Car2912te series front-end, Preliminary data sheet, Fault management – GE Industrial Solutions CAR2912TE series User Manual

Page 19: State change definition, Hot plug procedures

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GE

Preliminary Data Sheet

CAR2912TE series front-end

Input: 90Vac to 264Vac; Output: 12Vdc @ 2900W; 3.3 or 5Vdc @ 4A Standby

October 21, 2013

©2013 General Electric Company. All rights reserved.

Page 19

a subset of paralleled front-ends during power up. If the

overload persists beyond the 20 second delay, the front-end

will revert back into its programmed state of overload

protection.

Unit in Power Limit or in Current Limit:

When output

voltage is > 10V

DC

the Output LED will continue blinking.

When output voltage is < 10V

DC

, if the unit is in the RESTART

mode, it goes into hiccup. When the unit is ON the output LED

is ON, when the unit is OFF the output LED is OFF.
When the unit is in latched shutdown the output LED is

OFF.

Restart after a latchoff: PMBus™ fault_response commands

can be configured to direct the power supply to remain

latched off for over_voltage, over_temperature and

over_current.

To restart after a latch off either of five restart mechanisms

are available.

1. The hardware pin Remote ON/OFF may be cycled

OFF and then ON.

2. The unit may be commanded to restart via i2c

through the Operation command by cycling the

output OFF followed by ON.

3. Remove and reinsert the unit.

4. Turn OFF and then turn ON AC power to the unit.

5. 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, set the

restarted successful bit of the Status_2 register.
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 ENABLE signal

3. Removing and reapplying input commercial power to the

entire system.
The power supplies should be turned OFF for at least 20 – 30

seconds in order to discharge all internal bias supplies and

reset the soft start circuitry of the individual power supplies.
Auto_restart: Auto-restart is the default configuration for

over-current and over-temperature shutdowns. These

features are configured by the PMBus™ fault_response

commands
An overvoltage shutdown is followed by three attempted

restarts, each restart delayed 1 second, within a 1 minute

window. If within the 1 minute window three attempted

restarts failed, the unit will latch OFF. If within the 1 minute

less than 3 shutdowns occurred then the count for latch OFF

resets and the 1 minute window starts all over again.

Fault management

The power supply recognizes that certain transitionary states

can occur before a final state is reached. The STATUS and

ALARM registers will not be frozen into a notification state

until the final state is reached. Once a final state is reached

the SMBAlert# signal is set and the STATUS and ALARM

registers will not get reinstated until a clear_faults is issued by

the master. The only exception is that additional state

changes may be added to the original list if further changes

are noted.

The power supply differentiates between internal faults that

are within the power supply and external faults that the

power supply protects itself from, such as overload or input

voltage out of limits. The FAULT LED, FAULT PIN or i2c alarm is

not asserted for EXTERNAL FAULTS. Every attempt is made to

annunciate External Faults. Some of these annunciations can

be observed by looking at the input LEDs. These fault

categorizations are predictive in nature and therefore there is

a likelihood that a categorization may not have been made

correctly.


Input voltage out of range:

The Input LED will continue

blinking as long as sufficient power is available to power the

LED. If the input voltage is completely gone the Input LED is

OFF.

State change definition

A state_change is an indication that an event has occurred

that the MASTER should be aware of. The following events

shall trigger a state_change;

Initial power-up of the system when AC gets turned ON .

This is the indication from the power supply that it has

been turned ON.

Whenever the power supply gets hot-plugged into a

working system. This is the indicator to the system

(MASTER) that a new power supply is on line.

Any changes in the bit patterns of the STATUS and

ALARM registers are a STATUS change which triggers the

SMBALERT# flag.

Note that a host-issued command such as turning the output

OFF will not trigger an SMBAlert# even though the STATUS

registers will change to indicate the latest state of the power

supply.

Hot plug procedures

Careful system control is recommended when hot plugging a

power supply into a live system. It takes about 15 seconds for

a power supply to configure its address on the bus based on

the analog voltage levels present on the backplane. If

communications are not stopped during this interval, multiple

power supplies may respond to specific instructions because

the address of the hot plugged power supply always defaults

to xxxx000 (depending on which device is being addressed

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