This page was a price list

The legacy version of this page published a price list. Prices are not reproduced here: brief §30 requires commercial data to come from supplied current sources, and the legacy figures carried no validity date. Send us your requirement for a current quotation.

Rating

The rated current follows the cable the device protects, after derating for grouping and ambient temperature — not the rating of the load plugged in at the far end.

Curve

Curve B — trips between three and five times rated current; suited to resistive loads and long cable runs.

Curve C — trips between five and ten times rated current; the general-purpose choice for mixed loads with moderate inrush.

Curve D — trips between ten and twenty times rated current; used for loads with high inrush, such as transformers and large motors.

Choosing too low a curve causes nuisance tripping on start; choosing too high a curve removes the protection the circuit needs.

Breaking capacity

The device must be able to interrupt the prospective fault current at its point in the installation. In a board fed from a transformer close by, the fault level can be far higher than in a domestic board.

Rated and rated unconditional

The two figures describe the device’s behaviour after clearing a fault at its rated breaking capacity. The distinction matters where the device may have to clear a full fault and continue in service.