Siemens Maxum II Reference Manual page 14

Electronic Compartment Component Descriptions and Maintenance Procedures
2.1 Power Supplies
Output Connections
Output 24 VDC is supplied to components within the Maxum II via a cable harness that exits
the backside of the PSM. The cable terminates in quick disconnect connectors. Typically, a
white connector supplies 24 volts to the SYSCON2.1 cage and an orange connector supplies
24 volts to the PECM, where it is distributed to various modules in the EC. DC/DC converters
in the modules generate the other voltage levels needed by various circuits.
Fuse Replacement
The Power System Module is equipped with a fuse (Siemens Part Number A6X19905350).
This fuse is located on the front of the PSM just above the power cord plug. The fuse is a 250
V, 4.0 A, "slow-acting" type. Although this fuse rarely fails, replacement is simple (disconnect
power to the analyzer first). To remove the fuse, unplug the power cable that comes from the
PECM. Access the fuse by removing the fuse cap with a large blunt screwdriver.
Specifications
Voltage Range
Line Frequency Range
Nominal Input Current
Nominal Output Voltage
Nominal Output Current
Static Load
Dynamic Load
Overcurrent Cutoff
Overvoltage Cutoff
Overtemperature Cutoff
Power Fail Transitions
Electric Isolation
Dimensions
Cooling
Output Wiring
14
115 VAC (85 to 140 VAC), 230 VAC (185 to 264 VAC)
47 to 63 Hz
2 amp @ 115 VAC, 1 amp @ 230 VAC
24 VDC ±3%, 1% ripple plus noise at a bandwidth of 30 MHz
6 A @ < 104°F (40°C)
4 A @ 104° to 150°F (40° to 70° C)
0.2 A; 0.0 A open circuit permitted
Between 0.2 A to 3 A in the load range. A maximum load of 2 A at 1.8 kHz is
switched. Switching is controlled by pulse width. Precision range is not exceeded
in this operational mode.
Cutoff starts at 6.4 to 7.5 amps. When current drops, device switches on.
Cutoff starts at 27 to 31 VDC. When voltage drops, device switches on.
After temperature decreases to specified tolerance, device switches on.
Occurs 20 ms after a primary power failure. Should a power failure occur, a low
20 ms signal is generated.
Input/Output: 3.7 kV
Length: 10.24 inches (260 mm)
Width: 2.36 inches (60 mm)
Depth: 3.54 inches (90 mm)
Convection and conduction through aluminum mounting plate.
Cable harness
Maxum II Reference Manual
Manual, 7/2017, 2000596-001