Products

Electromagnetic Core Imperfection Detection (EL CID) testing is accepted world-wide for reliable and safe detection of stator core inter-laminar faults (CIGRE, 2004)."

Originally developed by the CEGB in England, the EL CID Evolution is a third generation instrument that is proven, reliable and easy to use. The EL CID Evolution tests the condition of a stator core in less time and with fewer resources than the earlier EL CID models.

The ELCID instrument can be used to test turbo-generators, hydro-generators, and large motors.

EL CID Evolution Features Faster test scanning (up to 120mm/sec @60Hz) Easier excitation calculations Simpler testing with dual Chattocks User-friendly LCD display to guide user operation Ability to combine step-iron data with main core traces "Hot spots" color map display Fully compatible with existing data
EL CID Evolution Advantages Tests are repeatable Immediate test results are available for local analysis and emails Determines if defects are on the surface, under conductors, or sub-surface Tests with or without windings in place Allows partial retests of a core. Results can be merged to obtain a complete picture of the core condition Trending of previous results Excellent quality assurance test

EL CID operates at only 4% of normal operating flux. This low flux is generated by a portable, quickly installed excitation kit. Any imperfection in the core inter-laminar insulation produces fault currents, which are detected by a Chattock coil and analyzed by the EL CID signal-processing unit. Measurement results are digitally stored in a laptop for analysis and report generation to precisely locate the faults in the stator core. Future results can be compared to past results for trend analysis.

The Robotic Inspection Vehicle (RIV) compliments the EL CID Evolution, and is ideally suited to test large stator cores. Having the capability to follow automatically the edge of stator teeth, the RIV carries the Chattok, thereby significantly reducing operator fatigue. This also increases the speed of testing.

Powertest Asia offers EL CID generator testing services, as well as a complete training course on the use and operation of the EL CID Evolution instrument.

The Robotic Inspection Vehicle is a low profile (30 mm/11⁄4") magnetically supported robotic vehicle that can carry the Chattock of the EL CID stator core fault test equipment along the stator core of an electric generator or a large electric motor. The automated scanning at a fixed speed provides easier testing and more consistent results than an EL CID core fault test performed manually. Leading OEM's and power utilities have successfully used the RIV on large generators for EL CID testing and to carry other transducers such as mini-cameras and Wedge Tightness Detector probes.

Robotic Inspection Vehicle™ (RIV) Features Width adjustment via two lockable sliding bars Magnetically self supporting on steel surface Guidance system detects the edges of the stator teeth to follow a straight line Side plates give additional guidance when wedges are recessed or when wedges and coils are removed Curvature adjustment accommodates the tractor in stator cores of various sizes Distance measurement via encoder wheel Chattock sense coil is clamped into spring loaded shoes so that the ends of the coil press lightly against the core AUTO mode allows the RIV to stop at a pre-set distance and then move only in the opposite direction

The WTD-501 instrument is an improved version of the original WTD-123. Generator testing with the WTD-501 instrument quickly and objectively measures the relative tightness of all stator wedges in a machine. The redesigned probe is small, light and adjustable to fit most rotating machines, regardless of slot size or depth.

Stator Wedge Tightness Detector Features Accurate, reliable and consistent results assist in maintenance decisions to be reached Objective electronic analysis removes subjectivity of hand tapping Quick, easy collection and interpretation of data Easy to operate, experienced personnel not required

Stator wedges were traditionally tested for tightness by tapping them with a hammer and listening to the sound produced. Electronic stator wedge tightness detection is faster, more accurate, provides more consistent results than hand tapping methods, and the test procedure is repeatable. The WTD Model 501 can be used to test all types of generators and motor stator wedges, including those with ripple springs.

Loose stator wedges may lead to vibration and erosion of stator insulation in electric generators. These serious problems can cause generator failure. The WTD acts as a sophisticated electronic ear that quickly and reliably provides an electronic map of wedge tightness.

The tightness of each wedge is compared to all other wedges in the winding, the wedges of another winding or an absolute external reference. A colored map showing the relative tightness of every wedge in the stator is produced and the data can be stored for trend analysis to determine when maintenance will be required.

The DCR-50 instrument provides a safer off-line test of stator winding insulation compared to a DC or AC hipot test. It can identify problems in the stator winding insulation before an unexpected in-service failure, unlike the pass/fail of a dc or ac hipot test.

DC Ramp Test Set -- Model DCR-50 Features Ground Presence Detection and Protection Automatic Ramp or Manual Mode Ramp Rate Control (0-2.5 kV/min) Manual Voltage Control (0-50 kV) Automatic Trip Protection (high/low tracking, output limit, fault detection) Built-in Winding Discharge Circuit Voltage Metering (0-50 kV) Current Metering (0-250 µA, range switchable, charge and discharge) Analog and Digital Outputs for Voltage and Current Connection to a PC

An automatically ramped or manually stepped direct voltage (up to 50 kV) is applied to the stator winding and the resulting current is measured and plotted against voltage. Examination of the current versus voltage curve allows assessment of stator insulation condition, as well as diagnosis of damage, defects, and deterioration mechanisms. The DCR-50 allows tests to be performed in accordance with IEEE Std 95-2002.

The test results are repeatable and accurate. This test can frequently identify stator insulation windings that are approaching failure, without accelerating the deterioration process. It can take less than an hour to perform. The DC Ramp Test method has been proven for motor and generator insulation testing for many years by the US Bureau of Reclamation and others. It is applicable to asphalt, polyester and epoxy-mica insulation systems.

PDA Couplers specifically designed to detect partial discharge activity from hydro generator stator windings.

Whether it’s the epoxy-mica or cable type, these couplers are permanently installed at specific locations on the stator winding to optimize electrical noise / partial discharge pulse separation.

PDA couplers detect stator winding PD activity. In the last two decades Epoxy Mica Capacitors (EMCs) have become the industry’s choice due to reliability and the relative ease of installation. EMCs installation usually requires about 3 to 4 days of effort per machine. Typically, on machines rated less than 100 MW, only 6 couplers are installed. On large machines, sometimes more than 6 PDA couplers are installed. The standard package includes a set of 6 couplers, a termination box and installation hardware.

Stator Bus Coupler Stator Slot Couplers

Acquiring Partial Discharges TGA-B The TGA-B is a portable instrument specifically designed to monitor PD in motors and turbine generators equipped with Bus couplers. The TGA-B instrument determines the magnitudes, rates and polarities of voltage pulses created by partial discharges. Additional parameters such as NQNs and peak pulse magnitudes are also calculated. The instrument comes equipped with user selectable RS232, USB, or Ethernet (TCP/IP) communication modes. An external computer is used to acquire, display, and store PD test results quickly and conveniently. TGA-S The TGA-S is a portable instrument specifically designed to monitor PD in turbo generators equipped with Stator Slot Couplers (SSCs). The SSC approach to PD monitoring is a patented technology, exclusive to Iris. The TGA-S instrument determines the magnitudes, rates and polarities of voltage pulses created by partial discharges. Additional parameters such as NQNs and peak pulse magnitudes are also calculated. The instrument comes equipped with user selectable RS232, USB or LAN communication ports. An external computer is used to acquire, display, and store PD test results quickly and conveniently. PDA-IV The PDA-IV is a portable instrument specifically designed to monitor PD in hydro-generators equipped with PDA Couplers. The PDA-IV instrument determines the magnitudes, rates and polarities of voltage pulses created by partial discharges. Additional parameters such as NQNs and peak pulse magnitudes are also calculated. The instrument comes equipped with user selectable RS232, USB, or Ethernet (TCP/IP) communication ports. An external computer is used to control data acquisition, display, and store PD test results quickly and conveniently. Corona Probe The Corona Probe is an off-line instrument to accurately pinpoint the source of partial discharge (PD) in a particular slot in generators and motors. Complete kit comes with PPM-97 peak pulse meter, ferrite probe, ground strap and handy carrying/storage case.

The Corona Probe (originally known as the TVA probe) is used to locate partial discharge in each slot with the winding energized phase by phase. It supplements on-line partial discharge monitoring. The PPM-97 probe is generally used on motors and generators with rated voltage greater than 6 KV

The DCR-50 instrument provides a safer off-line test of stator winding insulation compared to a DC or AC hipot test. It can identify problems in the stator winding insulation before an unexpected in-service failure, unlike the pass/fail of a dc or ac hipot test.

• Flux Monitor

The Flux probe instrument is a sophisticated on-line monitor to remotely acquire magnetic flux data from air gap mounted flux probes in synchronous motor and generator rotors. Air gap flux monitoring is a proven tool used to provide information on the integrity of the rotor winding inter-turn insulation. This information is critical in planning maintenance, explaining abnormal vibrations and verifying new and rewound rotor integrity.

Traditionally, portable instrumentation has been used to acquire magnetic flux signals from probes permanently mounted on the machine stator. The Flux probe system consists of a permanently connected Flux probe acquisition device which is mounted in the plant and can be connected to probes from up to four generators.

This instrument includes user-friendly Windows™ acquisition software, which is used to store data from any of the four inputs on demand. Using generator load information, the Flux probe instrument can automate your magnetic flux measurements, freeing you from traveling to the plant, or having to be available during hard-to-schedule generator run-ups.