Air Ventilation And Cooling Requirements; Ac Power Connection - Bose Entero 440 Installation & Operation Manual

6. Air Ventilation and Cooling Requirements

6. Air Ventilation and Cooling Requirements

7. AC Power Connection

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The amplifier is equipped with a forced air-cooling system with variable speed and temperature
controlled fans to guarantee low operating temperature and minimal ventilation noise. The air flow
takes place from the front of the amplifier to the rear.
In case any heat sink becomes too hot, the temperature sensor opens the respective output relay,
disconnecting the output load from the particular channel. In case the power transformer gets
overheated, a different sensor causes the output relays on all channels to open and to interrupt the
outputs. After cooling down to the appropriate operating temperature the relay contacts are closed
again automatically.
It is important to have adequate air ventilation space behind the amplifier to allow a proper air flow.
In case the amplifier is mounted into a closed rack, do not cover the front of the rack with doors. When
using racks with a closed backside, use fans on the rear rack panel (air flow to the inside of the rack).
For larger installations in rooms with insufficient ventilation or at temperatures above 25°C, we
recommend use of ventilation plates (1RU) between the amplifiers.
At room temperatures above 30°C we recommend use of airconditioning
The power amplifier must be connected only with the supplied three-wire safety
power cord with protective conductor (non-fused earthed conductor). Check for
the proper mains voltage before connecting the power cord. Damages caused
by wrong supplied power voltage will not be covered by warranty.
Always turn off and disconnect the amplifier from the mains voltage before
making any audio connections.
The power fuses are located on the back panel of the amplifier and can be
accessed from the outside. Use only the appropriate fuses as labeled.
After properly mounting and connecting the AC cord and the audio connections,
the unit can be switched on.
Number of separate power transformers integrated in the power supply of the different models:
Bose Entero 440: 1 power transformers (4 channels per transformer)
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Bose Entero 840: 2 power transformers (4 channels per transformer)
Bose Entero 4100: 2 power transformers (2 channels per transformer)
Bose Entero 4200: 2 power transformers (2 channels per transformer)
Bose Entero 4400: 2 power transformers (2 channels per transformer)
The POWER indication LED indicates that the amplifier has been turned on. The PROTECT - LED
will also light up and indicate active protection relays. This LED will turn off after about 2 seconds.