Primary & Secondary Injection Testing Service
Professional Injection Testing for HV and LV Protection Systems
We provide full primary and secondary injection testing services across the UK. Our testing ensures circuit breakers, relays and protection devices operate safely and accurately when faults occur.
What Is Injection Testing?
Injection testing simulates fault conditions by sending controlled current or voltage into the system. This verifies the correct function and response of protection devices under real-time scenarios.
We offer:
- Primary current injection for circuit breakers
- Secondary injection for relays and logic schemes
- Time-current curve verification
- Relay setting validation
- Tripping and output response checks
All tests are performed using calibrated injection test equipment by trained engineers.
Applications
Injection testing is essential for both new installations and ongoing maintenance. We support a wide range of industries including energy, utilities, commercial and industrial sectors.
Ideal for:
- Switchgear protection schemes
- Relay and CT/VT systems
- LV and HV circuit breakers
- Generator and transformer protection
- Safety-critical equipment
We provide detailed reports confirming settings, accuracy and trip timing.
Frequently Asked Questions
What is the difference between primary and secondary injection?
Primary tests current through the full path including CTs and breakers. Secondary tests the relay logic using simulated signals without high current.
When is injection testing required?
It’s used during commissioning, after changes to protection settings, and during routine checks to ensure devices still operate correctly.
Do you test all relay types?
Yes. We work with digital and electromechanical relays from all major manufacturers.
Will we get a test report?
Yes. You’ll receive a full report with measured values, relay settings and confirmation that devices operate within expected limits.