Articles
Practical guides on testing protection relays, instrument transformers and power systems, from the engineers who build the testers.
November 8, 2026 · 1 min read
How to Choose a Protection Relay Tester: 7 Things to Check
Relay testers look alike on a data sheet. These seven checks show which one fits the relays you really test, today and in five years.
Read the articleNovember 8, 2026 · 2 min read
How to Test an Overcurrent Relay: Pickup and Trip Time
An overcurrent relay has two things to prove: it picks up at the right current and it trips in the right time. Both are checked by secondary injection with a relay test set.
Read the articleNovember 8, 2026 · 2 min read
What Is a Protection Relay Tester and How Does It Work?
A protection relay watches the power system and trips a circuit breaker when something goes wrong. A protection relay tester is how you prove, before a real fault, that it will.
Read the articleFrequently asked questions
Short answers about Vebko relay testers, software and support.
What is a protection relay tester?
A protection relay tester is a test set that injects precise currents and voltages into a protection relay and checks how it responds, so you can confirm it will trip correctly when a fault happens on the power system.
Learn moreWhat can the Vebko AMT tester test?
The AMT105 and AMT205 test protection relays, circuit breakers, energy meters and transducers, current transformers (CT), capacitor voltage transformers (CVT) and power transformers. AMTPro software runs the tests and makes the reports. Which tests are available depends on the device and the software package.
Learn moreWhich software runs the AMT tester, and where do I download it?
The AMT tester is run by AMTPro on Windows. Every released version, with release notes and system requirements, is on the software page.
Learn moreWhat is the AMR relay?
The AMR is Vebko's modular protection relay for substations. You choose its power supply, CPU, input and output modules and front panel, and the relay configurator gives you the order code.
Learn moreWhere can I learn to use the tester and the relay?
Vebko publishes step-by-step training videos for the AMT tester, the AMR relay and each new software release, grouped by topic.
Learn moreHow do I get a calibration certificate for my device?
Type the device's serial number into the lookup on the certificates page to find and download its calibration certificates.
Learn moreHow can I buy a Vebko tester or find a local agent?
Ask for a quote on the sales page, or use the agents map to find the Vebko agent nearest to you for sales and support.
Learn more