MAINTENANCE OF POWER TOOLS
It is the task of a CE to ensure the proper operation
of all power tools within his or her realm of
responsibility. The program itself will be formulated by
higher authority. The best way to perform this task is to
develop a good inspection and maintenance program.
Periodically, you should check all power tools for loose
connections, pitted contacts, improper mounting of
switches, and so forth.
The inspection and maintenance of power tools go
hand in hand, and, in most cases, a problem discovered
during inspection is corrected on the spot and requires
no further work until the next inspection.
Test equipment and experienced Construction
Electricians are not always needed to locate problems.
Anyone who sees a ground wire dangling beneath a
lightning arrester might suspect a problem. Little skill
is required to consider an electrical service problem as a
possible reason for the lack of power in a building.
Arcing, loud noises, and charred or burned
electrical equipment sometimes indicate electrical
faults; however, hidden, noiseless circuit problems are
much more common and usually much harder to locate.
The right test equipment and the Construction
Electrician who knows how to use it are a valuable
combination for solving electrical circuit problems.
No attempt will be made in this chapter to explain
the internal workings of test equipment, such as meter
movement or circuitry. Information on these subjects is
covered in Navy Electricity and Electronics Training
Series (NEETS) modules, published by the Naval
Education and Training Program Management Support
Activity. Test equipment is discussed in Modules 3 and
16. Your education services officer (ESO) should stock
the NEETS modules. If not, he or she can order them for
you. Other information on the use of test and circuit
measuring equipment is included in modules
throughout the NEETS series. This section introduces
to you the types of test equipment used by the
Construction Electrician in the field.
Naval Facilities Command (NAVFAC)
requires that tests of electrical equipment be
performed under the supervision of qualified
electrical personnel. If in-house personnel are
not available for these tests, the services of a
qualified electrical testing contractor may be
used. If you do not know how to do certain tests
that must be performed, go to your seniors
(crew leader and/or project chief). Be certain
that you can perform the test safely before
starting the test procedure.
A meter used to measure the flow of electric current
is a current meter. Current meters that measure current
in amperes are called ammeters. The ammeter is
connected in series with the circuit source and load.
Panel-mounted ammeters, such as those used in power
plants, are permanently wired into the circuit. Figure
7-17 shows two typical panel-mounted ammeters.
Portable ammeters are temporarily connected into a
wiring system at whatever point in the system a current
reading is desired; for example, feeder current is
measured by opening the feeder and wiring the meter in
series with the feeder source and load. Circuits
branching off the feeder may be opened and an ammeter
inserted into the branch.
Using a clamp-on ammeter (fig. 7-18) is an
exception to the rule previously stated requiring
ammeters to be series-connected. The clamp-on
ammeter consists in part of clamp-on transformer jaws
that can be opened and placed around a conductor. The
Figure 7-17.Typical panel ammeters.