(B, fig. 3). Existing connections should
not be changed.
3 gives similar information for gaseous and slag types of
(2)
All connections must be made before
electrodes.
starting either set and they should not be
broken until both sets are shut down.
Table 2. Current Setting Range for Bare or Lightly
Coated Electrodes
(3) Reversing switches must indicate the same
Electrode
Current
Electrode
Lengths
polarity at ail times, and must never be
diameter
minimum
maximum
(in.)
(in.)
(Amps.)
(Amps.)
changed if either set is running.
(4) Electrode selectors should indicate the
3/32
70
90
11 1/2
1/8
110
135
14 or 18
same electrode size so as to divide the
5/32
150
180
14 or 18
load equally between the two generators.
3/16
150
220
14 or 18
(5) Current selector dials should always indicate
1/4
250
300
14 or 18
the same current, otherwise it will be difficult
5/16
300
425
14 or 18
to adjust for the desired current, and one
3/8
450
550
14 or 18
rheostat might become overloaded.
Warning: Do not attempt to weld with
Table 3. Comparison of Current Used with Gaseous
two welding sets in parallel unless both
and Slag Types of Electrodes
are running. Both must be started and
stopped simultaneously, both driving
Electrode
Gaseous types
Slag type
motors must be on the line, or both off.
diameter
flat position
Do not make or break any connections
(in.)
(amperes)
while either set is running.
Flat position Vertical and
(amperes)
overhead
29. Operation Under Unusual Conditions
position
a. Operation in Extreme Cold (Below 0oF.).
(amperes)
(1) Before starting the welding machine,
3/32
60
60
1/8
120
110
130
disconnect its source of power and wipe the
5/32
150
140
160
electrical components free of ice and
3/16
175
160
200
moisture. Do not disturb the wiring as it
1/4
200
300
becomes brittle with extreme cold.
5/16
325
400
(2) Connect the power source.
3/8
425
500
(3) Start welding machine (para 26).
(4) Begin usual welding operations (para 28).
g. Strike an arc.
b. Operation in Extreme Heat.
(1) Erect a shelter to shade the machine and
h. If the arc is weak, turn the electrode selector one
provide as much ventilation as possible to
setting higher. If the arc is too cold turn the rheostat
keep operating temperature of the welding
current selector up and turn the electrode selector down.
machine as low as possible.
Warning: Do not adjust welding controls while
(2) Connect the power source.
maintaining arc.
(3) Start the welding machine (para 26).
(4) Begin usual welding operations (para 28).
i. Parallel Operation.
c. Operation in Dusty or Sandy Areas.
(1) Two welding sets of the same type and
(1) If the installation is to be permanent,
rating can be operated in parallel to obtain
provide protective cover to keep the unit as
twice the capacity of one set. When
clean as possible paying special
connecting welders together for parallel
operation, it is necessary to use two
paralleling and two equalizer connections
AGO 8244A
14
