Evliya Çelebi, Tuzla

Evliya Çelebi is a Tuzla neighbourhood dense with mass housing blocks, and here the installation begins not inside the flat but at the distribution board at the block entrance. These boards can feed up to forty flats in a single block, and as load has grown the busbar terminals heat and carbonise in the evening. Voltage swings experienced in one flat are usually the result not of that flat but of a loose neutral connection in the block board.

For diagnosis the block board is opened, load currents read phase by phase with a True-RMS clamp meter and the voltage between neutral and earth measured; anything above a few volts points to a loose or oxidised neutral. Carbonised terminals are renewed with fire-rated ceramic blocks, connections torqued to 3 Nm and busbar faces cleaned back with dielectric solvent. The board is swept under load with a FLIR thermal imager to find latent hotspots, and a measurement report is left with the building management.

In the older stock of Evliya Çelebi a ceramic screw-in fuse board still sits in the hall cupboard. These boards contain no residual current device at all, so protection against electric shock is zero; the fuse melts and welds into its base under overload, fails to clear a short circuit and the body carbonises over time. The sockets usually have no earth either, with the neutral pin bridged to the earth terminal.

The old board is removed entirely and a flame-retardant modular DIN-rail enclosure installed: an independent Type C breaker per room, dedicated circuits for kitchen and bathroom, and a 30 mA Type A residual current device plus a Type 2 surge arrester at the intake. Flat sub-boards use a minimum 6kA breaking capacity and building intakes 10kA. Where a Evliya Çelebi address has no earth, a solid copper electrode is driven, its resistance measured with a digital earth tester and the socket jumpers removed one by one.

In Evliya Çelebi, seven to nine kilowatt instant water heaters retrofitted into bathrooms are connected to existing thin 1.5 or 2.5 mm² circuits. During a shower the run overheats, the terminal in the ceiling junction box melts and the residual current device trips. In unventilated internal bathrooms shower steam leaves condensation in the box over the years; the terminal takes on damp, leakage current climbs and the device starts tripping after every shower.

The correct installation is an unbroken 3x4 mm² fire-retardant cable from the board, a C32 breaker and its own 30 mA Type A residual current device, with trip time verified by tester. The heater's chassis earth is always measured and the unit is not energised without a protective earth, because potential on the chassis is lethal on a wet floor. The junction box is dried and encapsulated in dielectric silicone gel, and an IP44 moisture-proof luminaire plus a run-on timer extract fan dry out the root cause of the condensation.