CBB61 3.5uF 250VAC Ceiling Fan Motor Capacitor – 2 Wire (Brand New)

100% brand new CBB61 3.5µF (3.5mfd) AC motor capacitor, rated 250VAC 50/60Hz, ±5% tolerance. Metallized polypropylene film (MPP) dielectric in a flame-retardant rectangular plastic case with epoxy seal. 2-wire, non-polarized — direct replacement for weak or swollen ceiling-fan capacitors causing slow start, humming, or stuck speeds.

Specifications

Type	CBB61 metallized polypropylene film (MPP) motor run capacitor
Capacitance	3.5µF / 3.5mfd, ±5%
Voltage	250VAC
Frequency	50Hz / 60Hz
Leads	2 wires (~120mm typical), non-polarized
Case	Rectangular ABS/plastic, ~37×26×15mm (1.5×1.0×0.6in) typical
Dielectric	Self-healing metallized polypropylene film
Climatic Category	40/85/21 (typical)
Mounting	Snap / cable-tie in fan switch housing
Polarity	None — AC film capacitor

What It Does

In a single-phase ceiling-fan motor, the capacitor sits in series with the auxiliary winding and shifts current phase so the motor develops starting torque and holds steady speed. When the film degrades, µF drifts low, and the motor hums, lags, or won't self-start. Swapping in a fresh 3.5µF part restores rotation, speed response, and quiet running.[2,7,9](@ref)

Compatible Use Cases

• Ceiling fans (single-speed or switch-controlled)
• Wall fans, stand fans, table fans
• Exhaust / vent fans, range hood blowers
• Small single-phase AC motors, water pumps, generator exciter辅助
• Replacement for old 3.5µF 250VAC CBB61 / CBB60 film capacitors

Replacement Rules (don't guess)

• µF must match: 3.5µF, ±5% tolerance. Never "upgrade" to 4µF or 5µF blindly — wrong µF changes phase angle and can overheat the winding.
• VAC equal or higher: 250VAC → 370VAC/450VAC is fine. Never lower.
• Type: AC film (CBB61/CBB60), NOT aluminum electrolytic, NOT DC-rated cap.
• Wires: 2-wire single-value. If your fan had 3/4/5 wires, this part is wrong — order the multi-tap version.

Wiring (2-wire)

1. Kill power at the breaker. Confirm no voltage at the fan canopy.
2. Photo the old cap before pulling connectors.
3. CBB61 is non-polarized — either lead can go to either terminal. One lead lands on the motor auxiliary-winding wire (often brown/blue), the other on the line/neutral side per the fan diagram.[7,10](@ref)
4. Push spade/quick-connects fully home. No bare copper showing.
5. Restore power, test all speed settings, listen for hum.

Failure Symptoms Checklist

• Fan hums but won't start until blade is pushed by hand
• Runs noticeably slower than before
• Speed pull-chain does nothing or skips speeds
• Capacitor case swollen, discolored, or smells burnt
• Motor warm-to-hot during normal run

CBB61 vs CBB60 vs CBB65 (quick)

Type	Shape	Use
CBB61	Rectangular plastic	Ceiling/exhaust fans, small motors
CBB60	Cylindrical plastic	Pumps, washers, small compressors
CBB65	Metal can, oil-filled	HVAC compressors, continuous heavy duty

For a ceiling fan, CBB61 is the correct form factor. Don't over-spec a metal-can CBB65.[2](@ref)

Condition

100% brand new, lead-forming intact, case not bulged, capacitance within ±5% at outgoing test. RoHS-compliant, flame-retardant case.