Danfoss H-Series Scroll Compressors are 100% gas cooled & fitted with an automatic reset line break protector mounted internally on the motor windings.
The internal protectors respond to over-current, overheating & are designed to interrupt motor current under a variety of fault conditions such as failure to start, running overload & fan failure etc.
If the internal overload protector trips it must cool down to approximately +60 degrees Celsius to reset. (Depending on the ambient temperature this may take up to several hours)
Three Phase Sequence & Reverse Rotation Protection
The compressor will only operate properly with the correct rotation. If a three phase compressor is wired incorrectly it will run but will have excessive noise, no pressure differential between suction & discharge, plus the suction will become warmer rather than cooler.
The smaller range of Danfoss H-Series scroll compressors (up to HLP075) are able to run in reverse rotation safely for up to 150 hours without damaging the compressor, however phase monitors are still recommended.
The larger range of Danfoss H-Series scroll compressors (HLP078 onwards) should never be run in reverse. Danfoss recommends phase rotation protection should always be fitted to prevent these compressors from operating in reverse rotation.
Single Phase Compressors – Reverse Rotation
Brief power interruptions may cause reverse rotation of single phase scroll compressors. The internal protection will stop the compressor & once cooled down will restart with correct rotation.
Crankcase heaters are recommended on all stand-alone compressors & split systems. The heater should be energised for a minimum of 12 hours before initial start up (compressor service valves opened) & must remain energised whenever the compressor is off.
External High Pressure Switches are required for HCP094,109,120 scroll compressors as these models are not equipped with internal pressure relief valves.
Note: Crankcase heater is not supplied with compressor & should be purchased separately if required.