Woodward 8251-0008 UG Actuators

If this LED is turned on, verify that the fans in the power supply chassis are turning and free of dust and

other obstructions, and that the temperature around the power supply is less than 55 °C.

If the power supply is cooled down without delay, it can recover from this situation without shutting down.

This LED will turn off once the internal power supply heat sink temperature falls below approximately 90 °C.

POWER SUPPLY FAULT LED

—This red LED turns on when one of the supply’s three power converters

has shut down or one or more of the supply levels is below internally specified levels.

If this LED is on,check for a short circuit on external devices connected to the control’s power supply.

When redundant power supplies are running, current sharing circuitry balances the load to reduce heat

and improve the reliability of the power supplies. In the event that one supply needs replacement, this

feature also ensures hot replacement of the power supplies without disrupting the operation of the control.

Each main power supply has four LEDs to indicate power supply health (OK, Input Fault,

Overtemperature, and Power Supply Fault). See MicroNet Expansion Power Supply Troubleshooting

(Section 4.13.1) for a description of the LED indications.

Module Description

The MicroNet expansion chassis may use either single or redundant power supplies. A motherboard

located on the back of the chassis allows the two power supplies to form a redundant power system

providing two separately regulated, 24 Vdc, 12 A outputs; two separately regulated, 5 Vdc, 20 A outputs;

and two separately regulated, 5 Vdc precharge outputs to the control. Power output regulation, including

line, load, and temperature effects, is less than ±5%.