Cumhuriyet, Kartal

In the dense family apartment blocks of Kartal's Cumhuriyet Mahallesi, kitchen renovations leave a built-in oven, microwave and dishwasher all fed from a single old 2.5 mm² branch. When the three run together at dinner time, crackling comes from the socket back-box behind the counter and a sharp plastic odour spreads; that odour is a definite sign the outlet has begun to melt and the socket must be taken out of service immediately.

The repair cuts blackened conductor ends back to clean copper, replaces the back-box and pulls an unbroken TSE-certified 3x2.5 mm² solid copper cable from the board to the counter behind the skirting, using the existing trunking route without chipping the wall. A separate C16 for the oven and another for the dishwasher permanently end the practice of loading three appliances onto one leg. The board is upgraded to a modular DIN-rail enclosure with lighting, sockets and wet rooms on separate devices.

The most frequent call in Cumhuriyet is a residual current device that trips again the instant it is reset. The technician disconnects every branch at the board and resets the device; if it holds the fault is in the installation, if not the device itself has failed. Branches are energised one at a time until the offending leg is certain, and that leg is measured with a 500 V megohmmeter. This separates leakage from a damp bathroom junction box, a charred kitchen terminal or a defective appliance.

Inverter air conditioners, induction hobs and LED drivers generate high frequency harmonics that trip a standard Type AC device for no apparent reason; in those flats it is replaced with a Type A or a harmonic-immune Type F unit. At Cumhuriyet addresses a single 30 mA device commonly protects the whole flat, so lighting, sockets and wet rooms are split onto separate devices. After installation the trip time is measured in milliseconds with a dedicated tester and written onto the service report.

If breakers trip in Cumhuriyet when the air conditioners start on a summer evening, the first job is measuring inrush with a clamp meter. In most flats the units hang off a socket circuit and peak at thirty-five to forty amperes on start-up; the existing C16 breaker sees that surge thermally and opens. Enlarging the breaker is not the answer, because it leaves the 2.5 mm² cable unprotected and raises the fire risk.

The correct installation runs a dedicated circuit from the board to the outdoor unit: 3x2.5 or 3x4 mm² according to power, a C20 or C25 motor characteristic breaker and its own residual current device. In multi-split flats like those in Cumhuriyet, all three phase currents and the neutral are read separately and loads redistributed across the busbar, because air conditioning clustered on one phase heats the neutral terminal to around one hundred and sixty degrees. The interconnecting cable is specified screened and the condensate line is never routed below a socket.