Remove electrical code violation of extension cord being used through ceiling space for work bench. Provide a dedicated, 20-amp, 120-volt circuit from the electrical panel to the workbench and install a receptacle.
Gave estimate for hot water heater solution Supply and install new 100AMP 3 phase disconnect Replace existing fuses with 65AMP fuses Run new dedicated circuit from panel to service disconnect Replace 3Ph breaker in panel to 100amp Work can not guarantee that water heater wont have additional problem with elements