Testing & certificates
Every unit is tested, and you get the numbers
A refurbished breaker without a test record is an opinion. Ours leave with results for every protection element, every pole and every coil, printed against the limits they had to meet.
- Trip unitsSecondary injection
- ContactsResistance at 10 A
- Insulation500 V, every pole
- RecordsPhotos + parts list
Real examples
Two certificates from the workshop
Real test sheets from recent jobs, published with the customer's details, references and serial numbers removed. This is exactly what comes back with your unit.
Air circuit breaker certificate
Major service after corrosion, a broken charging handle and a missing CLOSE button. PR122/P tested at six points, all three poles.
See the certificate
Contactor certificate
Severe arc damage on one pole carrier. Contacts repaired and dressed across all three poles, coil proved at 85% voltage.
See the certificateOn an air circuit breaker
- Secondary injection of the trip unit with the manufacturer's test kit where one exists, at multiple points on each curve: long-time at 1.5× and 3×, short-time, short-time definite at high multiples, and instantaneous either side of its pick-up
- Each trip time recorded per pole, beside the tolerance band it had to fall in
- Contact resistance per pole at 10 A, in micro-ohms
- Insulation resistance at 500 V: phase to earth, phase to phase and across the open poles
- Closing coil, shunt trip, undervoltage release, motor operator and auxiliary contacts proved at their rated voltage
- Mechanical checks: contact wear, arcing contact gap, operation counter, interlocks, racking positions
- Over 30 mechanical service operations before sign-off
On a contactor
- Coil resistance and coil insulation to earth
- Pick-up and drop-out voltage measured
- Operation at 85% of rated coil voltage
- Main contact resistance closed, per pole
- Insulation resistance phase to earth and phase to phase
- Auxiliary contacts checked open and closed
- 30 electrical and 30 mechanical operations
Primary or secondary injection?
Secondary injection tests the trip unit's electronics and the breaker's response by injecting a signal into the trip unit. Primary injection pushes real current through the poles and sensors. We use secondary injection as standard, as the sample certificates show. Tell us if your specification calls for primary injection and we will advise.
Testing questions
Can you test to our settings?
Yes. Send your settings or coordination study values and we'll set and test the trip unit to them. Otherwise we test at the as-found settings and record them on the certificate.
Do you test the trip unit or the whole breaker?
Both. The injection test proves the trip unit measures and times correctly and that the breaker actually opens. Contact and insulation resistance, coils and the mechanism are tested on the breaker itself.
What test equipment do you use?
The manufacturer's own test kit where one exists, such as ABB's Ekip test kit used on the sample Emax certificate, plus low-resistance ohmmeters and insulation testers for the contact and insulation tests.
Can you complete our own QA form?
Yes. Send it with the order and we'll fill it in alongside our certificate.
Send us the nameplate
A photo of the nameplate and the fault is enough for a first answer. We reply the same working day with a recommendation and a price for diagnosis and freight.