Hints and tips
If in doubt, always seek advice from someone suitably qualified
If in doubt, always seek advice from someone suitably qualified
If you have a ‘earth trip’ that keeps ‘tripping’
If your fuse box is fitted with a RCCB (Residual Current Circuit Breaker) or RCD (Residual Current Device) then by turning off all the circuits, resetting the RCD and turning on each circuit in turn, you can narrow the problem to a smaller part of the installation.
When you have found the one circuit that is causing the problem, you have the choice of either calling in an electrician to sort it out, or dividing the circuits further.
If it’s on the lighting, try turning all the lights off and then back on, one at a time. If it’s on the power, try unplugging everything (including turning off the central heating and immersion heater!). If you still have no luck, then it really is the time to call in the experts!
The secret is in understanding how the RCD works.
It works on the principle that the current going to a circuit should be equal to that coming back. Real life means that every appliance/circuit has a small ‘leakage’ and the device measures this. If it is greater that the trip value, then it thinks something is wrong and switches off the current.
The wiring regulations require that any socket that can supply an appliance outside the equipotential zone (outside or in a garage - for example), or has wiring less than 50mm from finished level and not protected by earth metal, must be protected by a 30mA RCD. This includes sockets near a garden that may be used for mowing the lawn for example.
It is generally accepted that an installation protected by a 30mA RCD is unlikely to produce a danger to humans. However, a 10mA trip will ensure full protection even though no death has been recorded by electrocution by an installation protected by a 100mA RCD.
Just a little addition, those ‘surge protected’ extension leads cause problems if you have an installation protected by a 30mA RCD.
When you have found the one circuit that is causing the problem, you have the choice of either calling in an electrician to sort it out, or dividing the circuits further.
If it’s on the lighting, try turning all the lights off and then back on, one at a time. If it’s on the power, try unplugging everything (including turning off the central heating and immersion heater!). If you still have no luck, then it really is the time to call in the experts!
The secret is in understanding how the RCD works.
It works on the principle that the current going to a circuit should be equal to that coming back. Real life means that every appliance/circuit has a small ‘leakage’ and the device measures this. If it is greater that the trip value, then it thinks something is wrong and switches off the current.
The wiring regulations require that any socket that can supply an appliance outside the equipotential zone (outside or in a garage -
Just a little addition, those ‘surge protected’ extension leads cause problems if you have an installation protected by a 30mA RCD.
If in doubt, always seek advice from someone suitably qualified
Fitting a replacement light fitting.
You go out an buy a nice new light fitting and the instructions say ‘connect the brown wire to the brown (red old) wire on the fixed wiring, connect the blue wire to the blue (black old) wire on the fixed wiring and the green/yellow to the green/yellow on the fixed wiring.
Easy, you say, and unscrew the old fitting, disconnect the wires and are then presented by 3 red, 3 black and maybe nothing else! So much for instructions!
Once again, the secret is understanding real world basic principles. Your house wiring ‘loops’ the live/neutral/earth wires from the fuse box to each light in turn until you get to the last one (which should be no more than the tenth!). This will give you 2 live/2 neutral and hopefully 2 earth wires to each light. Unfortunately, they frequently need a switch and electricians being electricians, often use the same cable for this as well, so you end up with another brown/blue (red/black) and earth wire, only this time, the blue (black) is live when the switch is on.
If you are still set on ‘doing it yourself’ and if the new fitting needs an earth (they are the green/yellow ones!), but your wiring hasn’t, then you do need to get advice. If you need an earth and your wiring has the earth wires not connected to anything or just twisted together, then again, get advice.
Switch off the electricity before you start and make sure it is off by ensuring the light doesn’t work (before touching anything). The wire you have to ‘identify’ is the blue (black) switch wire. This is ‘of course’, the live switch wire. If, you’ve ‘lost’ it, then call for help or use some form of tester to positively identify it.
If the fitting requires an earth and the provisos above do not apply, connect to the earth terminal marked ‘E’.
Use a connector to terminate all the brown (red) wires if the new fitting doesn’t allow a terminal for this purpose. The next is to connect all the blue (black) wires, except our blue (black) live, to the fitting terminal marked neutral, or where the instructions say or maybe connect to the fitting blue wire. The odd blue (black) wire (switched live) is connected to the terminal marked ‘live’, or where the instructions say or maybe the brown (red) wire.
Securely fit the light fitting, ensuring no wiring is trapped, and the job should be done.
If in doubt, always seek advice from someone suitably qualified