Cooling and fan operation, Operating voltage, Cooling and fan operation 10 – Lab.gruppen D Series 80:4L User Manual
Page 10: Low voltage country considerations

8. Cooling and fan operation
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D SERIES Lake Quick Start Guide rev 1.2.0
8. Cooling and fan operation
D Series devices use a forced-air cooling system with airflow from front to rear, allowing high continuous power 
levels without thermal problems. To facilitate maximum air flow, ensure that no objects such as rack doors or 
lids are placed at the front or rear of the rack. Never attempt to reverse the airflow. Make sure an adequate air 
supply is provided in front of the D Series device, and that the rear of the device has sufficient space to allow 
air to escape. It is recommended to keep the ambient temperature around the device as cool as possible. An 
increased temperature can have a significant negative impact on the expected lifetime on the components 
inside the D Series device. 
NOTE: Fit solid blanks (not ventilation blanks) to unused rack spaces to ensure effective air circulation. Leaving 
gaps in between items of equipment degrades the effectiveness of forced-air cooling. 
If installing one or more D Series devices in a rack with other fan-cooled equipment, confirm that all other 
equipment also uses front-to-rear airflow for cooling. If this precaution is not observed, there is a risk of 
overheating, as units with the reverse airflow will be drawing in air which has already been heated by the 
D Series devices.
The D Series device is equipped with a sophisticated temperature sensing system which protects it from any 
overheating which may occur as a result of inadequate ventilation.
9. Operating voltage
D Series has a universal power supply and its mains nominal and operating voltages are specified in the Technical 
Specifications (pages 26-27). D Series can be ordered with a variety of mains plugs. If the mains plug (AC plug) 
fitted to the mains cable (AC cord) is not appropriate for your country it can be removed and a locally-sourced one 
fitted instead. If you are not 100% confident of your competence to replace the mains plug (AC plug), the task 
should be carried out by qualified personnel.
NOTE: In-rush current is controlled and limited during the soft-start sequence. This enables multiple D Series 
Devices on the same AC mains circuit to be turned on simultaneously. 
9.1. Low voltage country considerations
Although the D Series has a wide range of operating mains voltage, some considerations can be applicable for 
low voltage regions. D Series performs well throughout the specified nominal voltage range but has slightly better 
efficiency at higher voltages. For regions with nominal voltage below 140 V, one could consider connecting the 
amplifier in a three-phase delta or two phase split-phase configuration.
NOTE: Following connections applicable only for resulting voltage inside the amplifiers nominal voltage range.
