A passive box has no motor and no power, so inspection takes the place of maintenance: an uninspected box quietly loses insulation. Hang the calendar where the box is washed and the check needs no separate stop.
| Frequency | Check |
|---|---|
| Every use | Lid closing, latch seating, cuts or ice on the seal, new body damage, washing and drying |
| Monthly | Deep scratches on the inner surface, castor rotation and bolt tightness, legibility of labels |
| Half-yearly | Rust on hot-dip galvanised steel rails, play in the hinge and corner joints, a day-long cold room test with the box empty |
| Annually | ATP validity date, spare parts stock, box file, retirement decisions |
The ATP date is a line of its own
Under the Turkish regulation, equipment in service is inspected periodically within 6 years of manufacture; a positive result is valid for 3 years, or 6 if the type test is repeated. The equipment owner books the appointment, a crash or impact calls for an exceptional inspection, and dense-insulation equipment older than 15 years is treated as normal insulation.
The ATP certificate holds as long as the insulated body is kept in good condition and no material alteration is made. A series of empty-box measurements taken under the same conditions is the only numerical data on how the insulation is changing; each box's record carries serial number, date, finding, action and return-to-use approval.
