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)