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IM-ENG-114/GB
4.1 GENERAL INFORMATION
The PS1550 is a modular voltage power system devised to furnish 24V. Its characteristics make it particularly suita-
ble for applications requiring flexible compact systems.
The PS1550 permits:
• Having dual power supply with redundant function and automatic detection due to voltage loss.
Output is guaranteed without variation in the following circumstances:
a) loss of one of the two voltage sources (the second automatically provides necessary power).
b) loss of a Line Module (the fault is automatically indicated by alarm relay and the second Line Module immedia-
tely supplies necessary power).
c) loss of one or more of the Power Modules (the remaining Power Modules automatically share the load – sharing
current – and fault is indicated by alarm relay).
IMPORTANT: WHEN THE SYSTEM IS POWERED BY TWO LINES THEY MUST BE ISOLATED FROM EACH
OTHER (THERE MUST NOT BE ANY POINTS IN COMMON ) OTHERWISE AN ADEQUATE ISOLATION
POWER TRANSFORMER MUST BE INSERTED IN SERIES ON ONE OF THE TWO MODULES.
• Hot plug-in Module insertion, including the fan box.
• Having a compact (19’’ for 4 stacked units) and powerful system (1 KW maximum output).
• Being able to choose maximum power output and minimizing available space thanks to its modular
construction.
• Having an efficient system (typical yield 80%) with minimum heat dissipation.
Moreover the system:
• Limits the inrush current value during the first start up (by NTC at 15
Ω
2W).
• Is protected against power surges (by a varistor with energy absorption of 71 Joules in 2 ms).
• Is protected against shortcircuiting at output (pushbutton function).
• Is thermically protected (each Power Module has its own thermal protection of 85 °C).
The power supply system is mounted 4 units high on a 19’’modular rack (1550/RFD) and cooled by forced ventila-
tion (three 100 m3/h fans are incorporated).
The chassis accepts a 1550/TB-IN Input Module, a 1550/TB-OUT Output Module, two (to obtain redundancy)
1550/LM Line Modules and one or more (up to six with current sharing) Power Modules (max. 7A each).
4.2 OPERATIVE RANGE
The PS1550 power system is capable of generating elevated power (up to approximately 1KW) with high efficiency
(about 80%) in a reduced space.
Notwithstanding the efficiency of the system, a substantial quantity of power (approximately 210 W with a nominal
load of 36A) is dissipated in the form of heat which must be eliminated in order to maintain the temperature within
acceptable limits.
The device consents considerable cooling by natural convection thanks to the large finned dissipators mounted on
the Power Modules. This solution permits function without forced ventilation and the operative area (characteristic
Voltage output/ ambient Temperature) is displayed in figure 1.
4. DESCRIPTION AND SPECIFICATIONS
