GE Industrial Solutions CAR2548DC series - Manual (Page 12)

GE Data Sheet
CAR2548DC series dc-dc converters
Input: -36Vdc to -75Vdc; Output: 48Vdc @ 2500W; 3.3Vdc or 5 Vdc @ 1A
December 6, 2013 ©2013 General Electric Company. All rights reserved. Page 12
Vin_UV_warn_limit (58): This is another warning flag
indicating that the input voltage is decreasing dangerously
close to the low input voltage shutdown level.
Status_word (79): returns two bytes of information. The upper
byte bit functionality is tabulated in the Status_word section.
The lower byte bit functionality is identical to Status_byte.
Fan_speed (D7): This register can be used to ‘read’ the fan
speed in adjustment percent (0 – 100%) or set the fan speed in
adjustment percent (0 – 100%). The speed of the fan cannot
be reduced below what the power supply requires for its
operation. The register value is the percent number, it is not in
linear format.
Invalid commands or data: The power supply notifies the
MASTER if a non-supported command has been sent or invalid
data has been received. Notification is implemented by setting
the appropriate STATUS and ALARM registers and setting the
SMBAlert# flag.
If a non-supported read is requested the power supply will
return all 0x00h.
Restart after a lachoff: To restart after a latch_off either of
four restart mechanisms are available. The hardware pin
Remote ON/OFF may be turned OFF and then ON. The unit
may be commanded to restart via i2c through the Operation
command by first turning OFF then turning ON . The third way
to restart is to remove and reinsert the unit. The fourth way is
to turn OFF and then turn ON ac power to the unit. The fifth
way is by changing firmware from latch off to restart. Each of
these commands must keep the power supply in the OFF state
for at least 2 seconds, with the exception of changing to
restart.
A successful restart shall clear all alarm registers.
A power system that is comprised of a number of power
supplies could have difficulty restarting after a shutdown event
because of the non-synchronized behavior of the individual
power supplies. Implementing the latch-off mechanism
permits a synchronized restart that guarantees the
simultaneous restart of the entire system.
A synchronous restart can be implemented by;
1. Issuing a GLOBAL OFF and then ON command to all power
supplies,
2. Toggling Off and then ON the Remote ON/OFF signal
3. Removing and reapplying input commercial power to the
entire system.
It is good practice to turn OFF the power supplies for about 20
– 30 seconds in order to discharge all internal bias supplies
and reset the soft start circuitry of the individual power
supplies.
Control and Read accuracy:
The estimates below are believed to be reasonable under most
operating conditions. However, these are typical numbers and
not hard bound values that cannot be exceeded. In most
nominal operating conditions the returned values are
significantly better than these estimates.
FUNCTION ACCURACY
Vout_command ± 2%
Vout_OV_fault_limit ± 3%
Iout_OC_warn_limit ± 4% of FL
OT_warn_limit ± 5C
Vin_UV_warn_limit ± 3%
Vin_UV_fault_limit ± 3%
Read_Vout ± 2%
Read_Iout ± 4% of FL
Read_temperature ± 5C
Read_Pout ±5%
EEPROM
The microcontroller has 96 bytes of EEPROM memory available
for the system host.
A separate EEPROM IC, with write protect features, provides
another 128 bytes of memory. This EEPROM contains the
following FRU_ID information:
EEPROM: model number, revision, date code, serial number etc.
Offset Length Value Description
00 7 Serial number
07 1 20 ASCII space
08 4 Date code [YY,WW], ASCII numeric value
0C 1 20 ASCII space
0D 17 Model#, ASCII alphanumeric value
1E 1 20 ASCII space
1F 1 Revision, ASCII value
20-FF 224 FF
LEDs
Three LEDs are located on the front faceplate. When the LEDs
are ON GREEN then input and output are normal.
When the FAULT_LED is RED then a fault condition exists and
the power supply may not provide output power. The table
below further defines these states: