Guides on household electricity
Everything about electrics at home: we explain what's behind the meter cabinet, residual-current circuit breaker and E-Check – in the language we also use on site.
What we're asked most often
Three topics keep coming up in our phone calls: electrics in older buildings, the E-check and sudden power outages. We've also written down what we otherwise explain at the meter cabinet.
Old building electrics
Why wiring from the sixties reaches its limits, how to recognise two conductors instead of three, and what a phased renovation means.
Learn morePreparing for the E-Check
Which documents we'd like to see and which meter cabinets and distribution boards need to be accessible.
Learn morePower outage – first steps
In what order to check the fuse, residual current device and the neighbourhood before reaching for the phone.
Learn moreFrequently asked questions
Short answers on appointments, costs, test reports and the emergency call-out service – all gathered on one page.
Learn moreWhere the line to a specialist company lies
Changing a lightbulb isn't an electrical installation – opening a socket box is. On the phone, we'll tell you honestly whether a call-out is worthwhile at all, or whether you can sort it out yourself in two minutes.
What you can check yourself
- Replace bulbs and power strips
- Switch a tripped circuit breaker back on
- Unplug appliances and switch them on one by one to find the cause
- Ask your neighbour whether they're also without power
- Open the housing of sockets, switches or distribution boards
This is for us to handle
- Work in the meter cabinet and on the house connection
- New circuits, cable routes and sub-distribution boards
- Measuring loop impedance, insulation and trip times
- A residual current circuit breaker that trips repeatedly
- Any system with burn marks or a smell of melted plastic
Everything is decided behind the wall
What you see on switches and sockets is the smallest part of a system. Whether it holds up only becomes clear when you look at cable cross-section, protective earth conductor and distribution boards – and that's exactly what our guide articles are about.
Read about electrics in older buildingsProcess
The E-check step by step
The E-Check is the recurring inspection of your electrical installation and the connected devices. It follows a fixed sequence of visual inspection, measurement and functional testing. So you know what to expect, here we describe what we actually do during an appointment in a residential building.
We open the meter cabinet and distribution board and check whether cables, terminals and covers are undamaged. This reveals what can be seen without a measuring device: loose terminal points, heat marks on fuses, missing covers, parts added later without labelling, or old fabric-sheathed cables. Sockets, switches and light fittings in the rooms are also inspected.
We then measure using an installation tester. This checks the continuity of the protective conductor, the insulation resistance of the cables, the loop impedance as a measure of whether a fuse will trip quickly enough in the event of a fault, and the tripping current of the residual current device, or RCD. Every measured value is recorded so that a comparison is possible at the next appointment.
We trigger each RCD using the test button and via a current measurement, and record the tripping time. Switches, buttons, motion detectors and lighting circuits are tested for continuity. For equipment testing in commercial and administrative settings, we supplement the test of portable devices with protective conductor and leakage current measurement.
At the end, you receive a test report with all measured values and the condition of the system. If there are any defects, we classify them: what needs to be fixed immediately, what can wait, and what is simply an indication of the system's age. On this basis, you decide on further work – without pressure and with a prior cost estimate.
How you can help us save time
From practice
Common cases from everyday life
A large part of our calls revolve around the same observations. Here's what might be behind them and how we usually proceed – so you can provide the right information on the phone.
The RCD keeps tripping
Usually a single device is the cause: a damp outdoor socket, a defective heating element in a washing machine or dryer, an old power supply. We disconnect the circuits one by one and measure the leakage current until the culprit is identified. If several circuits share a common breaker, small leakage currents add up – in that case, splitting them across multiple RCDs in the distribution board helps.
Sockets without earth contact
In houses from the sixties and seventies, the third conductor is often missing. Simply replacing the socket isn't enough, because the earthing function is absent. We check whether rewiring from the distribution board is possible and plan it in sections – usually starting with the bathroom, kitchen and work areas.
Meter cabinet too small
A wallbox, heat pump or solar system needs space in the distribution board and a suitable meter slot. We check how many module spaces are free, inspect the main connection and clarify registration with the grid operator. Often the result is a new meter cabinet panel instead of lots of individual workarounds.
Flickering lights, warm fuse
Both point to contact resistance at terminal points. Old screw terminals loosen over the years, especially with aluminium conductors. We retighten the terminals in the distribution board, measure the heating under load and replace damaged terminals. Please don't put this off: heat at a terminal point is a fire hazard.
Still have questions about electrics in your home?
Ask us your question, and we'll get back to you with a clear answer.