CT / PT testing

CT / PT testing

Our testing methods are set by national and international standards. The relevant standards subdivide the instrument transformers into classes, for which the ratio error and phase angle are specified. The ratio errors are defined by the relative deviation of the measured amplitudes of the current- or voltage vectors from the nominal values. The phase error is the phase angle of the output minus the phase angle of the input, for a sinusoidal input and output at a fixed frequency.   As well known, phase angles will contribute to the measured values of power and thus also the energy. To verify both types of errors, reference standards are necessary, the measuring uncertainty of which is much smaller than those of the devices to be tested.   Series – W Automatic current and potential transformer test set ED-00CR Low voltage unit for capacitive voltage divider Burden Artificial load for voltage and current transformers Current Transformer Standard current transformer

Series – W

Series – W

Automatic current and potential transformer test set for testing ratio error and phase displacement of instrument transformers. uncertainty of measurement 10ppm / 10urad broad range of corrections display of the results in all accepted dimensions remote controll and data transfer via RS232 interface Standard and Metrology variants available: CT + PT CT PT Technical Data Standard version Technical Data Metrology version

ED-00CR

ED-00CR

Low voltage unit for capacitive standard divider. This instrument together with a compressed gas capacitor replaces standard potential transformers broad range of division: 5 digit resolution highest accuracy of 50 ppm for ratio and phase low weight remote control and data transfer via RS232 interface Technical Data

BR-I / U

BR-I / U

Burden Artificial load for voltage and current transformers Electronically compensated current and potential burden according IEC 60044 and ANSI/IEEE C57.13 standards high precision by compensating uncertainties of the passive burden elements electronically wide range of rated voltages / currents and powers any burden value up to 200 VA add on burdens up to 1’000 VA remote control via RS232 interface Technical Data Current Burden Technical Data Voltage Burden  

Winding Testers for large electrical machines

Winding Testers for large electrical machines

The Presco winding testers have been specifically designed as impulse test systems for diagnosis of windings and coils of large electrical machines in the MW-and MVA-range according to the international standard IEC 60034-15 (“Rotating electrical machines. Part 15: Impulse voltage withstand levels of rotating electrical a.c. machines with form wound stator coils”). Demand for our new line of impulse test systems arose from the fact, that our customers required a performance level of impulse withstand testing that was difficult to obtain with commercially available products.   Unlike other commercial products, the Presco impulse test systems provide a real resonant circuit between the inductive test object and the built-in energy storage capacitor with the oscillating current flowing between the test object and the built-in capacitor for the entire duration of the damped oscillations. Thus the sensitivity of the measurement is greatly enhanced. Furthermore the front time of the generated impulse tf= 0.2μs (+0.3μs / -0.1μs) complies with the IEC 60034-15 specifications. Our easy-to-use impulse test systems are designed using state of the art technology and excel with their high-energy discharge capability as well as their ruggedness, reliability and longevity in harsh environments. Our impulse test systems are available as stationary units for voltages up to 15 kV and mobile units up to 6 kV, both being equipped with all the safety measures common to professional high voltage test equipment. Impulse test systems with higher voltage outputs will be available in the near future as replacements of old Haefely WP-series. The capabilities of the systems can be expanded with AC- or DC-voltage testing features at request. MOCOTE Mobile coil tester for on site measurements on large electrical machines  Mobile coil tester specifically designed for on site measurements on large electrical machines (e.g. rotor poles of large synchronous machines) Rugged design for reliable…

High Voltage capacitors

High Voltage capacitors

We supply capacitors for nearly any application, such as oil-paper capacitors for partial discharge applications or as voltage divider, highest accuracy air capacitors as reference for capacitance and tand measurements or metrology purposes. Solid State Standard Capacitors for capacitance and tand measurements e.g. on transformers or rotating machines as well as compressed gas standard capacitors for high accuracy measurements from 25 kV up to the highest voltages.     Coupling Capacitors Partial discharge coupling capacitors with nominal voltages up to 200kV Standard Air Capacitors High precision air capacitor for capacitance and tan delta measurement Solid State Standard Cap. Solid state standard capacitor with nominal voltages up to 100kV Compressed Gas Cap. Highest accuracy up to the highest voltages    

CC – Series

CC – Series

Partial discharge coupling capacitors with voltage range from 20kV up to 100kV range from 1nF to 10nF voltage range from 20kV up to 100kV PD level at nominal voltage < 1pC built in over voltage protection Extra Information Datasheet CC-001N-0030 Datasheet CC-001N-0050 Datasheet CC-001N-0100 Front – Hi-Res (290kB)  

CL – Series

CL – Series

2kV standard air capacitors for high precision tan delta and voltage measurement values 100pF, 1000pF, 10’000pF very low temperature and aging coefficient very low voltage dependency loss factor lower than 1E-5 Extra Information Datasheet CL-00N1-0002 Datasheet CL-001N-0002 Datasheet CL-010N-0002