Alpha Technologies AMPS HP2 Power System Installation & Operation Manual page 65

6.5.2 Rectifier Rear Panel
Refer to the Cordex CXRF 48-2.4 kW manual for shelf power and communications connections details.
6.5.3 True Module Fail Alarm
The power modules have a "true" fail alarm that provides a true indication of the power module's ability to source
current. When the module's output current drops below 2.5% of the rated output, a low output current condition is
detected and the Module Fail detection circuit is activated. This circuit momentarily ramps up the output voltage
to determine if the module will source current. If no increase in current is detected, the alarm is acti-
Module Fail
vated. The module will test once every 60 seconds for the condition until a current is detected. The output voltage
ramping ceases upon detection of current. A minimum 2.5% load is required to avoid the alarm.
Ramp Test Fail
This load can be provided with the parallel system battery. Activation of this alarm could indicate a failed module
or a failed load.
To avoid nuisance alarms for Cordex rectifier systems without batteries, and/or with a very light load (below 2.5%
of the rated output), the ramp test should be disabled. Disable the Ramp Test via the controller.
6.5.4 Heat Dissipation
Each rectifier module is equipped with a front-mounted, variable-speed fan. The fan speed is determined based
on ambient temperature, temperature and the load. Air flow is front-to-rear with the exhaust air exiting throught
internal vents at the rear of the unit.
6.5.5 Over Temperature Protection
Blockage or obstruction to the air flow can result in the internal temperature to rise and reduce the output power
or even shut down the rectifier. The rectifier will resume normal operation when the temperature reduces to a safe
level. Over temperature shut down can also occur when a fan failure has occurred.
6.5.6 Wide AC Range
The rectifier delivers up to 2400 W of power between 187 Vac and 310 Vac input voltage. the rectifier can deliver
up to 1200 W between 90 Vac and 187 Vac. During start up the rectifier begins to provide power for input voltage
>95 Vac and shuts down if the input voltage drops below 85 Vac. The THD and power factor will be out of specs
for input >277 Vac.
6.5.7 AC Inrush/Transient Suppression
To prevent a surge on the AC input line, the inrush current of a rectifier module is limited to the full load steady
state line current. Modules are also protected from input lightning and transient surges in accordance with IEEE/
ANSI C62.41 Category B3 standards.
6.5.8 Soft Start
A soft start feature is used to eliminate an instantaneous demand on the AC power source. A soft start, some-
times referred to as a "current walk-in", works by gradually (up to five seconds) ramping up the DC output current
limit from zero to the actual or defined customer setting. The rectifier output voltage is ramped from the minimum
voltage to the float voltage. This feature along with Start Delay prevents any instantaneous surge demand from
the utility.
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