EN
LVD Leakage Voltage Test
LVD leakage voltage test: touch current measurement on live equipment against standard limits, reported by authorised engineers.
The LVD leakage (touch current) test measures the currents flowing from live equipment to earth and non-conductive metal surfaces using the standard measurement device (network impedance), comparing them with acceptance limits. While insulation and hipot tests verify the de-energised condition, the leakage test measures behaviour in real operating conditions (mains energised, running) — the direct counterpart of human contact. On filtered, EMC-capacitance bearing drive units, leakage currents normal by design can reach dangerous levels through insulation failure or wrong earthing.
Measurement Scenarios
- Earthed (normal) leakage: Current from the external metal to earth with the protective conductor connected; measured on each L-N and L/N-E combination. The natural filter-capacitive current is noted on RCD circuits.
- Open earth (single fault) leakage: With the protective conductor disconnected, whether the touch current still stays within the safe band is researched — the real risk scenario in a fault state.
- Multi-phase circuit: The worst step is found with neutral open and phase rotation changed; main and auxiliary circuits evaluated separately on multi-motor units.
- Limits: Practically 3.5 mA (earthed) and 0.7 mA (handheld gripped metal) approaches serve the warning thresholds; firm acceptance is the manufacturer, TS EN 60204-1/IEC 62353 and product standard value. Ambient humidity-temperature are recorded.
Interpretation
High leakage has three root causes: insulation degradation (moisture-contamination-wear), capacitive leakage (EMC filter, long cable — "normal" but affecting RCD selectivity) and wrong connection (neutral-earth bridge, PE joined to foreign earth). Separation combines the measurement with insulation test, earth continuity and RCD function: high leakage with low insulation resistance shows real degradation; high leakage with sound insulation shows capacitive flow. Leakage approaching the RCD's tripping value produces false alarms or delayed tripping, so threshold analysis per circuit is made.
Legislation and Outcome
The test is within periodic electrical inspection under 2014/35/EU LVD, Law No. 6331, the Internal Electrical Installations and Work Equipment Regulations. References: IEC 62353 / TS EN 62353, IEC 60990 (touch current methodology) and TS EN 60204-1. The protocol is reported signed with circuit diagram, step values, trip analysis and proposals; over-limit cases plan insulation repair, earthing correction or RCD capacity revision. Leakage tests are in our PL Analysis and LVD Tests set; see the complementary Insulation Test and RCD Test, or contact us for a programme. The protocol also carries the instrument serial and calibration number, making the result metrologically traceable and audit-proof.
FAQ on LVD Leakage Voltage Test
While the device is energised-working, it measures how much current escaping through insulation weakness-emission leaks outward over the body-earth-touch path. The measurement is made in mA with the standard network imitating the resistance-capacitance behaviour of the human body (IEC 60990 / VDE 0701-0702 person simulation); under both normal and single-fault (RCD-dropped) conditions. The result is compared with the device-type (handheld-fixed-medical) limit table; it is the live-state safety layer completing the insulation-HV test.
The limit is typically in the 0,25-3,5 mA band by device class (class 0-I-II split; medical is tighter). The natural source of leakage is the EMI-filter-Y-capacitor emission (cheap capacitive) current; insulation-moisture-contamination and insulation defect add on top. High-dusty-hot service environment, long-cable supply, faulty resistor-compressor matter. Above limit: leak-source isolation verification; the RCD-earthing (broken PE-open neutral) effect is investigated separately.
The danger of leakage depends on its escape path: on a class with sound PE the leak returns safely to earth; with PE broken, body voltage becomes touch current. Therefore continuity measurement comes first; earth resistance (earthing control) and RCD (RCD inspection) complete the package. RCD-current-threshold-cord compatibility: a high-leakage device group needs a threshold setting that will not nuisance-trip; excessive leakage produces continuous-trip fatigue.
Leakage testing becomes routine on hand-tool job sites (construction-tenant-periodic inspection regulation practice) and critical facility tools; manufacturer series test (similar to IEC 62353) and facility periodic control (yearly) are two tiers. Measurement uses a calibrated leakage analyzer (IEC 62353 compatible combined test device); reference-earth-grid-phase-neutral correct connection; result-limit-item-document-report-trend. A rising leakage slope is an early maintenance input as insulation-ageing-fault precursor.