1200 amp dc power system

Product Information

Guardian Bulk M42 is a 10RU high 19” rack-mounted, 1200 Amp DC power system providing a bulk output of -48VDC.

The Guardian Bulk M42 1200 Amp DC power system incorporates 6 rectifier shelves accommodating up to 23 Guardian family high efficiency hot-swap rectifiers. A maximum total current of 1200A (N+1) is available.

The rectifiers are internally fan cooled with speed control which is a function of load and temperature, keeping acoustic noise to a minimum.

Guardian Bulk M42 1200 Amp DC power system incorporates the ACX Advanced controller which monitors system parameters, controls rectifier output, and provides alarms for system failures. The controller is hot-pluggable for easy field replacement in case of failure. There are 2 LED alarm indicators which indicate failures, (RED) Alarm and (YELLOW) Message. A third green LED indicates the controller is working properly. As standard ten form-C relay outputs provide the alarms for remote use. Two digital inputs and outputs are also provided as well as an SD card with sufficient capacity for more than 20 years data logging. The controller can be programmed by means of a remote PC web page display. Communication is by Ethernet LAN with SNMPv3 including alarm trapping. It also has provision for temperature compensated charging of an external battery. An LCD Display/Touchpad is included for local metering, status, and setup.

Guardian Bulk M42 1200 Amp DC power system is compatible with UNIPOWER’s free PowCom™ software which offers local and remote management through an advanced Windows GUI.


Features and Options
  • >96% Efficiency Rectifiers
  • 1200A (N+1) Capacity
  • Remote Monitoring & Control
  • Field Replaceable Controller
  • Ethernet Comm. with SNMPv3
  • 3 LED Alarm/Status Indicators
  • 10 Form-C Relay Alarms
  • LCD Display/Touchpad
  • Easy Installation
System Voltage-48VDC nominal | -53.5 float (factory default setting, user adjustable)
Maximum Capacity 1200A
No. Rectifier Slots 23
Bus Bars Lugs - ½” on 1¾” centers or ⅜” on 1” centers with oversized washers.
Voltage (rectifier module)1-phase 180-275VAC
AC Supply Configurations 1-phase 230/240VAC (L-N-PE)
2-phase 240VAC (L1-L2-PE)
3-phase (3-wire Wye) - 190/200/216/208/220/240VAC (L1-L2-PE / L2-L3-PE / L3-L1-PE)
3-phase (4-wire Delta) - 200/210/220/230/240VAC (L1-N-PE / L2-N-PE / L3-N-PE)
Maximum Input Current 18A per installed rectifier
Rectifier Power Factor>0.98 (typical)
MONITORING & CONTROL (ACX Advanced Controller)
Alarm Relays10
Local Interface 4 x 20 LCD, 4-key menu, USB / RS232, microSD card slot for data logging
Remote InterfaceEthernet / Modem using PowCom™ software package
Ethernet port allows monitoring and control over a TCP/IP network.
Web browser support + SNMPv3
LED IndicationsGreen - System ON; Yellow - Message(s); Red LED - Alarm(s)
External Digital I/O 2 x Inputs, 2 x Outputs (TTL Level)
Symmetry Inputs6 or 12 (can be redefined as analog inputs up to 100VDC)
Low Voltage Battery Disconnect (LVBD) Optional external: Programmable via system controller
Temperature Compensated ChargingOptional: Programmable via system controller
EMCEN 300 386 ; EN61000-6-3 (Emission) ; EN61000-6-2 (Immunity)
Safety CAN/CSA C22.2 No 62368-1:2014; UL 62368-1:2014; EN 62368-1:2014/A11:2017
Operating Temperature-40ºC to +55ºC
Storage Temperature-40ºC to +85ºC
DIMENSIONS, ins. (mm) 19.0 (483) W x 10RU H x 21.6 (553) D
Battery Disconnection System can provides voltage controlled disconnection of batteries using and external LVBD.
Boost Charging Manual time controlled or automatic boost charging with adjustable time and voltage levels.
Battery Tests Automatic or manual testing of batteries up to six times per year with a 10 test memory. Variables include test duration and end voltage.
Battery discontinuance test to ensure battery connection.
Enhanced Battery Monitoring Monthly logging of essential battery parameters including temperature, temperature hours, current, charging voltage and symmetry voltage, Data logged for 5 years.
Site Logs System tools developed to assist site management. Daily peak load and statistic logs available.
Symmetry Measurement Optional tool that measures batteries for early detection of thermal runaway.
Temperature Compensation Charging

Allows continuous adjustment of output voltage according to battery temperature.
Features include adjustable compensation factor and separate thresholds for high temperature alarms.