Examine all the wires; the insulation may have
worn through and two of them may cross, or be in contact with the frame or
other part of the welder. A short circuit in the regulator winding is
indicated by failure of the apparatus to regulate properly, and sometimes,
though not always, by the heating of the regulator coils.
The remedy for a short circuit is to reinsulate the defective parts. It is
a good plan to prevent trouble by examining the wiring occasionally and see
that the insulation is perfect.
_To Locate Grounds and Short Circuits in the Secondary, or Low Voltage
Side._--Trouble of this kind is indicated by the machine acting sluggish
or, perhaps, refusing to operate. To make a test, it will be necessary to
first ascertain the exciting current of your particular transformer. This
is the current the transformer draws on "open circuit," or when supplied
with current from the line with no stock in the welder dies. The following
table will give this information close enough for all practical purposes:
K.W. ----------------- Amperes at ----------------
Rating 110 Volts 220 Volts 440 Volts 550 Volts
3 1.5 .75 .38 .3
5 2.5 1.25 .63 .5
8 3.6 1.8 .9 .72
10 4.25 2.13 1.07 .85
15 6. 3. 1.5 1.2
20 7. 3.
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