Ümraniye

In the İMES and DES industrial estates of Dudullu and Şerifali, forklift battery chargers run all night. These rectifier-based loads inject heavy harmonics into the supply and stress the power capacitors in the compensation panel. Capacitors bulge, the step contactor tips weld together under inrush and a burning odour fills the enclosure.

Our crew secures the supply with a lockout/tagout kit, discharges the capacitors and fits a dedicated capacitor-switching contactor with discharge resistors. Total harmonic distortion is measured with an analyser and a detuned reactor recommended where the ratio is high. The charging station circuit is separated from workshop lighting and fed by its own NYY cable from the board.

In the five-storey apartment stock of Yamanevler, Çakmak, İnkılap and Ihlamurkuyu, the kitchen branch runs off a single 16 A breaker. When the built-in oven, dishwasher and water heater work together in the evening the circuit saturates; the breaker trips thermally or the terminal inside the socket box blackens. The hall cupboard board usually protects the whole flat with one 30 mA device, so a single kitchen fault blacks out the entire home.

The repair measures the kitchen loads and splits the circuit: a separate C16 for the oven, another for the dishwasher and a 3x4 mm² run on a C20 for the water heater. The board is upgraded to a modular DIN-rail enclosure with lighting, sockets and wet rooms on separate devices. A fault then isolates only its own leg instead of the whole flat.

In the newer complexes toward Finanskent, Esenkent and Parseller, the load per flat has risen sharply over the years with air conditioning, tumble dryers and electric vehicle charging. The shared riser feeding the floors from the meter panel was never dimensioned for that demand, so it heats up in the evening; carbonisation starts at the busbar terminals and voltage sags on the upper floors.

Voltage and current are measured under load at the riser head and the flat intake, and busbar temperatures swept with a FLIR thermal imager. Carbonised terminals are renewed with fire-rated ceramic blocks and torqued to specification. Where voltage drop exceeds five percent, an upgrade of the riser to 4x25 mm² NYY cable is presented to the management with the measurement report.

The most frequent night call in Ümraniye 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. Branches are energised one at a time until the faulty leg is confirmed. Because no drill or breaker is used at night in terraced blocks, location is done silently with a FLIR thermal imager and a cable tracer.

Once the faulty leg is isolated, the refrigerator, boiler and lighting are restored within the first ten minutes. A dead boiler on a winter night is a serious risk in households with children or elderly residents, so the boiler is afterwards always moved to a dedicated circuit. Noisy chasing and breaking work is booked for the next working day and the temporary line left safely inside fire-retardant trunking.

At the end of every job the circuit is measured with a 500 V megohmmeter; if phase-to-earth insulation resistance falls below 1 Megaohm the cable is pulled anew rather than patched. Earth loop impedance is measured at socket outlets to prove the protective device clears a fault inside TS IEC 60364 disconnection limits. During testing phase, neutral and earth are read separately, and any voltage between neutral and earth triggers a search for a bootleg ground jumper.

Earth electrode resistance is measured with a digital earth tester; when the 2 Ohm target is missed an additional rod is driven or bentonite backfill applied. Every recorded value is written numerically onto the service report, handed to the customer and kept on file, so readings can be compared at the next inspection.

If a sharp Bakelite odour or smoke comes from the board and it is not yet in flames, trip the main switch using a dry wooden handle. Never pour water onto switchgear or a burning cable; water conducts, intensifies the arc flash and electrocutes the person intervening. Use only a Class ABC dry chemical powder or carbon dioxide extinguisher.

Never grab an electrocuted person bare-handed; the current passes into the rescuer too and leaves two people across the circuit. Separate the casualty from the source with a dry broom handle, a leather belt or a wooden chair, call the emergency ambulance number, then alert our 24/7 emergency electrician line. Even if the casualty is conscious and says they feel fine they must still attend hospital, because current that has crossed the torso can produce a cardiac rhythm disturbance hours later. Once power is off the board cover is closed and nobody attempts to reset the lever until the electrician arrives.

At a metalworking shop in Dudullu, a bang and heavy smoke from the compensation panel were reported at 02:20. Our crew reached the address in twenty-eight minutes. With the supply secured by a lockout/tagout kit, the third step power capacitor was found split open and the step contactor tips welded together. Harmonic analysis showed fifth order content at twenty-nine percent, injected by the forklift chargers. The ruptured capacitor and welded contactor were removed and replaced with a discharge-resistor capacitor contactor and a harmonic-rated capacitor. The reactive power controller was re-set and the panel handed over after a thermal sweep under load.

At the end of the callout line insulation resistance was re-measured with a megohmmeter, the values entered on the technical service report and a copy left with the customer. Fitted components carry both the manufacturer warranty and our 1 year labour guarantee.