2.
Wiring Method
ao
Non-metallic-sheathed cable was specified for most lighting
branch circuits, and, for economy, standard service-drop
cable for overhead services.
Where protection against moisture or injury was required,
aluminum conduit and fittings were specified for overhead
installation,
All wiring concealed in concrete walls or floors or underground, where direct-burial cable was not used, was specified as "TW" wire in hot-dipped galvanized conduit.
Conduit, where required, was hot-dipped galvanized for
concealed work and aluminum (when available) for exposed
work,
Flexible conduit connections were only used for short connections from outlets to meters and consisted of flexible
steel conduit covered with a neoprene jacket to reduce
corrosion.
Power wiring was installed in rigid, hot-dipped, galvanized
conduit and metal boxes (aluminum when available).
Steel
boxes, where installed on aluminum surfaces, were insulated
by mounting on plywood fastened to the aluminum structure.
This was done to eliminate electrolytic action that would
otherwise cause accelerated corrosion. Where conduit was
installed exposed, it was aluminum (when available) and
was fastened to the structure with aluminum straps, bolts,
etc,
Overload
a.
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Circuit breakers were specified for circuit protection in
the majority of installations. Breakers were the thermalmagnetic type.
Lighting panels, which proved very satisfactory, were the
MB or MO type. Most power panels were type MH, ML or ABQ,
except in certain specific instances such as the laboratory
building on Japtan. At this location, fused power panels
were installed to permit easy increase or reduction of
circuit capacity (changing fuse sizes) to suit changing
requirements of laboratory equipment within the limits of
wiring provided. Because of changes in construction schedules and slow delivery of panels on order, field changes
were required. These changes involved the use of panels
for buildings other than those for which they were ordered.
In order to accommodate these panels and to avoid delay in
construction, plans were revised as required.
5-126