Tripping RCD or "fuses"? What it means and what you can safely check

First: what actually tripped?

In the distribution board you have two types of "guardians" and it is worth distinguishing them, because they indicate different problems:

• Residual current device (RCD, "różnicówka") - a wider module with a TEST button. It reacts to current "escaping" outside the circuit, e.g. through damaged insulation, moisture or - most importantly - through the human body. This is a life-saving protection;
• Overcurrent circuit breaker ("eska", colloquially "fuses") - a narrow module with a type designation B10, B16. It reacts to overload (too many devices at once) or a short circuit.

What you can check yourself

A safe elimination method, without unscrewing anything:

• unplug all devices on the circuit that trips from the sockets;
• turn on the protection - if it holds, plug in the devices one by one until you find the culprit;
• typical suspects for RCD: washing machine and dishwasher (heating element), boiler, old household appliances, devices that have had contact with moisture, outdoor lighting after rain;
• typical suspects for "eska": kettle + oven + microwave on one circuit, electric heater on an extension cord, short circuit in a damaged device cable.

If one device turned out to be guilty - take it to a service center or replace it. The installation did exactly what it was supposed to.

When it is the installation and not the equipment

• RCD trips without any device connected;
• it trips after rain or on humid days - a classic symptom of a damp junction box or damaged insulation (more in the guide on moisture in the installation);
• it trips randomly, also at night when nothing is working;
• the problem affects several circuits at once or appeared after renovation (drilled cable).

In such situations, guessing will do nothing - you need to measure the insulation resistance of the circuits and the parameters of the RCD itself. This is what our diagnosis looks like: measurements instead of guessing, result in writing, price of the diagnosis known before the visit.

What not to do under any circumstances

• do not replace a protective device with a larger one (e.g. B16 with B25) - the cables in the wall were selected for the smaller one; a larger device does not "fix" the problem, it only allows the cables to overheat;
• do not bridge or turn off the RCD "because it gets in the way" - it is the only protective device in the consumer unit that reacts to electric shock to humans;
• do not ignore the problem because "overall, it is livable" - an insulation fault does not resolve itself.