P o w e r s y s t e m
Cooling Fan Board (motherboard fans)
This small board has the following important functions:
One power/signal ribbon cable socket for the cable from the
motherboard power distribution board, (1).
An input from the sensor switch of the side panel lock, (2).
Three power connectors for the fans, (3, 4, and 5). A small printed
graphic on the board indicates which fan connects to which socket.
One thermistor mounted on the board which serves as an ambient
temperature sensor, (6).
Fig 14-2 Cooling fan board
Uninterruptible Power Supply
The Uninterruptible Power Supply is a self-contained battery-backed unit
which supplies the system unit with all its power requirements. The
following is a list of its major features:
1000W maximum total DC output
Auto-ranging AC input voltage selection
48V DC input from backup batteries
Battery power circuit breaker
Constant voltage battery charging output
Remote control/monitoring facility
Cooling fans mounted on, and powered from, the power supply
Compliance with all relevant safety standards
Four 12V batteries mounted inside the power supply unit in a removable
pack provide backup power in the event of a mains electricity supply failure.
These batteries allow the system to function normally during a short power
failure. During a longer failure, the batteries allow the system to be shut
down in an orderly fashion, thereby preventing any data loss. Whenever the
AC supply is available, the power supply charges the batteries unless the
battery isolation switch (i.e. circuit breaker) is in the OFF position.