Revision B MX28B-1200 PRODUCT MANUAL MX28B-1200/2400 9
4.2 Power Output Capacity
A single power box frame consists of six rectifier shelves, each shelf accommodating up to four
hot-plug, 50 amp rectifiers. A completely configured power frame with 24 rectifiers is rated at
1200 amps. Each additional power frame will add up to 1200 amps for a maximum total of
2400 amps using 48 rectifiers. A single master control unit in the first power frame provides
control and monitoring for the entire system.
4.3 Rectifiers
The rectifiers are APC Model MRF28H54BV with specifications as follows:
•=Input Voltage: 176-264V ac (230V ac nominal) @ 45-66 Hz
•=Input Current per Rectifier: 13.9 Amps @ 230V ac
•=Apparent Power Factor: 99% Typical, 98% Minimum
•=Output Voltage: 54.5V dc
•=Overvoltage Protection: Set at 59.5V dc
•=Output Current per Rectifier: 50 Amps Minimum Continuous
•=Power Output per Rectifier: 2800W Continuous, Vin > 198V ac
•=Efficiency: 91% Typical
•=Cooling: Fan cooled, front to rear airflow
•=Ambient Temperature: -25°C to 65°C Operational
4.4 Control Unit
The microprocessor-based power system control unit is 1U high (1.75”) and provides control
and monitoring functions. Features implemented are:
•=32-character alphanumeric display (2 lines by 16 characters)
•=LED alarm and status indicators
•=Standard voltage and battery charging control
•=Battery temperature compensation (optional temperature probe)
•=Monitoring of up to 18 shelves of four rectifiers each
•=Individual alarm monitoring of 72 breakers
•=Individual alarm monitoring of ten power distribution fuses
•=Eight alarm / annunciation relays (Major, Minor, and six user defined) with form C
contact outputs
•=Four external alarm inputs (either N.O. or N.C. contacts)
•=Control for two independent Low Voltage Disconnects (LVD’s)