Metso Automation MAX Controls
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Chapter 4
DPU Battery and
Fuse Maintenance
Battery Types
The Model PDP DPU uses two battery types that must be replaced
periodically. A Nickel Cadmium (NiCd) rechargeable battery pack, mounted
on the motherboard, allows the DPU to preserve its database when power
goes down. This battery, tested for one minute every hour, will raise a "bat-
tery #2 weak" battery low alarm if it fails.
The DPU Control Processor Card uses a 360 maH Lithium battery to
preserve CMOS settings and time and date. If this battery fails, a "battery #1
weak" battery low alarm will be raised. The battery has a shelf life of 10
years under "no load" conditions. When the DPU is powered, the battery is
electronically disconnected. The Control Processor Card battery will last for
more than two years if no power is applied to the board.
Caution
: The DPU contains devices that can be damaged by electrostatic
discharge. It is imperative that the DPU be carried in antistatic protective
bags. Grounded workstations and wrist straps must be used when
adjusting or performing any work on the DPU. If soldering irons are used,
they must also be grounded.
Replacing the NiCd Battery Pack (Battery #2)
Note:
when the DPU is shipped or put in storage, always unplug the NiCd
battery pack from the P10 connector.
The DPU NiCd battery pack (Part number 081537) should be replaced at
least every three years. Spare NiCd battery packs have a shelf life of 5 to 7
years.
The battery is located in an accessible compartment on the upper right side
of the DPU. To access the battery, you must remove the DPU from the rack
as described in the following procedure:
