Electrom Instruments High-Voltage Surge Testers and Winding Analysers for Rotating Equipment and Transformers

Electrom Instruments has supplied high-voltage surge testers and winding analysers worldwide since 1986. We specialise in portable surge testers that safely detect weak or unstable insulation in coils and windings. The non-destructive tests meet accepted international standards. The testers are used for both AC and DC rotating equipment with operating voltages up to 13,800V. They are also used for transformers and in transmission line applications. The highest outputs we have provided in a hipot and surge tester so far is 150,000V.

Surge tester and winding analyser

The iTIG surge tester and winding analyser is a:

• High-frequency surge tester: 50Hz or 60Hz surge pulse rate; surge tests assembled motors without turning the rotor; two surge generators for improved fault-finding
• DC hipot tester
• Megohm and PI tester
• Armature tester – low impedance
• Form coil tester – low impedance
• AC rotor tester
• Meets IEEE 522-1992 and IEC 34-15 standards for surge rise time

The iTIG surge tester and winding analyser is used for preventative and predictive maintenance of motors, generators, transformers and coils; and for quality assurance when manufacturing, rewinding or reconditioning equipment. It is also used to detect two conditions — weaknesses and shorts in windings and coils:

• To ground
• Turn to turn
• Coil to coil
• Phase to phase

The iTIG surge testers will detect shorts and weak insulation in high and low impedance coils; assembled motors (without turning the rotor); stators; armatures, shunts, interpoles and series fields; form coils; transformers; and many more.

They can also test for damage in AC rotors while the equipment is running.

Benefits of a surge tester / winding analyser

The iTIG surge tester / winding analyser finds faults or insulation weaknesses where other surge testers do not. Many surge testers have one surge generator or channel. This means one winding is tested and compared to a stored surge test of another winding or phase. The Electrom iTIG uses two independent surge generators operating simultaneously to compare two windings or coils. This produces a live surge comparison with a higher voltage gradient between the two phases under test, and a better simulation of rotating equipment operation.

High-frequency surge test pulses: ionisation of air surrounding the windings is necessary for detection of insulation weaknesses in a surge test. The iTIG generates line frequency surge test pulse rates (50Hz or 60Hz). This produces and maintains sufficient ionization around fault locations at lower test voltages than instruments with lower surge pulse rates, and duplicates conditions seen by rotating machinery.

It is estimated by industry associations that about 80% of insulation faults start with a turn to turn weakness. A megohm meter is mainly used to measure contamination levels in rotating equipment by measuring mega ohms to ground. A hipot test determines the dielectric strength of the insulation system to ground. Neither a megohm tester nor a hipot tester finds turn to turn, coil to coil or phase to phase shorts or insulation weaknesses found by a surge tester.

Easy-to-use surge testers

The iTIG surge tester is easy to use. It features a large color LCD touch-screen display, which provides large displays of test and output voltages, resistance (Megohms) and leakage current. It is possible to communicate with and adjust the iTIG surge tester through the touch screen, with a remote mini keyboard included, or with any standard USB mouse / keyboard.

Other ease-of-use features include:

• Easy retrieval of data and screen pictures
• Print reports from the iTIG or a PC
• Computer-controlled functions
• Status messages tell the user what is going on

Unlimited data storage is available. Customer information, equipment S/N, specifications, location, etc., and test data can be stored in the iTIG computer and transferred to other devices. 

Upgradeable surge testers

With the iTIG surge tester you only need to purchase the features you need now; upgrade later (in the field) if needs change. Choosing the right surge tester is easy since the number of models is limited, and all models can be upgraded in the field later to any higher level through software downloads. You are never stuck with the wrong surge tester.

Portable power pack

The iTIG will test motors with up to 5,000V operating voltage. Power packs are needed to test large and high-voltage rotating equipment such as large slow speed 4,160V to 13,800V electric motors and generators. Power packs with outputs up to 30kV come in the same rugged case as the iTIG.

Power packs with outputs of 40kV, 50kV, 60kV and up to 150kV are available in larger enclosures.