Over Current & Earth Fault Trip Testing
Protection Relay Trip Testing for Safe HV & LV Operation
We provide specialist over current and earth fault trip testing for high voltage and low voltage systems across the UK. Our service ensures protection devices operate correctly and trip within designed limits to keep systems safe and compliant.
Why Protection Trip Testing Is Essential
Protection relays are designed to detect over current or earth faults and isolate supply to prevent damage, fire or injury. Routine testing verifies settings, timing and response to confirm protection systems are fully operational.
Our trip testing helps:
- Verify relay response times and coordination
- Ensure protection schemes match system load
- Prevent nuisance tripping or delayed faults
- Confirm new installations are safe before energisation
- Support compliance with safety and electrical standards
We test both standalone and integrated protection devices in substations, switchgear and control panels.
What We Test
Our engineers use calibrated secondary injection equipment to simulate fault conditions. We measure how quickly and accurately the protection device responds and confirm all logic, alarms and trips are functioning.
Trip testing covers:
- Over current protection relays
- Earth fault protection systems
- Time-current and IDMT settings
- Relay logic and output functions
- Tripping of breakers and contactors
- Settings validation and backup protection
Every test is recorded with time, values and outcomes, followed by a formal commissioning report.
Suitable for
- Commercial and industrial switchgear
- Substation installations
- Renewable and battery systems
- Private high and low voltage networks
Frequently Asked Questions
What is over current and earth fault trip testing?
It is the process of simulating fault conditions to check that protection relays and trip systems respond correctly and isolate faults safely.
How often should this testing be done?
Trip testing is typically carried out during initial commissioning and then as part of routine maintenance, usually every 1 to 3 years depending on system use.
Can you test different makes of relays?
Yes. We test a wide range of protection relays including digital, electromechanical and multifunction devices from all major manufacturers.
Will I receive a test report?
Yes. Every test includes a full report with response times, test values, verification of settings and any recommendations for adjustment.