equipment being tested. The grounding leads installed
in ships with wooden hulls should be the same as those
installed in ships with steel hulls except that the leads
should be secured to the ship's electrical grounding
system. A bare, solid-copper conductor, not less than
83,690 circular roils, must be used for the main internal
Test bench receptacle panels should be installed on
test benches where power at various voltages and
Figure 1-6.--Danger sign to he posted near electric
frequencies (other than ship's service) are needed for
workbenches, satisfy this requirement. The disconnect
switch must not be located on the workbench. The safe
for general-purpose workbenches and workbenches for
place to install the disconnect switch is away from the
the repair of instruments, such as typewriters and meters.
bench, between the entrance to the space and the bench.
A dummy outlet is installed near the workbench to
The required safety signs for a workbench must
check the grounding conductor on portable tools before
conform with General Specifications for the Overhaul
they are issued
of Surface Ships (GSO), Section 665. Signs that must
Workbench receptacle connectors should not
be posted include the following:
The sign shown in figure 1-6 must be posted near
workbench must be connected to a common or an
each workbench. This sign must be reproduced
locally on 0.05-inch aluminum engraved with red
be either 450/120-volt supplied from a 450-volt load
center or a 120/120-volt supplied from a 120-volt
A sign giving artificial respiration instructions
General Specifications for the Overhaul of Surface
(NSN 0177-LF-226-3400) must also be posted.
Ships (1991), Section 320, requires that a means of
A sign showing an approved method to rescue
disconnecting power be provided in the compartment in
personnel (fig. 1-7) in contact with energized
which the workbenches are installed. Distribution
panels, when installed in the same compartment as the
circuits. This sign is locally produced.
Figure 1-7.--Instructions for rescuing personnel in contact with energized circuits.