`Upside-down` contactor needs 20% less space

ABB Control claims to have cut the space needed for motor starter assemblies by at least 20%, simply by reversing the conventional practice and putting the coil at the top and the contacts at the bottom of the contactor. It says that this change has led to a single, uniform starter system with direct connection between contactors, circuit-breakers, switchfuses and overload relays.

ABB adds that the new A series contactors are also quicker and cheaper to install, and should be safer and easier to maintain because the moving and stationary contacts are separated when the housing is opened for inspection.

The new design is the result of five years of collaboration between various ABB companies across Europe to come up with a harmonised design for switchgear and controlgear products. Traditionally, the various components needed to form a motor control centre have come from different companies with no standardisation of terminal positions, making wiring difficult.

The new contactors have rear or lateral terminal connections and shrouds, allowing them to connected directly, side-by-side or in-line, to other ABB components such as circuit-breakers and switchfuses.

Initially, the contactors are available in 145-300A ratings - equivalent to motor ratings from 75-160kW. This will be extended up to 750A (400kW).