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OhmCert2026
Field Testing & Twin SaaS
🇬🇧 Full UI + PDF + National Standard Mapping: UI + PDF in English. Normative references follow international IEC 60364, BS 7671:2018+A2:2022, IEEE, and NFPA 70E/70B.
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#05Cable Insulation Resistance & Polarization Index Calculator

Project Framework (report reference): IEC 60364-4-41Applicable Standard: IEEE 43
Module Field Guides, Standard Selection & Tutorials (3)Browse All 93+ Guides →
1 · Field Measurement ProcedureHow to Measure & Test Insulation Resistance & PI on Site: Step-by-Step Field Procedure (IEEE 43)2 · Standards & Limit TablesWhich Standard Applies to Insulation Resistance & PI? Acceptance Limits, Annex Tables & Regional Equivalents (IEEE 43)3 · OhmCert Tutorial & Case StudyHow to Complete a Insulation Resistance & PI Certificate in OhmCert: Worked Case Study & Troubleshooting

Multi-Asset / Multi-Point Equipment Schedule

Inspect multiple transformers, panels, rooms, motors, or RCDs in this module without overwriting previous assets. Each item receives a permanent QR Sticker UID preserved across annual audits.

Sticker UID: OC-INSU-03D1
Plant & SLD (Auto-SLD)

Standard Limits, Equations & Space Presets

IEEE Std 43-2013 recommended DC test voltages, 40 degC temperature correction factor Kt, minimum insulation resistance R_min, and Polarization Index (PI) / Dielectric Absorption Ratio (DAR) criteria.

One-Click Normative Presets (Auto-fills Target Limits)

Measured Inputs

Calculated / Evaluated Results

PI = R10min / R1min evaluated to IEEE 43-2013 Table 3 (Class A minimum 1.5; Class B, F, H minimum 2.0; any class below 1.0 is a critical degradation alert). DAR = R60s / R30s follows industry field test convention (NETA MTS / Megger guidelines).

Pending / Not tested — results stay neutral until valid measured values are entered.

  • Polarization Index PI = R10min / R1min (Class B, F, H minimum 2.0)

    -

    Enter R1min and R10min to evaluate the polarization index.

    Pending

  • DAR = R60s / R30s - Dielectric Absorption Ratio (NETA MTS / Megger Guidelines)

    -

    Enter R30s and R1min (R60s) to evaluate DAR.

    Pending

  • IR Corrected to 40 degC (at T = 40.0 degC, V_test = 1,000 V)

    - MOhm

    R_40C = R_1min x 2^((T - 40)/10); >= 100 MOhm target for power cables / rotating machinery (IEEE 43-2013 §6.3 & §12.2).

    Pending

Verification Checklist (0 / 13)

Pending

  • 1Circuit / machine isolated, locked out (LOTO) and proven dead prior to HV DC injection [IEEE 43 §5]

  • 2Surge arresters, VFDs, electronic meters, and neutral earthing resistors disconnected before testing

  • 3Bushing and cable termination surfaces cleaned and dried to eliminate surface leakage current (Guard terminal used)

  • 4DC test voltage selected per IEEE Std 43 Table 1 (500V <1kV, 1000-2500V MV, 5000V >12kV)

  • 5Winding / conductor temperature and relative humidity (dew-point margin) recorded

  • 6Core-to-earth and phase-to-phase insulation resistance measured for all phase combinations

  • 71-minute IR reading corrected to 40 degC reference using IEEE 43 halving rule Kt = 0.5^((40-T)/10)

  • 810-minute Polarization Index (PI = R10/R1) and 60s/30s DAR recorded (or IEEE 43 §9.2 >5000 MOhm exemption noted)

  • 9Test object grounded for >= 4x test duration after completion to prevent capacitive return-voltage shock

  • 10Cable screen / metallic sheath and armour continuity and single/both-end earthing verified

  • 11Cable terminations, stress cones and boots inspected for corona tracking or partial discharge signs

  • 12Historical IR/PI trend compared against factory/commissioning baseline

  • 13Insulation tester calibration certificate verified and circuit safely restored

General Notes

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Free plan: 5 of 5 inspections / calculations left this month.