big 40 no AC power

[joel.richeme]

got a big 40 with non working AC power. i have 20Vac at the receptacle. i checked both bridge rectifier and theg are ok. according a schematic i have there should be a varistor in the circuit but it's missing. also i disconnected a some sort of exciter circuit connected at the positive terminal of both positive terminal of the bridge rectifiers. also i check the resistance of both windings and i have 18.7 and 48.6 ohm.
anyone got a clue ??

[joel.richeme]

just tested it and im able to strike an arc no problem.

[Welderearl]

got a big 40 with non working AC power. i have 20Vac at the receptacle. i checked both bridge rectifier and theg are ok. according a schematic i have there should be a varistor in the circuit but it's missing. also i disconnected a some sort of exciter circuit connected at the positive terminal of both positive terminal of the bridge rectifiers. also i check the resistance of both windings and i have 18.7 and 48.6 ohm.
anyone got a clue ??

Try going to the voltage regulator a clear plastic with 3stes of contacts. clean the contacts

[joel.richeme]

im pretty sure my welder doesnt have that. its an old style with a 300w rheostat

[joel.richeme]

anyone ?

[Aeronca41]

Please post serial no.

[joel.richeme]

airco superhornet 300 HF862539

[cruizer]

Take a resistance measurement from the black (short spade) terminal on the receptacle to frame ground. Is it less than say 50 ohms. if greater, you have a open somewhere.

[joel.richeme]

ill take some mesurements tommorow morning

[joel.richeme]

open circuit on the auxiliary power windings