earthed is to in the daytime turn on the light in a bright room.
  • Go to your fuse box and turn off all lighting circuits which is the fuse with the white dots or 5A/ 6A/10A circuit breaker, the light should now stay off if the light switch is up or down.
  • Unscrew the front plate to see behind and if the lighting circuit is earthed then you will see a yellow and green or just green covered wire connected to the back box or in a block.
  • Screw the front plate back on and be careful not to trap the wires between the screw and back box and turn the power back on at the fuse box.

How to find the Correct Circuit.

  • To find the correct lighting circuit turn on the light switch which you want to have work done on and then turn of the breaker or pull the fuse on all circuits marked lights one at a time until the right one is found. If the breakers/ fuses are not marked, they will be a 5/6/10A (white dots).
  • To isolate an individual socket circuit plug in a lamp and one at a time turn of all circuit breakers or pull fuses labelled sockets. If the breakers/ fuses are not labelled, then the sockets will either be on a 30/32A circuit (red dots) or a 20/16/15A circuit (yellow/ blue dots).

What is my Cable Size?

Cable is measured by the cross sectional area of the conductor (the copper bit). You might find the cross section area written on the grey sleeving or yellow and green sleeving if it’s an earth cable.  The Common  sizes in the UK are 1mm  for Lighting, 2.5mm for Sockets, 6mm for Cookers, and 10mm for showers. Obviously this can vary as 1.5mm cable can also be used on Lighting, 4mm can be used for Sockets, and 6mm can be used on low Wattage Showers. An easy way to find if a cable is 6mm or 10mm is check if the earth is a single core (6mm) or stranded multiple cores (10mm), but some older 6mm cables had multiple cores but is rare.

What Type of Thermostat Can/ do I Have?

Mechanical thermostats are basic on/ off thermostats which are the easiest to use.

Digital thermostats can turn the heat on and off with the temperature and also the time can be set to turn the heat on and off. They can be Complicated for old people to use.

Can a New Socket/ Circuit Come off the Existing Socket Circuit?

If the fuse box is close enough to the new circuit and there is a spare way in the fuse box then a new circuit is always the best option, but it might be possible to come off the socket circuit.

If you have a good 32A ring circuit (2 cables feeding the socket) then in most cases, it will be possible to just extend it off a socket close to the new Circuit/ Socket.

If you have a 20/16/15A radial circuit (1 cable feeding the socket) close to the New Circuit/ Socket and you are just having a light and TV type equipment in there then it might be possible to extend off that socket. If you are having electric heating or air conditioning in the area then a new circuit from the fuse board might be needed.

The installing electrician will need to do a Zs test first on either the radial circuit or ring circuit to determine if the fuse protecting the circuit will trip in time if there is a fault and calculate usage on the Original Circuit.

What is Conduit and Trunking?

  • Conduit and Trunking are used to take cables up or across a wall.
  • Conduit and Trunking is normally used if cables aren’t being chased into a wall and looks neater than clipping a cable to a wall.
  • Conduit is round and is normally found in black or white.
  • Standard trunking is square and has a lid for access and is normally found in white or brown. Decorative trucking can be purchased and can be a variety of colours and shapes but a lot more expensive.

What are the Mains?

Water mains or Water mains supply is the Water stop tap (most often found under a sink) or the gas meter.

A supply is the cold or/and hot water to the sink or bath, toilet, shower etc.

Gas Mains is your meter which is often found in a box on the outside of the house but can also be anywhere in the house if not.

Electric Mains is the Electric meter and incoming fused supply, commonly found on the outside of the house in a box on the wall but also can be anywhere in a house including a cellar if there is one.

CCTV Information.

Consider what kind of CCTV system you want; you then need to plan what goes where. Switch controller’s (and line powered camera monitor) have all the cables come back to them, so keep it central or as close as possible to the connecting cameras and monitors.

Consider what type of camera is required. There are many different types available. Day only cameras will not see anything at night-time unless good lighting is available around the area. Infra - Red (IR) cameras are required for night-time viewing. Moveable pre- programmed and controllable cameras are also available these can cover different areas with a single camera.

  • The line powered camera is simplest system and therefore the cheapest system to install. line powered cameras have all cameras connected directly to a monitor with a coaxial cable, with the power for the camera/s being provided from the monitor. This is generally a DIY system which is relatively old but still available from some manufacturers.
  • The mains powered CCTV installation is where the camera has a dual cable (shotgun cable) carrying power on one side of the cable and the picture in the other. Mains powered cameras are not used as often due to low voltage ac/dc cameras now becoming more popular which use a low voltage power supply connected to the mains supply. A system may contain a combination of both mains and low voltage cameras. Both A video switch and controller will be used when you want to record any camera selected. The picture can be held on the screen or set to sequence in turn through all the cameras. To cut down on cameras, moveable cameras can be used to cover a wider area, and systems may contain a combination of both fixed and movable cameras.
  • The most used, and most modern of CCTV systems is where the cameras are connected with a dual cable (shotgun cable) carrying low voltage power on one side of the cable and the picture in the other. The cameras are connected to a DVR (Digital Video Recorder) which records images on an internal hard drive and can be transferred onto a CD when evidence is required. The DVR is also the switch and controller so no need for additional equipment and it can also control moveable cameras. The DVR can also be connected to a WIFI network and viewed on most smart phones. It will then be connected to a CCTV monitor, PC Monitor, or a standard TV for viewing of the cameras.
  • WIFI Cameras need a good WIFI signal to stream the view to your phone or tablet or TV. for recording you will a subscription to a supplier.

Satellite Dish and LMB Information

  • Look at where your neighbour’s satellite dishes are mounted, and your satellite dish will have to face the same way.
  • If there are no neighbours to copy off Apps can be downloaded for alignment or Google satellite alignment.
  • Satellite dishes can be mounted on a tall pole if you don’t want the dish mounting on the same facing wall as your neighbour’s. 
  • The LMB is the bit which points at the dish and receives the signal.