Few things are as frustrating as the power cutting out in the middle of cooking supper, and then cutting out again five minutes after you reset it. If your DB board or earth leakage keeps tripping, the board is doing its job: it has detected a problem and switched off to protect you and your home. The trick is working out what that problem is.
This guide explains the most common reasons a DB board trips in South African homes, what you can safely check yourself, and when it is time to call a qualified electrician.
First, which switch is tripping?
Open your DB board (the distribution board, usually near the front door, garage or kitchen) and look at which switch has dropped. This one detail tells you a lot.
- The earth leakage (the wider switch, usually with a “Test” button): it has picked up current leaking to earth. This is often caused by moisture or a faulty appliance.
- A single circuit breaker: that circuit is overloaded or has a short circuit.
- The main switch: the whole house is drawing too much, or there is a serious fault. A main switch that keeps tripping should always be checked by an electrician.
Common reasons the earth leakage keeps tripping
1. A faulty appliance
This is the most common culprit. Kettles, toasters, washing machines, dishwashers, fridges and geysers can all develop a small leak to earth as they age. The element in a kettle or washing machine is a classic example.
2. Water or moisture
Rain getting into an outdoor plug point, garden light or pool pump connection is a very common cause, especially during the Highveld summer storms. If your earth leakage only trips when it rains, moisture is almost certainly the problem.
3. A geyser element or thermostat fault
A leaking or corroded geyser element can trip the earth leakage, often at night or early morning when the geyser switches on. If tripping lines up with your geyser timer, that is a strong clue.
4. Damaged or old wiring
Cables that have been chewed by rodents, damaged during building work, or that have simply perished with age can leak current to earth. This is not something to fix yourself.
5. Power surges after load shedding
When power comes back after load shedding, the sudden surge can trip the earth leakage, particularly if several appliances, pumps and the geyser all switch on at once. A one-off trip at that moment is usually not a concern. Repeated tripping is.
Why a circuit breaker keeps tripping
If it is one breaker rather than the earth leakage, the usual causes are:
- Overload: too many high-power appliances on one circuit, for example a heater, kettle and microwave all on the same plug circuit.
- Short circuit: a live wire touching neutral or earth, often from a damaged plug, loose connection or faulty light fitting. This usually trips instantly.
- A worn-out breaker: breakers do weaken over time and can start tripping below their rating.
How to find the problem safely (step by step)
You can often narrow the problem down yourself without opening anything up.
- Unplug everything on the affected area, or switch off all the circuit breakers in the DB board.
- Reset the earth leakage (or the tripped breaker).
- Switch the breakers back on one at a time. If the earth leakage trips when a particular breaker goes on, you have found the faulty circuit.
- On that circuit, plug appliances back in one by one. If it trips when a specific appliance is connected, that appliance is likely faulty.
- If it trips with nothing plugged in, the fault is in the fixed wiring, a light fitting, the geyser or an outdoor connection. That is a job for an electrician.
Safety note: Never hold a breaker or earth leakage up to stop it tripping, and never tape it in the on position. Do not remove the DB board cover or work inside the board. If you need to touch anything other than the switches, switch off at the main switch on the DB board first, and call a qualified electrician for anything inside the board.
Test your earth leakage regularly
Your earth leakage is one of the most important safety devices in your home, because it protects people from electric shock. Press the “Test” button every few months. It should trip immediately. If it does not trip when tested, it may not protect you when it matters, and it should be checked and replaced if needed.
When to call an electrician
Call a qualified electrician if:
- the earth leakage or main switch trips again straight after resetting;
- it trips with every appliance unplugged;
- you notice a burning smell, scorch marks, buzzing or heat at the DB board or a plug point;
- tripping happens every time it rains;
- the earth leakage does not trip when you press the Test button;
- your DB board is old, cracked or still has ceramic fuses.
An electrician will use proper testing equipment to find exactly where the leakage or fault is, which saves a lot of guesswork. You can read more about our electrical services in Pretoria, including fault finding and DB board repairs.
Tripping after installing an inverter or solar?
If the tripping started after a backup power or solar system was installed, the cause may be how the inverter, earthing and earth leakage protection were wired together. This needs to be checked by someone who works on these systems. See our solar power and backup installations page for more.
Frequently asked questions
Why does my earth leakage trip when it rains?
Water is getting into an outdoor plug point, light fitting, pool pump connection or a damaged cable. Unplug outdoor items, and if it still trips, have an electrician check your outdoor wiring and fittings.
Is it dangerous if my DB board keeps tripping?
The tripping itself is a safety feature, but the fault causing it can be dangerous. Repeated tripping means something is wrong, so do not ignore it or bypass the switch.
Can a faulty appliance trip the whole house?
Yes. A faulty appliance can trip the earth leakage, which often covers most or all of the house. Unplugging appliances one at a time is the easiest way to find it.
Why does my earth leakage trip at night?
Night-time tripping often points to the geyser switching on, a timer-controlled pool pump, or moisture and dew affecting outdoor lights and plug points.
How often should I test my earth leakage?
Press the Test button every few months. It should trip immediately. If it does not, have it checked by an electrician.
Can I replace a circuit breaker myself?
No. Working inside the DB board is dangerous and should only be done by a qualified electrician.
Need help with a tripping DB board?
If your DB board or earth leakage keeps tripping and you cannot find the cause, Electrician Worx can help. We work across Pretoria and Centurion, including Lynnwood, Moreleta Park and surrounding suburbs. Find an electrician near you, call us on 012 383 2011, or contact us online.
