Electric Wiring, 3rd Edition

Steel conduit 121

Where greater lengths of conduit are required than those supplied,

couplers are employed (Fig. 8.2). A running joint is used where it is

impossible to turn screwed conduit (see Fig. 8.3).

Conduit boxes

The chief

use

of these boxes is to facilitate drawing in wires by giving access to

them at sharp bends (Fig. 8.4). The internal diameter (60.3mm) renders them

unsightly for surface work for which the smaller inspection-type fittings,

such as elbows, tees and bends, are more suitable. On sunk and concealed

work, however, circular boxes are to be preferred. They are made in a

number of patterns

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two-way 'through', two-'angle' ...