Where a 100 A MCCB is used

Sub-main distribution from a main board

Motor feeders and motor control centres

Outgoing ways on a panel board where an MCB is not rated highly enough

Why MCCBs are adjustable

Unlike a miniature circuit breaker, an MCCB trip unit can usually be set. That allows the protection to be matched to the cable and to the fault level at that point, and to be coordinated with the devices upstream and downstream.

Selection points

Frame size and rated current

Breaking capacity at the point of installation, which must exceed the prospective fault current there

Thermal and magnetic setting range

Accessories required: auxiliary contacts, shunt trip, undervoltage release

Coordination with the incoming device so that a downstream fault trips only the downstream breaker

Pricing

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.