Biblioteca Técnica

This application note is more than a description of how to use SVERKER 900 for testing frequency relays. It also wantsto spread the knowledge about IEC standardization in relay protection. Many engineers often associate theIEC series of protection standards IEC 60255-1xx1to relay type testing, and believe that they do not need to have competence about this series of standards. This is a misunderstanding: many of the concepts, definitions and test procedures described in thestandards are there to be used in relay technique, no matter if the role is relay manufacturer, user, or commissioning / maintenance testing engineer ([2], [3]).

When measuring very low resistance the four-wire test method has for many years been the standard method. The main advantage being that it simply and easily removes the resistance of the test leads from the measurement. However, what happens when those test leads need to be verylong?

Introducing the first low resistance ohmmeter to feature a difference meter, a device that turns changes in resistance into a moving pointer and percentage change. When testing multiple similar connections, it makes it easy to spot those small increases in resistance that eventually turn into major faults.

Safety warnings for DLRO2

Completing turns ratio tests on all transformer taps can be a cumbersome process. With One Touch OLTC from the TTRU3, anyone can configure and test all taps within a few short minutes.

When performing calibration verification of the TTRU3, the following factors need to be considered to achieve accurate measurements and prevent damage to your calibration fixture or TTRU3.

Not all product demonstrations go as planned. Unforeseen problems can arise, causing the demonstration to go awry. We can either accept this as a failure or use it to create an opportunity. 

REQUIREMENTS FOR SAFE WORK ENVIRONMENT WHEN PERFORMING MV or LV POWER CABLE FAULT LOCATING BY DISCHARGING A HIGH VOLTAGE CAPACITOR.

Since the 1950’s vacuum has been used as insulation media in switchgears. Even though that technology has proven to be very reliable, over time air will leak into the vacuum chamber and degrade the insulation. Also, a good practice is to measure after transport or accidents. The accepted way to test the vacuum integrity has always been through a voltage withstand test. For field tests DC test is preferred due to the weight andsize of the instruments.

The is capable of performing turns ratio tests on any phase shifting transformer by allow-ing for phase shifts to be entered with respect to the secondary winding. But with all of the differ-ent ways phase shift is expressed, how do you know if the entered phase shift value is correct?