Alpha Technologies CXPS 48-1.8-i, 48V Pos Gnd - Manual (Page 22)

Argus Technologies Ltd. 053-990-C0 Rev A WC
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2.4.5 Heat Dissipation
Cooling of the module is front-to-rear with the exhaust air exiting at the back. The fan is variable speed; which is
determined by heatsink temperature and load.
2.4.6 Over Temperature Protection
Each rectifier module is protected in the event of an excessive increase in temperature due to component failure
or cooling airflow blockage. During over temperature conditions, the rectifier limits the output power as well as the
output current. If temperature continues to increase, a shutdown of the rectifier is initiated. The rectifier shall
restart automatically if the temperature has returned to a safe level.
2.4.7 Wide AC Range
For voltages above specifications, power factor and total harmonic distortion may be derated. For voltages
between 312 and 320Vac, the rectifier may not be operational but shall not suffer any damage.
Output power is derated below 176Vac. The module output power derates linearly to 900W @ 90Vac. The
module provides approximately 1150W @ 115Vac input.
0
200
400
600
800
1000
1200
1400
1600
1800
2000
85 90 100 110 120 130 140 150 160 170 176 208 240 312
Input Voltage (Vac)
Output Powe
r (W
)
Figure 8–CXRF 48-1.8kW module performance
1800W @ 176Vac
~1150W @ 115Vac
900W @ 90Vac
2.4.8 AC Inrush/Transient Suppression
The inrush current of the rectifier module is limited to the full load steady state line current to prevent surge on the
AC line. Modules are also protected from input lightning and transient surges in accordance with IEEE/ANSI
C62.41 Category B3.
2.4.9 Soft Start
To eliminate an instantaneous demand on the AC source, a soft start feature is employed. Soft Start, sometimes
referred to as “current walk-in”, works by gradually (up to five seconds) ramping the current limit up from zero to
the actual or defined customer setting. The rectifier output voltage is ramped up from the minimum voltage to the
float voltage.
2.4.10 Start Delay
The rectifier modules are equipped with a delay timer in order to stagger start a series of modules to prevent
excessive loading of generators upon start up. The built-in timer delays the turn on of the module depending on
the value selected (up to 120 seconds) via the CXC. A minimum one-second delay is preset to allow charging of
the input capacitors.