1.
2.
3.
Application
Manage sound and vibration
Gas pulsation
The Danfoss CH scroll compressors have been designed and tested to ensure that gas pulsation has been optimised
for the most commonly encountered air conditioning pressure ratio. On heat pump installations and other
installations where the pressure ratio lies beyond the typical range, testing should be conducted under all expected
conditions and operating configurations to ensure that minimum gas pulsation is present. If an unacceptable level is
identified, a discharge muffler with the appropriate resonant volume and mass should be installed. This information
can be obtained from the component manufacturer.
Mitigation Methods
To ensure minimum vibrations transmission to the structure, strictly follow Danfoss mounting requirements
(mounting feet, rails etc..). For further information on mounting requirements, please refer to section Design
compressor mounting.
Ensure that there is no direct contact (without insulation) between vibrating components and structure.
To avoid resonance phenomenon, pipings and frame must have natural frequencies as far as possible from
running frequencies(50 Hz). Solutions to change natural frequencies are to work on structure stiffness and mass
(brackets, metal sheet thickness or shape…)
Manage Operating envelope
Compressor ambient temperature
CH compressors can be applied from -35°C to 51°C ambient temperature. The compressors are designed as 100 %
suction gas cooled without need for additional fan cooling. Ambient temperature has very little effect on the
compressor performance.
High ambient temperature
In case of enclosed fitting and high ambient temperature it’s recommend to check the temperature of power wires
and conformity to their insulation specification. In case of safe tripping by the internal compressor overload
protection the compressor must cool down to about 60°C before the overload will reset. A high ambient
temperature can strongly delay this cool-down process.
Low ambient temperature
Although the compressor itself can withstand low ambient temperature, the system may require specific design
features to ensure safe and reliable operation. See section ‘Specific application recommendations’.
Operating conditions
The scroll compressor application range is influenced by several parameters which need to be monitored for a safe
and reliable operation.
These parameters and the main recommendations for good practice and safety devices are explained hereunder.
•
Refrigerant and lubricants
•
Motor supply
•
Compressor ambient temperature
•
Application envelope
(evaporating temperature, condensing temperature, return gas temperature)
Motor supply
CH scroll compressors can be operated at nominal voltages as indicated section “Motor voltage”. Under-voltage and
over-voltage operation is allowed within the indicated voltage ranges. In case of risk of under-voltage operation,
special attention must be paid to current draw.
Scroll compressors, CH290 and CH485 | Application
© Danfoss | Climate Solutions | 2022.09
AB236986442743en-000501 | 28