(2) Disconnect air line to pressure gage (fig. 3-
e. Reassembly. Reassemble the drive motor as
(3) Tag and disconnect electrical leads from
f. Instal[ation. Install the motor (TM 5-4940-
225-12).
pressure switch.
(4) Remove two conduit locknuts and remove
3-3 Pressure Switch
pressure switch from the starter box.
a. Removal.
b. Installation. Install in reverse order of
(1) Remove screw
and remove
cover on
a above.
c. Adjustment. Refer to TM 5-4940-225-12 for
adjustment.
Figure 3-3. Air compressor pressure and starter control box, removal and installation.
(3) Remove conduit nut from elbow.
(4) Remove four screws and remove starter
a. Removal.
control box from bracket.
(1) Remove pressure switch (para 3-3).
b. Installation. Install in reverse order of
(2) Tag and disconnect electrical leads (fig. 3-
a above.
3).
Section II. DYNAMOTOR-WELDER
dynamotor-welder. The exciter, its commutator and
3-5. General
brushes, and the alternator, with its sliprings and
On-equipment electrical test procedures (para 3-9)
brushes, are located at the drive end.
determine the necessity and extent of electrical
Warning: Before performing any main-
repair of the dynamotor-welder. When making on-
tenance procedures on the electrical system,
equipment tests, refer to the practical wiring
see that all external power is disconnected from
diagram in figure 1 and figure 2. Note that the
the shop set and stop the truck engine.
direct current welder generator, commutator, and
brushes are located at the non-drive end of the
3-7