Kartal

In the high-rise residences of Kordonboyu and Yalı the generator must pick up automatically when the grid drops. If the contactor coil in the changeover switch burns out or the phase protection relay latches, lifts stall between floors and the booster pump goes silent. Our technician measures the control voltage in the transfer panel, replaces the coil and auxiliary contact block, and resets the phase sequence and voltage thresholds.

A lift supply is never tied to the general lighting leg; a dedicated breaker fed by its own NYY cable is run from the board to the machine room. Earth continuity of the control panel is measured, loose terminals torqued to specification, and the generator test repeated under load with a signed record issued. Generator fuel level and battery voltage are checked too, because the most frequent cause of a no-start in the field is a flat cranking battery rather than a burnt coil. Shaft lighting and the in-car emergency intercom circuit are also tested, since their operation is vital the moment someone is trapped.

In the large family flats of Soğanlık and Yakacık a washing machine, tumble dryer and heater all feed from one outlet via a multi-way extension block. Once the current through the single 2.5 mm² run approaches thirty amperes the cable insulation chars, the socket back-box blackens and warmth is felt through the wall. The extension block body itself starts to melt and a fire risk develops.

The fix is removing the extension block and running a separate circuit from the board for each appliance. Continuous loads such as a dryer or heater get 3x4 mm² cable on a C20 breaker, while the washing machine circuit is protected by 3x2.5 mm² and a C16. The charred section is never patched; it is renewed all the way back to the board.

In the mid-age blocks of Esentepe and Hürriyet the riser feeding the flats from the meter panel was dimensioned years ago for far lower demand. On the upper floors the voltage falls to as low as 198 volts in the evening; the boiler cannot ignite, the refrigerator compressor labours and LED lamps flicker. That flicker is not a lamp fault but a clear symptom of voltage drop.

Our crew measures voltage at the riser head and at the flat intake under load, then calculates percentage drop from run length and cross-section. Where it exceeds five percent, an upgrade of the riser to 4x16 or 4x25 mm² NYY cable is presented to the management with the measurement report; as an interim step the loads are balanced across phases.

In Çavuşoğlu and Orhantepe a loosening main neutral terminal is one of the most insidious faults. As neutral resistance rises, the voltage on one phase climbs above 250 volts while another falls to 180. The result is a television, modem, boiler board and refrigerator board all failing on the same night. Customers assume a grid fluctuation, yet the fault is inside the building and is easily proven by measurement.

The repair opens every neutral connection downstream of the meter, cleans oxidised surfaces and torques the terminals to the manufacturer's figure. An over/undervoltage protection relay and a Type 2 surge arrester are added to the main board so appliances survive the next neutral loss.

Across Kartal the most common night call 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 lies in the installation. Branches are then energised one at a time until the offending leg is identified for certain. This method avoids blind part swapping and pinpoints the faulty circuit in about twenty minutes.

The faulty leg is measured with a megohmmeter to separate leakage caused by damp, by charred insulation or by a defective appliance. If an appliance is to blame it is disconnected and the home re-energised; if the wiring is at fault that leg is isolated, the remainder restored immediately and an appointment set for permanent repair.

In the markets, butchers and restaurants along Petroliş and Uğur Mumcu, the illuminated sign circuit is often wired in parallel with the interior lighting. When an LED module inside the sign takes in water and leaks to earth, the entire shop loses power and the refrigeration cabinets stop. In summer that outage means serious stock loss within a few hours.

In the commercial board, refrigeration, signage and general lighting are split onto three separate legs, each with its own residual current device, so a sign fault no longer stops the cabinets. The sign feed is renewed with an IP66 junction box and UV-resistant cable, and a phase protection relay is added to the cabinet circuits.

Every terminal inside the board is tightened with a calibrated screwdriver to the torque printed in the manufacturer catalogue, between 2.5 and 3.5 Nm. Hand tightening leaves an invisible slackness and residual contact resistance; current crossing that resistance carbonises the copper surface, resistance climbs further and a thermal runaway chain begins. As the chain advances the terminal passes 200 degrees, melts cable insulation and ignites the Bakelite enclosure.

On completion the whole board is swept with a FLIR thermal imager, not just the replaced component but every breaker, the residual current device and all busbar links. Latent hotspots above seventy degrees are located and re-torqued, which stops the customer facing the same fault again a few days later. The sweep is carried out under load, because heating is invisible in a de-energised board and the fault stays hidden. In older boards containing aluminium conductors the terminals are diarised for a further check after six months, since aluminium cold-creeps and works loose again over time.

In buildings with no protective earth, bridging the neutral pin to the earth terminal inside a socket is known on site as bootleg grounding. The moment the upstream neutral loosens or breaks, full 220 V phase potential energises the washing machine, dishwasher and oven chassis, and anyone touching the steel sink or appliance is placed directly across the mains. Such a setup can look faultless for years, then kill after a single loosened screw.

Our intervention removes every jumper one by one, drives a solid copper earth electrode, adds an earth busbar to the main board and commissions a 30 mA Type A residual current device whose trip time is verified in milliseconds with a dedicated tester. Removal of every jumper is additionally proven by measuring neutral-to-earth voltage at each socket, since one missed outlet keeps the hazard alive. Chassis continuity on metal-bodied appliances such as washing machines and dishwashers is also measured to confirm they are genuinely bonded to the protective conductor.

In a Soğanlık flat, flames and smoke were reported from a multi-way extension block in the laundry room. Reaching the address in twenty-one minutes, our crew found the tumble dryer and washing machine fed from a single 2.5 mm² run with the socket body entirely melted. Power was isolated and the burnt socket plus charred cable stripped out back to the board. Two separate unbroken circuits were pulled to the laundry room: 3x4 mm² on a C20 for the dryer and 3x2.5 mm² on a C16 for the washing machine. Both were placed behind a 30 mA Type A device and handed over after running the two appliances together with current readings taken.

On this callout the root cause was recorded with photographs and a thermal image, each step of the work written onto the service report and handed over against the customer's signature. Labour carries a 1 year guarantee.

In a Çavuşoğlu apartment block, televisions, modems and boiler boards failed in three flats on the same night. Our crew arrived in twenty-three minutes and found the main neutral terminal in the meter panel oxidised and loose. Measured under load, phase one read 251 volts and phase two 183 volts, the classic signature of neutral loss. Every neutral connection was opened, oxide cleaned, terminals torqued to 3 Nm, and an over/undervoltage protection relay plus a Type 2 surge arrester fitted in the building main board. The final reading showed a balanced 228 to 231 volts across all three phases.

On completion socket earth continuity and loop impedance were measured, the residual current device tested twice via its own button and an external instrument, then the system was safely re-energised.