TM 9-4940-549-14&P
OFF position and that no equipment or appliance is
plugged into the 120-volt shop set receptacles.
Place the power selector switch in the EMERGENCY posi-
(b)
tion.
Connect the emergency power source by opening the ac-
(c)
cess door on the street side of the engine housing as
sembly and plugging in the EMERGENCY power supply
lead.
Observe the frequency meter and set the frequency switch
(d)
to either 50 or 60 hertz as indicated by the meter.
Place R3 circuit breaker in the ON position.
(e)
120-V power is available from R3 duplex receptacles ONLY.
(f)
Shop shop lights are also operational.
Operation with Power Selector Switch in OFF Position. To develop
d.
DC current for welding, when AC current for operating shop set is
not desired, turn the power selector switch (fig. 24) OFF. Then,
refer to figure 2-6, start the engine and accelerate to 1,800 rpm.
The required DC current is now available.
NOTE
Experience alone will enable the oper-
ator to determine the correct DC ampere
and polarity required for the particular
welding to be accomplished.
e.
Welder Operation.
NOTE
Refer to TM 9-237 for welding techniques.
Refer to paragraph a, and energize the system with internal
(1)
power; refer to paragraph b, and energize the system with
external power, or, refer to paragraph 25d.
(2)
Connect electrode and ground cable to dynamotor-welder output
terminals (positive electrode and negative ground) .
(3)
Place the polarity switch in the desired position.
(4)
Turn the DC ampere selector switch (fig. 2-4) so that the de-
sired amperes (welding) range is directly under the arrow of
the selector switch. The DC ampere fine adjustment rheostat
located in the center of the selector switch can now be adjusted
to the desired amperes within the range shown at the top of the
