Description
Megger BM25 Insulation Tester Repair
The BM25 is a legacy 5 kV insulation resistance tester — a rugged, long-serving instrument still found across utilities and industrial plants for high-voltage insulation testing. As older HV equipment, the faults are aging faults: the high-voltage generator and the range/measurement circuitry showing years of field service.
June Company repairs and calibrates the BM25 for crews keeping a proven legacy Megger in service.
Common BM25 problems we fix
- Won’t reach test voltage — HV generator aging on a long-serving unit, repaired so it delivers full rated output again.
- Erratic or drifting readings — measurement-circuit aging, recalibrated for stable insulation-resistance values.
- Range selector intermittent — rotary-switch contact wear, a common legacy fault, cleaned or replaced.
- Guard terminal faults — guard-circuit damage.
- Won’t power up reliably — power and connector faults from age.
FAQs
It’s an old BM25 — still worth fixing? Yes. These are rugged instruments with plenty of life left; a repair keeps it in service for far less than replacement.
Can you calibrate and certify it? Yes — recalibrated against our reference standards with a NIST-traceable certificate.
Every repair includes NIST-traceable calibration and a 90-day parts-and-labor warranty. Email us or submit a service request.







