The Cooling Subsystem; Lru Philosophy - Advantech AWMA – C250 Installation And Operating Manual

AWMA-C250
3.6 T C S
HE OOLING UBSYSTEM
The cooling subsystem of each unit includes the Fan and the harnesses provided for easy fan
replacement. The cooling fan is configured for 220 VAC operation (pulsed controlled by a speed
control PCB, which allows for a temperature dependent rotating speed).
3.7 LRU P
HILOSOPHY
The maintenance concept employed in each unit is to localize a malfunction or circuit failure
down to the level of an LRU (Line Replaceable Unit), extract the LRU and replace it with an
equivalent part provided in the spare kit. This procedure can be completed in the field, without
resorting to the costly practice of returning the entire system to the depot for servicing. The
philosophy is to configure the LRUs as building blocks with a specific function that can be
monitored by sensors and fault indicators on a real-time basis.
Each unit contains circuitry to protect itself from operational damage caused by abnormal AC,
DC, RF faults or insufficient cooling.
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