Electrical Continuity Testing & Micro-Ohm Services in Pakistan.
TransfoLine delivers certified Electrical Continuity Testing and Digital Low-Resistance Ohmmeter (DLRO / Ductor) Measurements across Pakistan. Using calibrated 4-wire Kelvin test instruments from Megger and Fluke, we measure micro-ohm resistance across copper busbar joints, protective grounding bonds, and switchgear frames to prevent overheating and shock hazards.
What is Electrical Continuity Testing?
Continuity testing is the precision measurement of low electrical resistance across conducting paths, protective bonding conductors, and metallic joints. By injecting a high DC test current (10A to 100A) using the 4-wire Kelvin bridge method, our engineers detect micro-resistance anomalies that cause catastrophic thermal runaway under full operating load.
Busbar Splice Micro-Ohm Verification
Measures resistance across overlapping copper/aluminum busbar joints. Guarantees that joint resistance is equal to or lower than the adjacent solid copper conductor to prevent contact burning.
Protective Bonding Continuity
Verifies low-resistance bonds (≤ 0.1Ω) between equipment metallic enclosures, cable trays, structural steel, and the main earthing terminal to ensure instantaneous breaker tripping during ground faults.
Continuity & Micro-Ohm Testing Applications
Standard Resistance Thresholds for Continuity & Bonding
| Test Connection Type | Testing Instrument | Standard Limit | Governing Standard |
|---|---|---|---|
| HT / LT Busbar Bolted Joints | Megger DLRO (10A–100A DC) | ≤ 20 – 35 μΩ | NETA ATS Sec 7.4 |
| Protective Equipotential Bonding | Low Resistance Ohmmeter (200mA) | ≤ 0.05 – 0.10 Ω | IEC 60364-6 / BS 7671 |
| Circuit Breaker Main Contacts | 100A DC Micro-Ohmmeter | ≤ 30 – 50 μΩ | IEC 62271-100 |
| Lightning Protection Down-Conductors | 4-Terminal Micro-Ohmmeter | ≤ 0.20 Ω (End-to-End) | IEC 62305-3 |
Frequently Asked Questions.
Expert guidance on low resistance micro-ohm testing.
DEFECTS What happens if a busbar joint shows high micro-ohm resistance?
High resistance indicates surface oxidation, inadequate bolt torque, or poor contact surface mating. We unbolt the joint, wire-brush contact surfaces, apply conductive anti-oxidation grease, and re-torque with calibrated torque wrenches before re-testing.
INSTRUMENTS Which micro-ohmmeters does TransfoLine use?
We utilize calibrated Megger DLRO10HD and Fluke 1587 high-precision low-resistance micro-ohmmeters capable of measuring down to 0.1 micro-ohms (μΩ) with four-wire Kelvin test leads.
Book Continuity & Micro-Ohm Testing.
Our testing engineers deploy nationwide across Pakistan with calibrated micro-ohmmeters.
Need busbar ductor testing, earth bonding verification, or plant-wide continuity testing? Contact us directly.