Description
Fluke 1550C Insulation Tester Repair
The Fluke 1550C is a 5 kV insulation resistance tester (megohmmeter) — it applies selectable DC test voltages up to 5 kV and measures very high insulation resistance with diagnostic tests (PI/DAR and step-voltage) for motors, cables, and high-voltage apparatus. The hardworking part is the high-voltage generator, so that’s where most faults originate.
FlukeMeterRepair.com repairs and calibrates the Fluke 1550C for motor shops and electrical maintenance crews.
Common Fluke 1550C problems we fix
- HV generator faults — won’t reach the selected test voltage or output is low, repaired so it hits full 5 kV.
- Step-voltage / diagnostic faults — the step-voltage, PI, or DAR functions not running, restored.
- Measurement drift — insulation-resistance readings drifting, recalibrated against standards.
- Display, battery, or terminal faults — repaired.
- Won’t power on — power/battery faults.
FAQs
My 1550C won’t reach 5 kV — fixable? Yes. HV generator faults are the usual cause and they’re repairable, then verified so the tester delivers full rated voltage and your readings are valid, with a NIST-traceable certificate.
Are the diagnostics verified? Yes — step-voltage, PI, and DAR are checked along with recalibration.
Every repair includes NIST-traceable calibration and a 90-day parts-and-labor warranty. Email us or request service.






Ted White –
Our Fluke insulation tester completely died, and I mean died. We could not charge the tester and when we did it smoked. We assumed either the battery, electronics boards, or power supply.