36-15-5-3744 Rotom Dual Run Capacitor for HVAC Systems, Restores 15/5 MFD Motor Performance

Rotom 36-15-5-3744 is an oval dual motor-run capacitor rated 15/5 µF and 370/440 VAC.

The 15 µF HERM section supports the compressor circuit, while the 5 µF FAN section supports the condenser-fan motor. Both sections share the common C terminal.

A weak, swollen or electrically failed capacitor may contribute to a compressor or fan motor that hums, starts slowly, operates intermittently or does not start.

Confirm the original capacitor is rated exactly 15/5 µF. The replacement voltage rating must be equal to or higher than the original. Also verify the oval case dimensions and terminal arrangement before ordering.

This capacitor measures approximately 2.80 × 1.77 × 2.56 inches (71 × 45 × 65 mm).

Disconnect power before servicing HVAC equipment. Capacitors can retain an electrical charge after power is removed — testing and replacement should be performed using proper electrical-safety procedures by a qualified HVAC technician.

Is This the Right Part?

Fits applications requiring an oval 15/5 µF dual run capacitor rated at 370V or 440V, subject to dimensional and terminal verification. A 440V capacitor may replace a 370V capacitor with the same µF rating; a 370V-only capacitor must not replace a 440V-rated capacitor.

Common Symptoms

• Compressor hums but does not start, or starts very slowly
• Condenser fan motor does not start or runs intermittently
• Unit trips a breaker or overload protector on startup
• Capacitor case is visibly swollen, bulging or leaking
• System runs but with reduced cooling or heating performance

Check Before Replacing

• Test the capacitor with a capacitance meter — compare both HERM and FAN readings against the tolerance printed on the original label before condemning it.
• Confirm the original is a dual-section run capacitor rated exactly 15/5 µF — do not substitute a different µF rating even if the capacitor fits physically.
• Verify the original voltage rating — a 440V replacement is acceptable for a 370V application, but a 370V-only capacitor must not replace a 440V-rated application.
• Confirm the oval case dimensions (2.80 × 1.77 × 2.56 in) and three-terminal arrangement (C, FAN, HERM) match the original mounting space and wiring.

Part Details

Installation Notes

1. Disconnect and lock out power to the HVAC equipment before servicing.
2. Safely discharge the original capacitor before touching any terminals — capacitors retain charge after power is removed.
3. Photograph the original wiring — note which wire connects to C, FAN and HERM terminals.
4. Compare the new capacitor with the original — confirm both µF values, voltage, case shape, dimensions and terminal positions.
5. After installation, restore power and test both the compressor and condenser fan for correct starting and running behaviour.

Use a qualified HVAC or electrical technician when diagnosis or installation is outside your experience.

Verified Compatible Applications

This capacitor is selected by electrical and dimensional specifications, not by equipment model number. It is suitable for compatible applications requiring an oval dual-section 15/5 µF run capacitor rated 370V or 440V.

Fitment reminder: Match both capacitance values (exactly 15 µF HERM and 5 µF FAN), voltage (370V or 440V), capacitor type (dual-section run), case shape (oval), terminal arrangement (C, FAN, HERM) and available mounting space before ordering.