Busbar Bridge Units
These are sections of overhead busbar bridge which link 2 different legs of a Motor Control Centre or Distribution Switchboard. The reason is usually to make maximum use of the available space within a switchroom, and the most common configuration is shown below:- 2 legs of an MCC facing each other.
The busbar system (copper and busbar support) within the bridge is identical to the main bars in the associated MCC or switchboard, with the same fault rating. Also carried through the bridge is the main earth bar and any associated control wiring, in a separate chamber, of course.
In some cases, space is really tight. The following board was installed in a container for easy installation at site:-
Or the units could be located back-to-back:-
These Air Circuit Breaker incomers are located back-to-back with a connecting bridge on top.
In the following example, it was required to leave a walkway through the MCC because of the layout of the room:-
This is not really a bridge, but a rear link between busbar sections.
The two incomers had to be located either side of a concete pillar, so a rear link was designed to pass around the back of the pillar, and a blanking plate fitted at the front to hide the concrete.
The design of the ODA pumping station on the site of the London Olympics required a curved board to fit around the shape of the inside of the building. Each link section is a wedge shaped bridge, which allows the whole board, when complete, to follow the curve of the room.