Not sure where you are getting those specs from. The small portable 115
volt units are rated at 1.5kva (1.5 kw) so expect 12.5 amp input current.

Page 10 of the Horrible Freight 115 volt spot welder
http://www.harborfreight.com/cpi/cta...emnumber=45689
shows amperage in the 2000 to 4000 amps range
http://www.harborfreight.com/manuals...5999/45689.pdf

The larger stationary units for industrial use are typically in the 15kw
and up (WAY up!).

Time Traveler wrote:
Reading the specs on a commercial spot welder for 115v it says output is
40 amps.Am I missing something from this spec?