Tuzla

In the industrial plants of Aydınlı, Orhanlı and Tepeören, compressor, conveyor and pump motors are managed through variable frequency drives and PLCs. When the thermal setting of the motor protection breaker is not matched to the motor nameplate current, the motor is either left unprotected or stops needlessly during production. Contactor tips weld together under heavy inrush and a burning odour fills the enclosure.

The thermal setting is recalibrated to the motor nameplate current and a phase sequence plus undervoltage relay added. On circuits with a variable frequency drive, screened NYY cable is used with the screen earthed at one point only. A megohmmeter test is never applied to the drive output; readings are taken on the incoming side with the drive isolated. The PLC control circuit runs on a separate 24 V leg.

In the buildings near the Marmara shoreline of İçmeler, Şifa and Postane, outdoor boards, shipyard-area plant panels and garden junction boxes face constant salt humidity. Where the cable gland is loose, moisture travels straight down to the NYY cable end and oxide forms on the conductor surface. That oxide raises contact resistance, starts heating and lowers insulation resistance, creating leakage current.

Glands are tightened and their seals renewed, oxidised conductor ends cut back to clean copper and a protective conductive compound applied. The outdoor board is upgraded to a gasketed IP65 body with an anti-condensation heater inside. On seafront elevations, stainless steel or polycarbonate bodies are preferred over aluminium for luminaires and fixings specified in A4 grade stainless steel.

In the housing stock of Cami, Yayla and Mimar Sinan 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 behind the counter blackens. Because the board usually protects the whole flat with one 30 mA device, a single kitchen fault blacks out the entire home.

Kitchen loads are measured with a True-RMS clamp meter and the circuit split: 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. Blackened terminals are renewed and every connection torqued to specification.

Night calls in Tuzla come from both homes and industrial plants. In plants, an outage during a running shift means stopped production, so before any work the plant's technical officer confirms in writing which circuit may be isolated and for how long. The supply is secured with a lockout/tagout kit and the key stays solely with the technician doing the work.

On domestic calls, once the faulty leg is isolated the boiler, refrigerator and lighting are restored within the first ten minutes. If the residual current device will not hold, branches are separated one by one at the board and measured with a megohmmeter until the faulty leg is confirmed. No drill is used at night; location is done silently with a FLIR thermal imager and a cable tracer, and the permanent work booked for a daytime slot.

Apartment sub-boards receive switchgear rated at a minimum 6kA and building intakes 10kA breaking capacity. In a hard short circuit the prospective fault current reaches thousands of amperes within milliseconds; budget 3kA devices cannot quench that energy, weld their internal contacts together and rupture, throwing hot fragments outward. Breaking capacity is read from the boxed figure printed on the breaker body.

Protection stages are cascaded selectively: a 30 mA Type A life-safety device in the flat board and a 300 mA time-delayed Type S fire protection unit at the building intake. With that cascade a single socket leak trips only the affected flat instead of blacking out the whole block, while melting cable insulation is cleared by the 300 mA device before a fire starts. The cascade is built not on current threshold alone but on tripping time as well; delaying the upstream stage guarantees the downstream one opens first. After installation the trip current and trip time of both devices are measured with a dedicated tester and the values written onto the service report.

When water from the floor above fills a concealed conduit and ceiling junction box, the wall surface itself becomes conductive and touching damp masonry or a metal back-box carries a fatal shock risk. Keep clear of the board, isolate power at the building intake, then branches are isolated one by one with a digital megohmmeter, dielectric drying is applied and insulation resistance re-measured.

In wet rooms such as bathrooms and kitchens, socket and junction ingress protection is raised to IP54, and outdoors on balconies and in gardens to IP65; box interiors are encapsulated with dielectric silicone gel so moisture contact is permanently eliminated and the residual current device stops tripping. A soaked circuit is never re-energised before it dries; drying continues until insulation resistance reads at least 1 Megaohm. Where the water originates on the floor above, no electrical repair lasts until the plumbing is fixed, so the building management is notified in writing.

At a manufacturing plant in Aydınlı, the protection breaker on a compressor motor was reported to trip repeatedly during shifts, stopping production. Arriving in twenty-nine minutes, our crew secured the supply with a lockout/tagout kit and obtained written outage approval from the plant's technical officer. The motor nameplate rated 18.5 amperes while the breaker's thermal setting had been left at 14; the motor exceeded that threshold even at normal load. In addition, the contact face on one phase of the contactor was scorched by inrush and its contact resistance had risen. The thermal setting was recalibrated to the nameplate current, the scorched contactor replaced and a phase sequence plus undervoltage relay added. The panel was handed over after a thermal sweep under load.

The burnt components removed during the callout were shown and handed to the customer, while the box and barcode of the original switchgear fitted in their place were attached to the service report. All work is under a 1 year guarantee.