Danfoss 120Z0388 Heater

The Danfoss 120Z0388 Surface Sump Heater is a critical component for maintaining oil temperature in HVACR refrigeration compressors during off-cycles. Operating at 24V AC/DC with an 80W power rating, this crankcase heater prevents refrigerant migration and subsequent slugging during startup. Specifically engineered for compatibility with Danfoss SM, SY, and SZ series scroll compressors, this surface-mounted heater ensures that the lubricant remains at a lower viscosity and higher temperature than the rest of the system. This compressor oil heating solution is essential for low ambient temperature operations where cold starts could lead to mechanical failure. Each unit is designed for direct surface contact to maximize thermal transfer efficiency, ensuring that the sump temperature stays within the manufacturer's specified operational range to protect the compressor bearings and internal mechanical assemblies.

• Optimized Oil Chemistry: Maintains consistent oil-refrigerant separation to prevent foam-over during compressor ignition.
• Precise Voltage Integration: Designed for 24V control circuits, allowing for seamless integration without requiring additional transformers in most commercial cabinets.
• Reliable Heat Transfer: The 80W surface element provides concentrated heat directly to the sump housing for efficient thermal conduction.
• System Longevity: Reduces mechanical stress associated with liquid refrigerant dilution in the oil reservoir.
• Field-Ready Installation: Engineered for specific Danfoss scroll compressor footprints, ensuring a secure fit and maximum surface area contact.

Which compressor models are compatible with the Danfoss 120Z0388?
This surface sump heater is primarily used with Danfoss Maneurop and Large Scroll series compressors, including the SY240, SY300, and SZ240 SZ300 models requiring 24V power.

Does this heater require a thermostat for operation?
Standard field practice involves wiring the crankcase heater through the Normally Closed (NC) contacts of the compressor contactor so it energizes only when the compressor is idle.

What happens if the 80W heater fails in cold weather?
Failure to maintain sump heat leads to refrigerant condensing in the oil. Upon startup, this causes oil foaming, loss of lubrication to the scroll sets, and potential hydraulic lock.

Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.