MSA SUPREMA - System Power Supply; EXT Terminals (External Power Supply, 24 VDC); INT Terminals (MSP-Module, 24 VDC, 150 W); BAT Terminals (Backup Battery Power Supply)

REV 0, June 2005 Page 35
Operation Manual SUPREMA
3. Description of the System
3.7 System Power Supply
The system is supplied with 24 VDC Three pairs of terminals are provided, so that the power
can be taken from 3 different sources (redundancy). The supplies are functionally equivalent,
but the power draw is prioritised as follows: 1
st
= EXT, 2
nd
= INT, 3
rd
= BAT. The changeover
from one source to another is accomplished by hardware means in the system modules.
When an external power pack or battery supply is used, the power should be filtered through
an appropriate EMC [electromagnetic compatibility] filter. The EMC and low-voltage guidelines
should be followed.
3.7.1 EXT Terminals (External Power Supply, 24 VDC)
• Connection for voltage supply from an external power supply unit; power is sent to all
units in the rack.
• Required when a redundant power supply is provided or when the internal rack power
supply is not sufficient to operate all of the sensors.
• Maximum supply current of 20 A for one rack.
3.7.2 INT Terminals (MSP-module, 24 VDC, 150 W)
• Connection for voltage supply from an internal rack power supply or an external power
supply unit.
• Power supplied to all rack units and the sensors.
• The internal power supply unit (MSP-module) has a supply voltage input of 85 ... 265
VAC (47 ... 63 Hz) or 120 ... 330 VDC.
• If the rack power supply unit cannot supply enough power, the sensors, modules, or
relays must be supplied by external power supply units.
• The internal rack power supply can be omitted if, because of a high power requirement
or a redundant design, the power is being supplied by an external power supply via the
INT terminals.
• Maximum supply current of 20 A.
3.7.3 BAT Terminals (Backup Battery Power Supply)
• Backup battery power supply for all units of a rack (20 ...28 VDC).
• If the internal and/or the external power supply fails, the system receives its power here.
• Maximum supply current of 20 A.
3.7.4 Features of the System Power Supply
• The customer is responsible for providing a safety cut-out (maximum rack power,
480 W).
• The 85 ... 256 VAC is supplied via screw terminals directly on the power supply unit.
• The system is supplied with an operating voltage of 24 VDC (19.2 ... 32 VDC).
• 3 pairs of terminals for the connection of three 24 VDC power supply sources (EXT, INT,
BAT) are provided on the Interconnection Board (MIB module).
• The EXT, INT and BAT voltages are supplied to each system module.