Check to see that the generator and motor brushes
are in place and that they fit properly.
5. Before starting the motor, insulate the
electrode holder from the ground and attach the
work and electrode welding leads to the proper
generator terminals. On machines equipped with
reversing switches, connect the ground (or work)
lead to the terminal marked GROUND and the
electrode lead to the terminal marked
ELECTRODE. Then set the reversing switch for
the desired polarity. On machines not equipped
with reversing switches, connect the leads to the
terminals in the manner indicated on the nameplate
or in the manufacturer's technical manual. To
change polarity on these machines, interchange the
Figure 10-3.--Paralleling connection for a single-operator
6. Adjust the welding current according to the
manufacturer's instructions. Single-control machines
are designed to give adequate voltage at each
current setting. Dual-control machines have
The overload device does not hold the
separate voltage and current adjustments.
motor in the circuit.
Some values required for a given welding job
The machine fails to hold its amperage.
are beyond the capacity of a single-operator welding
generator. When this happens, the required current
The welding arc spatters excessively.
can be obtained by interconnecting or paralleling
two single-operator generators (fig. 10-3). As a
An Electrician's Mate is usually needed to
rule, the sets that are paralleled should be of
determine causes and to make repairs. However,
identical rating. However, it is usually possible to
there are some things that you can and should do
parallel sets of different ratings if you observe the
before you call in the Electrician's Mate.
proper precautions. If sets with different current
ratings are paralleled, take special care to ensure
If the machine fails to start, the trouble may be
an open or disconnected switch. You can check
machine ratings and that the current rating of
switches yourself. If the machine runs but will not
n e i t h e r machine is exceeded. Paralleling
generate current for the welding circuit, the motor
instructions are contained in the manufacturer's
may be rotating in the wrong direction. You can
technical manuals furnished with your equipment.
check the direction of rotation with the direction
arrow on the outside housing of the equipment. On
All dc generator welders should be located in
a three-phase motor, rotation may be changed by
clean, dry, well-ventilated places, away from acid
interchanging any two of the motor power leads.
fumes or steam. Given proper care, the unit should
Have an Electrician's Mate change the motor power
give many years of trouble-free service. Like most
leads if the rotation is wrong. If rotation is correct
mechanical devices, welding generators occasionally
and the machine still will not generate, the trouble
fail to operate properly. Common problems include
is elsewhere. You should call an Electrician's Mate
if the motor repeatedly cuts out of the circuit, or if
the machine does not hold its amperage after you
The machine fails to start.
ensure that all welding cable connections are tight
and that the unit is properly adjusted.
The machine runs but fails to generate
Excessive arc spatter may result from several
causes, such as arc blow, poor welding technique,