MV Switchgear
Maintenance, testing and commissioning of medium-voltage (MV) switchgear, with a test programme agreed for the equipment and the purpose of the work.
Typical situations
- New MV switchgear needs testing and commissioning before energisation.
- Existing switchgear is due for planned maintenance.
- Protection relays need testing after installation, replacement or setting changes.
- Interlocks or trip circuits are not operating as expected.
What we do
- Planned maintenance and circuit-breaker service.
- Protection-relay testing by secondary injection.
- Circuit-breaker timing and contact-resistance measurement.
- Interlock, trip-circuit and functional checks.
- Commissioning support for new or modified switchgear.
Confirmed after survey or agreed separately
- Secondary injection verifies relay response to injected signals; it does not replace primary injection, insulation or other tests where they are required.
- The test list and acceptance criteria are agreed per equipment, with reference to manufacturer guidance.
- Switching operations and permits to work remain under the control of the site's authorised persons.
- A protection coordination study — fault levels, settings calculation and grading — is a separate scope and is confirmed when needed.
Engineering interfaces
- Transformers and LV distribution
- Utility incomers and metering
- Protection relays, CTs and VTs
- Generator and transfer control schemes
Typical deliverables, as agreed
- Test records with results against agreed criteria
- Record of relay settings as tested
- Findings and recommendations
Frequently asked questions
Do you calculate protection settings?
Relay testing verifies that the applied settings operate as intended. Calculating settings and grading requires a protection coordination study, which is quoted separately when needed.
What should we send for a quotation?
Switchgear manufacturer and type, number of panels, relay models, the reason for the work (new installation, maintenance or fault) and any outage windows.