DIY repair advice as well as how to stay safe

Safety

Is it essential to have a good knowledge of electricity before work is carried out to an appliance?
This is a question often put to me by the diy enthusiasts or the would be service engineer. To them, the answer is yes, to the extent that electricity is dangerous and you should always unplug the appliance before you carry out any work to it. It is a matter of life and death that you unplug the appliance and do not just switch it off from a switch because switches can fail and are known to have failed.

Are there any other danger to working with electricity?
Well, we should also know that water and electricity are a lethal mix so it is vital that work is carried out in a dry area and that the appliance and its components are dry before connecting it to the power supply.

The only way you can be certain of your safety is to ensure the appliance is not connected in any way to the mains electricity supply.

Are there any other precautions I should be taking?
From an electrical point of view, once the appliance is disconnected, it is then completely safe to work on and will not cause you any harm. However, there are many sharp edges that can cause serious cuts so work with ring spanners and not open ended ones to avoid slip of the hand.

What about electrical damage to the appliance?
Electrical damage caused to an appliance is obviously down to how much care you take. Precaution should be taken to ensure wires that are disconnect are connected back the same way. It is a good idea to take a close up photograph of the connections before any disconnections of wires are made.

What are the risks of electrical damage to the appliance?
There are no risks if you observe certain rules and the rules are: Connect back the way they were before you disconnected. So you must note before you disconnect things.

What are the dangers if I connect wires up wrongly?
The things that you are more likely to connect the wrong way round are drain pumps, heater elements and water solenoids. You may think that by doing so, it will cause a big bang. Have no fear, that is not the case. The worst that can happen is that things will work in reverse. For example, the impeller of the drain pump will turn in the opposite direction. How so?

AC and DC power supplies
All the appliances in our database operate on AC power supply. AC is abbreviated for alternating current. Technically, that is what is happening to the live (L) and neutral (N) wires at 50hz per second. Therefore, physically alternating the wires will not cause a bang.

This principle is different to DC. DC is abbreviated for direct current. The wires that carry positive (+) and negative (-) current can not be interchanged. If this were to happen, there would be a bang.

Under what conditions would a short circuit (bang) occur when working on an appliance?
If you join the live (L) wire and the neutral (N) wire together, with the appliance connected to the mains and switched on or if you allow live or neutral to touch the earth wire or the body of the appliance. The earth wire is also connected to the body of an appliance for safety reasons.

A short circuit may cause the fuse of the appliance to blow or the RCD to trip. These are safety features put in place to prevent the possibility of a dangerous fault going un-noticed on the appliance.

summary
• Do not work on an appliance while it is connected to the electricity supply
• Ensure the appliance and the area you are in is dry before connecting to the electricity supply
• It is safe to work on an appliance if it is disconnected from the electricity supply
• UK appliances use AC mains power supply
• Heaters, drain pumps and water solenoids requires approx. 240V AC to function
• Alternating the live (L) and neutral (N) wires of heaters, drain pumps and solenoids will not casus a short circuit.
• Short circuits are caused by live (L) and neutral (N) wires touching or when these wires touch ground or the appliance body
• The connecting blocks on uk appliances makes it very difficult to wrongly connect wires

Remember, always inspect and take note before you remove. Take a close up photograph if possible as well