MiCOM Labs delivers dielectric strength testing, including dielectric withstand voltage verification, high-voltage insulation testing, and electrical safety compliance for connected products entering global markets.
Dielectric Strength testing applies controlled high voltage between primary circuits and grounding conductors to stress-test insulation barriers. The test reveals:
Trapped air pockets create breakdown paths. Contamination reduces dielectric strength. Insufficient material thickness allows current flow under overvoltage conditions.
Air gaps between conductors break down under voltage stress, creating arc paths during normal line overvoltages.
Component spacing violations introduce shock hazards. Improper grounding connections leave users unprotected. Inadequate creepage distances fail during manufacturing.
Dielectric strength test voltages are determined by insulation classification, working voltage range, and the governing standard, not just the nominal input voltage. Standards define required test levels for basic, supplementary, and reinforced insulation to ensure adequate protection against electric shock.
AC test voltages are typically specified as RMS values, while DC test voltages are derived by multiplying the AC value by approximately 1.414 (to convert to peak equivalent).
| Insulation Type | Typical Working Voltage Range | AC Dielectric Strength Test Voltage* | DC Dielectric Strength Test Voltage* |
|---|---|---|---|
| Basic Insulation | Up to 250V | 1,000–1,500V AC | 1,414–2,121V DC |
| Supplementary Insulation | Up to 250V | 1,500–2,000V AC | 2,121–2,828V DC |
| Reinforced Insulation | Up to 250V | 3,000–4,000V AC | 4,242–5,656V DC |
*Actual test voltages depend on the applicable standard (IEC 60601-1, IEC 61010-1, IEC 62368-1), pollution degree, overvoltage category, and specific device design.
Power distribution systems generate voltage spikes during normal operation. Inductive load switching off creates magnetic-field collapses that produce high-voltage impulses back into the line. Studies show that 120V systems experience peak overvoltages below 1,000V. Systems rated at 230V see overvoltages below 1,500V peak.
Dielectric strength testing at these elevated voltages confirms that the insulation can withstand normal transient events without breakdown.
MiCOM Labs integrates dielectric strength testing into comprehensive electrical safety evaluation programs. Our A2LA-accredited laboratory (ISO/IEC 17025) performs dielectric withstand testing in accordance with international standards.
Our automated systems ramp voltage at controlled rates. They hold at specified levels. They monitor for breakdown indicators, including current spikes.
Engineers track leakage current throughout the test cycle. Sudden, non-linear increases in signal indicate impending insulation failure before catastrophic breakdown occurs.
We test primary-to-ground paths. We test primary-to-secondary isolation. We verify accessible surface isolation.
The choice between AC and DC dielectric strength testing depends on product design and certification requirements.
| Test Type | Description | Key Advantage | Key Consideration |
|---|---|---|---|
| AC Dielectric Strength Testing | Applies alternating-polarity voltage stress, reversing the electric field direction 50–60 times per second to exercise insulation in both directions. | No capacitive charging delays; reaches full voltage faster than DC methods. | High capacitance products draw significant reactive current, which can mask true leakage unless in-phase and quadrature currents are isolated. |
| DC Dielectric Strength Testing | Applies a constant-polarity voltage with gradual ramping, allowing the capacitance to charge at each voltage step. | Clear measurement of leakage current; steady-state DC leakage reveals the true insulation resistance once the charging current decays. | Requires discharge time after testing; stored capacitive energy must dissipate before safe handling. |
Dielectric strength testing verifies that insulation systems can withstand elevated test voltages without electrical breakdown. The primary objective is to ensure no flashover, arcing, or insulation failure occurs during the test period.
| Criteria | Requirement |
|---|---|
| No Dielectric Breakdown | Insulation must withstand the applied test voltage without failure |
| No Flashover or Arcing | No visible or audible discharge across insulation barriers |
| Stable Current Response | Measured current remains stable and does not indicate insulation collapse |
| Test Duration | Voltage applied for the duration specified by the applicable standard (typically 1–60 seconds) |
| Standard Compliance | Test conditions and acceptance criteria defined by IEC 60601-1, IEC 61010-1, or IEC 62368-1 |
During testing, current is monitored only as an indicator of insulation integrity, not as a compliance limit. Sudden increases in current may indicate a breakdown, triggering the test system to shut down for safety.
Insulation breakdown occurs before the maximum current limit is reached. MiCOM Labs’ dielectric strength testers detect breakdown through multiple indicators:
High-frequency voltage variations signal electrical arcing. Current fluctuations persisting for more than 10 microseconds indicate insulation failure.
Internal air pockets break down in sequence, creating voltage plateaus during ramp-up.
Breakdown creates new conduction paths, causing abrupt current surges beyond normal capacitive charging rates.
Our test reports include all documentation required for certification submissions to regulatory authorities worldwide. Each dielectric strength test report contains:
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Reports reference applicable sections of IEC 61010-1 and IEC 62368-1. Our ISO/IEC 17025 accreditation ensures acceptance of test data by certification bodies in the US (FCC), Canada (ISED), the European Union (CE), the United Kingdom (UKCA), and Japan (MIC).
Certification authorities distinguish between type testing during product certification and production testing for ongoing manufacturing.
| Testing Type | When Performed | Test Duration | Voltage Levels | Test Coverage |
|---|---|---|---|---|
| Type Testing (Design Certification) | Once on representative samples during initial product certification | Extended duration (typically 60 seconds) | Higher voltage stress levels for double-insulated products | Multiple test points covering all insulation barriers |
| Production Testing (Manufacturing Line) | On every manufactured unit during production | Shorter duration (minimum 1 second) | Same voltage levels as type testing | Focused test points on primary insulation barriers |
MiCOM Labs supports both certification programs and production test development. We validate production test equipment. We establish appropriate test parameters. We provide operator training to ensure compliance with certification requirements throughout manufacturing.
Dielectric strength testing forms one component of a complete electrical safety evaluation. MiCOM Labs combines dielectric withstand testing with:
Megohm-level resistance measurements verify insulation quality under DC stress.
High-current testing confirms protective grounding connections meet resistance limits.
Operating voltage testing measures the actual current flow through body-impedance-simulation networks.
Our automated test sequences execute multiple safety tests in a programmed order, generating a combined test report that covers all safety requirements.
MiCOM Labs integrates dielectric strength testing into fast-tracked certification programs. Our automated testing platforms reduce test duration while improving accuracy.
For products requiring immediate market access in the US, Canada, EU, UK, or Japan, our direct certification authority enables the fastest possible approval timelines.
| Industry | Examples of Equipment |
|---|---|
| Medical Devices |
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| Healthcare Facilities |
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| Laboratory Equipment |
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| Home Healthcare Devices |
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