Allen&Heath RPS9 - Manual (Page 4)

4
Installation of the RPS9
Free Standing
The RPS9 can be operated as a free standing unit without requiring any special cooling arrangement, but should not be
accidentally or deliberately covered in any way. Always stand the unit on a firm flat surface well away from any soft furnishings
such as carpets or curtains.
Rack Mounting
The RPS9 is designed as a 19 inch rack mount unit and will occupy 2U (3.5 inches) of rack space.
An important consideration when rack-mounting the unit is the need for natural convection of air flow over the whole unit.
Good ventilation below the unit, in the floor or back of the rack, will ensure a path for continuous air flow.
Other equipment in the rack which is known not to produce a significant amount of heat should be mounted below the unit.
Equipment which also relies on good air flow within the rack (i.e. most power amplifiers and other power supplies) should be given
due consideration and some space should be provided between such units and between the RPS9 unit. Forced convection, by
means of a fan-tray, may be desirable in this situation.
Location
As with any power supply that contains a mains voltage transforme r, it is recommended that the RPS9 is physically separated from
other equipment, particularly that which carries low level audio signals, to avoid any possible hum pick-up. For this reason the unit
is provided with a long (3m) output cable to enable it to be positioned away from the mixing console. For the same reason, when
rack-mounting it is preferable to avoid locating the unit adjacent to signal processing equipment.
Earthing
Finally; some consideration should be given to the earthing arrangement of the system at the centre of which is the console and
the RPS9. The console chassis is earthed, to mains earth via the power supply. When rack-mounting the RPS9 care should be
taken to avoid any possible “ground loops” in the system which would introduce audible hum to otherwise clean audio signals.
Ground loops may occur where signal processing equipment, patched to the console, has its signal earth connected to the
equipment chassis. A ground loop is formed if the chassis of the signal processing equipment and the RPS9 chassis are in electrical
contact through the fixing rails they share in the rack. The RPS9 includes a “ground lift” switch on the rear panel. This isolates the
audio 0V from the chassis earth. Operation of this switch may alleviate hum caused by a ground loop. Note that this will not
disconnect the console chassis from mains earth, which must remain connected at all times.
Using the RPS9
ALWAYS MAKE SURE THAT THE POWER SUPPLY HAS BEEN SET TO THE SAME AC
MAINS VOLTAGE AS PROVIDED FROM THE MAINS SOCKET OUTLET
Always switch the power supply off before connecting or disconnecting the console power cable, removing or installing modules
and servicing. In the event of an electrical storm, or large mains voltage fluctuations, immediately switch off the power supply and
disconnect from the mains supply.
During normal operation some heat is generated. This is dissipated by the rear heatsink and chassis ventilation.
DO NOT COVER THE UNIT DURING OPERATION