Y-capacitor is a safety capacitor used in EMI filters to suppress common-mode interference by connecting between line/neutral and ground.
| Parameter | Typical range | Notes & selection driver |
|---|---|---|
| Capacitance Range | 1 nF – 47 nF | Common values: 1, 2.2, 4.7, 10, 22, 47 nF. Tolerance typically ±20% (M) or ±10% (K).IEC 60384-14 |
| Tolerance | ±10% or ±20% | Y-capacitors are not precision components; ±20% is common for Y2, ±10% for Y1.IEC 60384-14 |
| Safety Class | Y1 or Y2 class | Y1: rated AC 400V, peak 8kV impulse; Y2: rated AC 300V, peak 5kV impulse. Choose based on application.IEC 60384-14 |
| Rated Voltage | 250 VAC or 400 VAC | Y2 typically 250VAC, Y1 typically 400VAC. Must be rated for continuous AC line-to-ground use.IEC 60384-14 |
| Temperature Range | -40°C to +85°C (or +105°C for some) °C | Operating ambient temperature. Derating may apply above 85°C.IEC 60384-14 |
| Dielectric Strength | Y1: 4000 VAC for 60s; Y2: 1500 VAC for 60s VAC | Test voltage between terminals and case/ground. Higher for Y1 due to higher impulse rating.IEC 60384-14 |
| Insulation Resistance | ≥ 10,000 MΩ (at 25°C, 100 VDC) MΩ | Measured between terminals and case after 1 minute. Minimum value for safety.IEC 60384-14 |
| Lead Material | Tinned copper or copper-clad steel material | Leads must be solderable and corrosion-resistant. Diameter typically 0.6–0.8 mm. |
| Case Material | Flame-retardant plastic, UL94 V-0 rating | Epoxy resin encapsulation or plastic case. Must be flame-retardant to prevent fire spread.UL 94 |
| Dielectric Material | Metallized polypropylene (PP) or polyester (PET) material | Self-healing properties. PP for higher stability, PET for higher capacitance density. |
| Capacitance Drift | ≤ 5% after 1000 hours at rated voltage and upper temperature % | Long-term stability under load. Check datasheet for specific test conditions.IEC 60384-14 |
| Dissipation Factor | ≤ 0.1% at 1 kHz, 25°C % | Low DF indicates low losses. For PP typically <0.1%, PET <1%.IEC 60384-14 |
| Ambient temperature | -40°C to +85°C (up to +105°C for some) | Outside this window: Exceeding upper limit accelerates aging and may cause capacitance drift or dielectric breakdown. Below lower limit may cause cracking of encapsulation. |
| AC voltage (line-to-ground) | Up to rated voltage (250VAC for Y2, 400VAC for Y1) | Outside this window: Overvoltage can cause dielectric breakdown and short circuit, defeating safety function. |
| Impulse voltage (transient) | Y1: up to 8kV peak; Y2: up to 5kV peak | Outside this window: Higher transients can puncture dielectric, leading to short circuit and potential fire. |
| Frequency of AC supply | 50/60 Hz (standard) | Outside this window: Higher frequencies increase reactive current and heating; may exceed current rating. |
| Humidity | Up to 95% RH (non-condensing) | Outside this window: Condensation can cause surface tracking and insulation failure. |
Ranges are indicative industry figures for RFQ preparation, not a supplier commitment. Confirm every value and standard with the legal manufacturer before ordering.
This component is used in the following industrial products
A passive electronic component designed to suppress electromagnetic interference (EMI) in industrial electrical systems.
Electrical component that suppresses electromagnetic interference (EMI) and radio frequency interference (RFI) from power lines
An electrical component that filters and conditions the incoming AC power before it reaches the rectifier stage of an AC-DC converter.
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X-capacitors are connected between line and neutral (differential mode filtering) while Y-capacitors are connected between line/neutral and ground (common-mode filtering). Y-capacitors have stricter safety requirements due to their connection to ground.
Y-capacitors must meet stringent safety standards because they connect directly to ground. They are designed with reinforced insulation and self-healing properties to prevent electric shock hazards even if they fail.
These classifications indicate different safety levels based on rated impulse voltage: Y1 (8kV), Y2 (5kV), Y3 (n/a), Y4 (2.5kV). Higher numbers indicate higher safety requirements for different applications.
Editorial classification, named public sources where available, and source-reviewed manufacturer records. See the editorial policy.