Rockwell Automation T823X Trusted Power System - Manual (Page 16)

Trusted
TM
Power System T823X
Issue 9 Dec 08 PD-T823X 16
4.1. Power Pack Features
4.1.1. Indicators
The Power Pack has two indicators on the front:
AC OK: The LED is green if the input voltage is within limits.
PWR OK: The LED is green if the Power Pack is healthy and within operating limits. If a fault occurs
with the power supply or a fan, the LED is amber.
Failure of an internal power pack fan results in shutdown of the output of the power pack.
4.1.2. Overcurrent Protection
The overcurrent protection limits the output current in the event of an overload. There are two overload
circumstances.
If the load is increased steadily a single Power Pack compensates by derating the voltage, hence at
40A (the specification limit) the voltage is derated to 18.75V. This derated voltage is on the limit of the
Trusted system modules’ specification. (Note: this gradual increase is not typical of a system fault.)
If 24V is maintained over a rapid current rise, the overcurrent protection will trip the power supply when
35A is reached. This rapid increase is more typical of a fault situation in a system.