| S.No. | Checkpoint | IS Requirement | Status |
|---|---|---|---|
| A. TEST PROCEDURE & SETUP | |||
| A1 | Circuit isolated and disconnected from supply before testing; main switch in OFF position Acceptance: Circuit isolated, supply switch OFF, confirmation obtained from site engineer | Cl. 11.1.1 — Safety precaution | OK NC NA HOLD |
| A2 | Megohmmeter (megger) is calibrated; test voltage is 500 V DC for LV circuits (≤1000 V) Acceptance: Megger rated 500 V DC for LV, calibration certificate dated within 12 months | Cl. 11.1.2 — Equipment specification | OK NC NA HOLD |
| A3 | All load equipment (luminaires, sockets, switches) disconnected or isolated during testing Acceptance: All load equipment isolated, connections verified OFF, MCBs in OFF position | Cl. 11.1.3 — Load isolation | OK NC NA HOLD |
| A4 | Test is performed in dry conditions; equipment is at ambient temperature (±5°C variation acceptable) Acceptance: Ambient temperature recorded, no active heating/cooling, humidity ≤ 95% RH | Cl. 11.1.4 — Environmental conditions | OK NC NA HOLD |
| B. INSULATION RESISTANCE TESTING | |||
| B1 | Phase-to-Neutral insulation resistance measured; reading ≥ 1.0 MΩ minimum Acceptance: Reading ≥ 1.0 MΩ at 500 V DC, stable reading taken after 1 minute, recorded in report | Cl. 11.1.5 — Phase-neutral insulation | OK NC NA HOLD |
| B2 | Phase-to-Earth insulation resistance measured; reading ≥ 1.0 MΩ minimum Acceptance: Reading ≥ 1.0 MΩ at 500 V DC, stable reading after 1 minute, recorded in report | Cl. 11.1.6 — Phase-earth insulation | OK NC NA HOLD |
| B3 | Neutral-to-Earth insulation resistance measured; reading ≥ 1.0 MΩ minimum Acceptance: Reading ≥ 1.0 MΩ at 500 V DC, stable reading after 1 minute, recorded in report | Cl. 11.1.7 — Neutral-earth insulation | OK NC NA HOLD |
| B4 | Three-phase system: Phase A-to-Phase B, Phase B-to-Phase C, Phase C-to-Phase A insulation tested; all ≥ 1.0 MΩ Acceptance: All inter-phase readings ≥ 1.0 MΩ, stable after 1 minute, recorded individually for each phase pair | Cl. 11.1.8 — Inter-phase insulation | OK NC NA HOLD |
| B5 | If insulation reading is marginal (0.5-1.0 MΩ), circuit is left isolated and rechecked after 24 hours (moisture drying) Acceptance: Marginal readings (0.5-1.0 MΩ) isolated, dried with heat if necessary, re-tested after 24 hours or after heating | Cl. 11.1.9 — Low resistance procedure | OK NC NA HOLD |
| C. ACCEPTANCE CRITERIA & REMEDIAL ACTION | |||
| C1 | All readings ≥ 1.0 MΩ: Circuit APPROVED for energization; test certificate signed Acceptance: All insulation readings ≥ 1.0 MΩ, circuit approved, test report signed and filed | Cl. 11.2.1 — Acceptance condition | OK NC NA HOLD |
| C2 | Reading < 0.5 MΩ: Circuit REJECTED; NCR raised, cable tested for fault location Acceptance: If < 0.5 MΩ: Circuit rejected, NCR raised, fault location testing performed, cable replaced if defect confirmed | Cl. 11.2.2 — Rejection condition | OK NC NA HOLD |
| C3 | Faulty section identified (if possible) and isolated; replacement cable laid and re-tested before approval Acceptance: Faulty cable section cut out, replacement cable installed, insulation re-tested and confirmed ≥ 1.0 MΩ | Cl. 11.2.3 — Repair procedure | OK NC NA HOLD |
| C4 | For marginal readings after drying, circuit may be approved WITH CONDITIONS pending final energization test Acceptance: After 24 h drying, reading ≥ 0.5 MΩ: approved with condition to monitor during first 48 hours of operation | Cl. 11.2.4 — Conditional approval | OK NC NA HOLD |