Allen&Heath ML5000 SERVICE MANUAL - Manual (Page 15)

14 ML5000 Service Manual
The MPS14 Power Supply
The slimline MPS14 power supply uses linear post-regulated switch mode technology to generate the DC
voltages required by the console. It will operate from a wide range of ac mains input voltages. Full protection and
thermally controlled fan cooling ensures the power unit will operate consistently. The MPS14 also has a built in
combiner for connection to a second supply for backup.
Power Supply Installation
Free standing
The MPS14 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 or carpet.
Rack mounting
The MPS14 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 airflow 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 MPS14 unit. Forced convection, by means of a fan-tray, may be desirable in this situation.
Location
As with any power supply that contains switch mode technology, it is preferable to provide a degree of physical
isolation of the unit from other equipment, particularly that which carries low level audio signals, to avoid any
possible interference pick-up. For this reason the unit is provided with a long (2.9m) 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 MPS14. The console chassis is earthed, to the mains earth, via the power supply. When
rack-mounting the MPS14 care should be taken to avoid any possible “ground loops” in the system which would
introduce audible hum or buzz 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 MPS14 chassis are in electrical contact
through the fixing rails they share in the rack. The MPS14 has audio 0V and mains earth connected internally. If
a ground loop is formed operation of the ground lift switch on the rear panel of the MPS14 may improve the
situation.
ADVANCED TECHNOLOGY / HIGH POWER DELIVERY / AUTO COMBINING
+18V -18V +10V +48V ON PROTECT
CONSOLE POWER SUPPLY MPS14
PIN 1 = +10V @ 5A PIN 2 = +17V @ 7A
PIN 4 = A GND PIN 3 = A GND
PIN 6 = +48V @ 1A PIN 7 = -17V @ 7A
PIN 5 = D GND
FUSE
500W MAX 100V - 230V.AC 47-63 Hz ~
CAUTION: FOR CONTINUED PROTECTION AGAINST RISK OF FIRE REPLACE FUSE
ATTENTION: REMPLACER LE FUSIBLE AVEC UN DES MEMES CARACTERISTIQUES. WITH SAME TYPE AND RATING. DISCONNECT SUPPLY BEFORE CHANGING FUSE.
DO NOT OPEN. NO USER SERVICEABLE PARTS INSIDE. DO NOT OBSTRUCT VENTILATION OPENINGS.
THIS APPARATUS MUST BE EARTHED BY THE POWER CORD.
COUPER L'ALIMENTATION AVANT DE CHANGER LE FUSIBLE.
WARNING: TO REDUCE THE RISK OF ELECTRIC SHOCK DO NOT EXPOSE THIS APPARATUS TO RAIN OR MOISTURE.
T5A 250V
T
MAINS INPUT
A DIVISION OF HARMAN INTERNATIONAL INDUSTRIES LTD MADE IN ENGLAND S/No
AVIS: RISQUE DE CHOC ELECTRIQUE - NE PAS OUVRIR.
CAUTION