Frequently Asked Questions
Here are a list of questions that get asked on a fairly consistent basis from job to job, as well as some helpful hints on performing some basic electrical tasks. If you would like further questions answered, please submit your inquiry via the contact form.
Are You Insured?
Great question! (possibly the most important). Lavender Electrical is insured with Direct Line to a Public liability of £2,000,000 and Employers Liability of £5,000,000. Public liability insurance covers the cost of compensation for: personal injuries and loss of or damage to property. We will happily produce the certificates on request.
How Dangerous Is Electricity Anyway?
Electrical safety is no joke. Electricity will always try to take the easiest path of least resistance back into the Earth, through whatever is in its way, including a human being. With the use of earth wires, any fault created will travel preferentially down the earth wire and cause the fuse to break the circuit, instead of travelling through you. The best defence for electrical safety is an up-to-date fuse-board equipped with RCD circuit breakers. An RCD constantly monitors the electrical current flowing through a circuit and will switch off the supply very quickly if it detects any problems. If you receive an electric shock, as little as 50 mA alternating current can result in heart fibrillation, which is generally fatal unless treated within minutes. And it doesn't have to be from high voltage sources - depending on the resistance of your body (which can vary greatly) will result in more or less current (volts = current x resistance)
My Circuit Breakers Keep Tripping - Why?
I have been called out a few times for a term called nuisance tripping, which is really just the RCD doing the job that it was intended for (always good to know). Travelling in the direction of incoming electricity, most modern day fuse boards are configured with a main (red) switch first, which switches off the whole board. Behind this there follows a main RCD switch, followed by a row of up to 6 MCBs (miniature circuit breakers), then another RCD main switch followed by another row of up to 6 MCBs. An RCD will trip (switch or activate) when it detects a leakage of electricity (current) from either the live or the neutral conductors to earth. The nuisance part of the tripping is when the RCD trips frequently and for no apparent reason.
What is actually happening is the RCD is reading the leakage to earth across all of the MCBs after it. The sum of these leakages adds up to more than the leakage limit that the RCD can handle. So far I’ve been lucky and have been able to swap the circuit with the most leakage across to the other RCD on the board and it’s been okay.
However, it could mean a couple of things:
Firstly, when the RCD trips you should switch all the MCBs after the RCD off and then try and switch the RCD back on. If you can, then switch each MCB back on one at a time. Should the RCD trip when you switch one MCB on, leave this one off and switch all the others back on. Generally, you will find it is the sockets which are the culprit, so unplug everything on this circuit and try and switch the MCB back on. If that works, plug everything back in one device at a time until it trips again and you will find which appliance is tripping the RCD. If the circuit does not go back on, then you need to call on an electrician to find the problem for you. Please contact Lavender Electrical for assistance.
What is actually happening is the RCD is reading the leakage to earth across all of the MCBs after it. The sum of these leakages adds up to more than the leakage limit that the RCD can handle. So far I’ve been lucky and have been able to swap the circuit with the most leakage across to the other RCD on the board and it’s been okay.
However, it could mean a couple of things:
- having to change all the MCB’s to RCBO’s (a special type of circuit breaker, or Residual Current Breaker with Overcurrent), which are effectively a separate RCD for each circuit, or worse,
- that there is a problem with the wiring and complete rewiring will be necessary.
Firstly, when the RCD trips you should switch all the MCBs after the RCD off and then try and switch the RCD back on. If you can, then switch each MCB back on one at a time. Should the RCD trip when you switch one MCB on, leave this one off and switch all the others back on. Generally, you will find it is the sockets which are the culprit, so unplug everything on this circuit and try and switch the MCB back on. If that works, plug everything back in one device at a time until it trips again and you will find which appliance is tripping the RCD. If the circuit does not go back on, then you need to call on an electrician to find the problem for you. Please contact Lavender Electrical for assistance.
Can I Do My Own Electrical Work?
As a homeowner you are entitled to carry out any electrical works in your home. Some smaller jobs like installing light switches and light fittings, wall lights etc may not be required to be notified for Part P compliance. See Planning and Design for more info. Should you need to certify the work in accordance with BS 7671 wiring regulations and register it with Part P building control for compliance, you will be required to provide evidence that you are a 'competent person' and have carried the work out correctly. You will need to provide certification. If in doubt, please contact Lavender Electrical and we will be happy to give you advice and assist you if necessary.
What Precautions Should I Take When Working With Electricity
There are same basic precautions you can take when working with electricity which could save your life and the life of others around you.
- Know where the panel and circuit breakers are located in case of an emergency, ensure ease of access, and label all circuit breakers and fuse boxes to identify which outlet or appliance it is for.
- Turn off the power when working with electricity.
- Occasionally inspect electrical cables and fittings for damage and repair or replace damaged equipment immediately. Note that excessive heat at an outlet can be an indicator of an electrical fault, and should be investigated.
- Use extension cords rated for the level of current or power that you are using.
- Always use the correct size fuse. Fuses are there to limit the amount of current flowing through the circuit. Excess current due to unnecessarily large fuses can cause cables to overheat and could potentially start a fire. Damage could also occur to equipment (or you).
- In wet areas and rooms, install RCDs which limit the current level and time that a person is exposed to electricity.
- Do not approach a person or appliance if there is a suspicion that they are electrically "live". In the case of injury from shock, disconnect the power and call 999.
