Mersen ATDR4 Mersen Class CC Control and Motor-Circuit Fuses

The ATDR and ATQR references grouped here are Mersen Class CC time-delay fuses used in motor-starter, drive and control circuits. Mersen does not build variable speed drives; the classification reflects where these fuses are fitted, not what they are. Razz Middle East supplies them to order against the printed catalogue number, delivered duty-paid, three weeks from order confirmation.

Mersen ATDR4

This page covers Mersen part number ATDR4 — Mersen Class CC Control and Motor-Circuit Fuses. Quote the full part number with your enquiry and the item is unambiguous: one part number identifies one exact product variant, including options that are not visible in the description.

About Mersen Class CC Control and Motor-Circuit Fuses

Class CC is the small-body branch and supplementary fuse class used where a full-size fuse would waste panel space. Both ATDR and ATQR are time-delay members of that class, meaning they tolerate a short overload without opening, which is what a motor branch circuit or a control transformer needs at energisation. The digits after the letters give the ampere rating; ratings in this class run low, which is why these references show up on control circuits, contactor coils, transformer primaries and the auxiliary supplies around a drive rather than on the main power path. Class CC bodies carry a rejection feature at one end, so a holder built for the class will not accept a fuse of a different class in the same physical envelope. ATDR and ATQR are distinct catalogue lines with their own published characteristics, and although both are time-delay they should not be treated as drop-in equivalents without checking the curve against the circuit.

Mersen Class CC Control and Motor-Circuit Fuses in Saudi Arabia

These fuses live inside control panels, so they follow the panel-building practice of whoever supplied the equipment. Motor control centres and packaged skids built to North American standards for Aramco, SABIC and Ma'aden sites at Jubail and Yanbu are the largest population, along with imported process machinery, compressor packages and water-treatment control panels. On a drive installation they typically protect the control transformer, the fan supply and the auxiliary circuits rather than the drive input itself. Saudi control circuits are commonly derived from a 380/400 V, 60 Hz supply through a control transformer, so the voltage these fuses see is set by the transformer secondary and should be read off the drawing. Panels in outdoor kiosks and unconditioned switch rooms run hot inside, which is worth remembering when a fuse that has been reliable for years starts nuisance-tripping in summer.

Ordering and lead time

Quote the reference exactly as printed, including the hyphen where the catalogue number carries one, since ATQR-6 and ATQR10 are separate references and a missing character changes the rating. State the quantity, because these are consumables and are normally replaced as a set across the three phases. Confirm that the holder in the panel is a Class CC holder before ordering, and if the holder needs replacing, order it against its own reference. If you are protecting a circuit around a drive, tell us what the fuse actually feeds — control transformer, cooling fan, brake circuit or auxiliary supply — so the rating on the drawing can be checked before we quote. Sourced to order and delivered duty-paid, three weeks from order confirmation.

Specifications are taken from the supplier's published catalogue data. Confirm against the manufacturer's current datasheet before ordering.