Comprehensive Guide to Ceiling Fan Capacitors: Functions, Specifications, and Maintenance

Table of Contents

Understanding the Role and Selection of Ceiling Fan Capacitors
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A ceiling fan capacitor is a crucial electrical component designed to start and maintain the operation of ceiling fan motors. Its primary functions include:

Starting Assistance: At startup, the capacitor delivers extra current, helping the motor overcome initial static friction for a smoother start.
Speed Regulation: By adjusting the phase difference in the motor, the capacitor enables control over the fan’s speed.
Voltage Balancing: The capacitor helps balance the voltage across the motor terminals, ensuring stable and reliable operation.

Construction and Types
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Dielectric Material: Metallized Polypropylene or Polyester film
Winding: Non-inductive type
Protection: Epoxy resin filled
- BO type: Rectangular plastic case
- BL type: With mounting plates in case
- BT type: With mounting metal plates on top of case
- BR type: Round plastic case
Lead Styles:
- PC: PVC insulation wire
- FT: Fast-on terminals

Key Electrical Characteristics
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Parameter	Specification
Rated Capacitance (Cr)	1μF – 15μF (other tolerances available upon request)
Rated Voltage (RV)	160VAC – 550VAC
Capacitance Tolerance (at 1kHz)	±5% (J), ±10% (K), +10/-5% (U) (other tolerances available)
Operating Temperature Range	Min: -40℃, -25℃; Max: +70℃, +85℃
Withstand Voltage (at 25±5℃)	Between terminals: 1.75×RV for 10 sec; Between terminals and case: 2RV+1kV (2000V min.) for 1–60 sec
Insulation Resistance (Rins)	≥10³ MΩ·μF or τ≥1000s (τ=Cr×Rins)
Dissipation Factor (DF)	tan δ at 25±5℃, 1kHz: 0.1μF≤Cr≤1μF: 0.8% max; Cr>1μF: 1.0% max
Endurance Test	1.25RV continuous at max temp; Capacitance change (ΔC/C): ≤±3%
Damp-heat Test	40±2℃, 90–95% RH, 1000±24h; Capacitance change (ΔC/C): ≤±0.5%

Application Scenarios
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Ceiling fan capacitors are primarily used to start and run ceiling fan motors. Their main applications include:

Start Capacitor: Provides the necessary torque for the motor to begin spinning by being placed in series with the starting winding.
Run Capacitor: Connected in series with the main winding to maintain stable current and speed during operation, enhancing efficiency and smoothness.
Speed-Adjusting Capacitors: In multi-speed fans, different capacitors are used to vary voltage and current, enabling speed control.

Ceiling fan capacitor application diagram

Maintenance and Replacement Tips
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Inspection: If your ceiling fan struggles to start or runs at inconsistent speeds, the capacitor may be faulty. Use a capacitance tester to verify if the value is within the normal range.
Replacement: Damaged capacitors should be replaced with new ones matching the original capacity and voltage rating.
Compatibility: Always select capacitors compatible with your fan motor to prevent potential damage. Refer to your fan’s manual or consult a professional for guidance.

Purchasing Guidelines
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Capacity and Voltage: Choose based on your fan’s design and power requirements. Typical voltage ratings range from 250V to 450V.
Operating Temperature: Ensure the capacitor can operate reliably in your environment, especially in high-temperature conditions.

Retail and Ordering Information
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Pricing: Prices vary depending on specifications (capacitance, voltage) and order quantity. Bulk purchases often receive discounts, while retail prices may be slightly higher.
Availability: Delivery times depend on stock. Some specifications may require longer lead times.
Minimum Order Quantity (MOQ): Some suppliers may require a minimum order, especially for higher-value capacitors.
Payment Methods:
- Domestic (Taiwan): Bank transfer and cash accepted.
- International: PayPal only. Production begins after payment confirmation.
Shipping: Charges vary by weight, location, and delivery speed. Tracking numbers are provided upon dispatch.
Return Policy: Opened retail products cannot be returned due to their specialized nature.