⑨

3.7.2. Buzzer status

POWER SUPPLY CONDITION

Buzzer status

No AC power to all PSU

OFF

AC present/Only Standby Output On

OFF

Power supply DC outputs ON and OK

OFF

Power supply failure

Beeping

3.7.3. LED indicator status

3.7.4. TTL signal

POWER SUPPLY CONDITION

OUTPUT CONDITION

NORMAL

HIGH

FAILURE

LOW

3.8 Load sharing

3.8.1. Forced Load Sharing

The +3.3V, +5V and +12V outputs shall have forced load sharing. The corresponding output

shall share within 5% at full load when operated in a redundant 1+1 configuration. The 5VSB

and –12V outputs shall not have forced load sharing between power modules.

Example of load share accuracy:

Power supply #1 = 20A

Power supply #2 > 19A and < 21A

3.8.2. Load Sharing Signal

The power supplies load share shall use a single load share bus signal connected between

each corresponding output. If the load sharing is disabled by shorting the bus to ground, the

power system shall continue to operate within regulation limits for loads less than or equal to

the full load rating of each power supply. The failure of one power supply shall not effect the

output voltages of the other supply still operating.

POWER SUPPLY CONDITION

Power system

status

Per Power Module

status

LED COLOR

RED GREEN

ORANGE

No AC power to all PSU

OFF

OFF

OFF

AC present/Only Standby Output On

ON

OFF

OFF

Power supply DC outputs ON and OK OFF

ON

ON

Power supply failure

OFF

Blinking

OFF