Aydınlı Yolu Caddesi

Aydınlı Yolu Caddesi drops through Kaynarca Mahallesi toward Tuzla–Aydınlı. On it stand 1990–2015 sites, a ground-floor grocer of the A101 class, a pharmacy, a barber, a small office and a few-storey commercial block. It is in walking distance of Kaynarca metro; the evening load ends on the lift, the stair LED and the window strip. The call usually arrives as 'the shop went dark, the upper floor is still up'. That is not a D-100 window on Ankara Caddesi and not a lathe line in Sanayi Mahallesi. The job here is the neighborhood riser, the flat panel and the shop's sub-board.

In a ground-floor shop the sub-board often sits behind a store shelf or in the window ceiling: 6–12 C-curve MCBs, one 30 mA residual-current device, sometimes a separate air-conditioner switch. A window stolen from the site riser trips the common breaker at night. On a survey I read the shop meter first, then the sub-board, then the site stair. If there are two meters, two survey sentences are written. A tenant who calls as 'the upper floor tripped' may have burnt their own 16 A branch. If the label is gone a body is not fitted as 'the same'. Schneider Acti9, Siemens 5SL and Legrand DX3 want different torque on the same rail.

On Aydınlı Yolu the shop and the flat often carry separate 30 mA residual-current devices. Putting the two on one relay darkens the whole stair when a wet store pump trips. The RCD sees phase-neutral imbalance; the C-curve MCB sees a long current. Wet laundry, a punctured heater, a damp store and an LED driver without a ferrule trip the 30 mA. The first reflex of upsizing the MCB is the wrong habit on this cadde too. The measurement is insulation, loop impedance and leakage on the clamp. A mixed neutral-earth is common in a 1990s Kaynarca site; the terminals are read before the relay is swapped as 'broken'.

The sub-board incoming is NYY. If the store is wet, the eaves drip, or the garden run goes outdoors, it stays NYY. NYM is a dry indoor ceiling cable; it does not drop onto an oily store wall or into a wet window void. NYA is a single core for the busbar and the ferrule inside the panel; it is not buried under the screed. The fault I see often in Kaynarca is splicing a 3×6 NYY end-to-end with a 3×10 as 'too small', tightening without a ferrule, guessing the torque by hand. A 10 mm² NYY is not sold as 16 mm². An extension under a carpet is not a grocer-window fix. The cross-section is not upsized before the clamp-meter ampere and the label are seen.

In a Kaynarca site the stair LED is a sensor fitting and emergency lighting is a charged fitting. When the battery dies the fitting stays dark; that is not a riser outage. If the exit sign is not always lit, the driver or the battery is finished. Jamming the two into the same box also kills the emergency line when the sensor drops. If the common-area time clock (astronomical relay) is early, the window and the stair light together and the sub-board runs hot. If the meter room is locked the survey opens it with site management; I do not break a lock.

In an old Kaynarca site there is no earth rod, or it is rusted; a green-yellow wire screwed to the panel lid is sold as 'there is earth'. The measurement is loop impedance and rod continuity. Without a rod, a neutral-earth bridge blinds residual current. The main switch after the meter is often 3×40; the shop sub-board drops on 3×10 or 3×16 NYY. An RCBO is a single slot in a new flat panel; an old site still has a separate RCD plus a C-curve MCB. I do not mix the two on the same rail. A surge arrester is a separate talk on a site near the metro; a body is not chosen before the label is read.