Glossary
PIA (pequeño interruptor automático, miniature circuit breaker)
The pequeño interruptor automático is the miniature circuit breaker (MCB) that protects each circuit of a Spanish home separately, such as lighting, sockets, kitchen or washing machine, against overloads and short circuits.
What a PIA is and where it sits
PIA is the technical Spanish name for the small MCBs (magnetotérmicos) lined up in your fuse box (consumer unit; breaker panel in the US), after the main switch (IGA) and the RCDs. Each one serves a circuit and should carry a label saying which. If one trips, only that part of the home loses power.
How many PIAs a board has
As many as the home has circuits. ITC-BT-25 sets them out:
- Basic electrification: five circuits, C1 to C5 (lighting, general sockets, cooker and oven, washing machine with dishwasher and water heater, and bathroom plus kitchen worktop sockets).
- High electrification: extra circuits for air conditioning, heating, tumble dryer and other uses, plus C13 for EV charging.
Usual ratings
The rating depends on the cable it protects. The cooker and oven circuit (C3) uses 6 mm² cable with a 25 A PIA, and the washing machine, dishwasher and water heater circuit (C4) 4 mm² with 20 A. You will also see 10 A and 16 A PIAs on lighter circuits, almost always curve C.
Why one trips
It trips on overload when the circuit has too many appliances, typical in kitchens when oven, microwave and kettle run together. It trips on short circuit when a cable, socket or appliance is faulty. If it resets and drops again straight away, do not force it: unplug everything on that circuit and, if nothing changes, call an electrician to find the fault. See MCB keeps tripping in Seville, Spain.
Related services
Fuse board replacement
A consumer unit replacement in Seville, Spain is the upgrade that adds the most safety without building work: main switch, several RCDs, one breaker per circuit and surge protection. We replace your old fuse box, or a board with a single RCD, with a new fuse board (breaker panel) sized for your power and your circuits.
MCB keeps tripping
If your MCB keeps tripping when you switch on the oven, the air conditioning or the washing machine, that circuit is overloaded or has a fault. We check the line, spread the loads or replace the circuit breaker (magnetotérmico) so your kitchen or living room stops losing power.
Need an electrician in Seville, Spain?
Call us or send a WhatsApp message with a photo of the job. You get a fixed quote before any work starts.