Lighting arrester tester

A portable tester for determining in the field the condition of a lightning arrester connected in parallel with a high voltage winding of a transformer, said tester comprising:

• a) a battery;
• b) an inverter being connected to said battery for generating an AC output;
• c) means for transforming the output of said inverter to a high voltage DC having a magnitude greater than the breakdown voltage rating of a lightning arrester connected in parallel to the high voltage winding of a transformer being tested;
• d) at least one capacitor being connected across said transforming means for being charged to the high voltage DC;
• e) means for discharging the high voltage charge of said at least one capacitor across the high voltage winding of the transformer being tested;
• f) said discharging means including an overvoltage spark gap switch connected across said at least one capacitor;
• g) means for detecting the response of the winding to the high voltage pulse;
• h) whereby a normally functioning lightning arrester will clamp the voltage across the transformer winding at the arrester's known breakdown level.

A device for generating and discharging a high voltage pulse across an electrical equipment being tested in the field, said device comprising:

• a) a battery;
• b) an inverter connected to said battery;
• c) at least one transformer being connected to said inverter for raising the voltage output of said inverter;
• d) a rectifier being connected to said at least one transformer;
• e) at least one capacitor being connected across said rectifier;
• f) spark gap switch means being connected across said at least one capacitor for discharging said at least one capacitor across the electrical equipment to be tested;
• g) means for connecting the output of said switch means to the equipment to be tested;
• and
• h) means for automatically isolating said battery from said inverter after a high voltage pulse has been discharged, thereby preventing recharge of said at least one capacitor.

A tester for determining the condition of a lightning arrester connected in parallel with a high voltage winding of a transformer, said tester comprising:

• a) a low voltage power source;
• b) means for transforming the output of said power source to a high voltage having a magnitude greater than the breakdown voltage rating of a lightning arrester connected in parallel to the high voltage winding of a transformer being tested;
• c) means for generating a high voltage pulse from the output of said transforming means and discharging the high voltage pulse directly across the high voltage winding of the transformer;
• d) means for detecting the response of the winding to the high voltage pulse;
• and
• e) means for automatically isolating said power source from said transforming means after a high voltage pulse has been discharged, thereby preventing said generating and discharging means from operating after the high voltage pulse has been discharged.