5
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Precautions
• Do not operate the appliance beyond its specified tem-
perature, humidity or power source ratings.
Do not use the appliance in an extreme environment
where high temperature or high humidity exists. Use the
appliance at temperatures 5 °C to +45 °C (41 °F
to 113 °F) and humidity below 85 %.
The input power source for this appliance is 120 V AC
60 Hz.
• Avoid shock and vibration
Shock or vibration may damage the HDD.
The HDDs are fragile especially when the HDD motors
are revolving and the HDD POWER indicator lights. Be
sure to turn off either switch: the POWER switch on the
rear panel, or the HDD POWER switch inside the front
lid: before you mount the unit into a rack or dismount it.
Do not move the HDD for 30 seconds after turning off
the power.
• Pay attention to static electricity
Put your hand on a metallic surface to discharge static
electricity before installation.
Do not touch components mounted on the HDD directly
with your hand.
Hold only the two sides of the HDD when installing.
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General
The extension unit WJ-HDE300 can contain up to four hard disk drives per unit to add available disk space to the digital disk
recorder WJ-HD316/WJ-HD309. Up to seven extension units can be connected to a digital disk recorder. The units can be
operated in RAID level 5* mode for high tolerance to disk error.
* RAID level 5 (Redundant Arrays for Independent Disks, independent data disks with distributed parity blocks)
RAID level 5 regards 3 or more drives as one drive, and it is possible to read data by automatically attaching error correc-
tion data even though one of the drives is broken. (It is impossible to read data if 2 or more drives are broken.)
RAID level 5 requires a minimum of 3 drives to implement.
When using the RAID function, logical disk size of the extension unit will be as below.
Logical disk size = Smallest size of the disk among the disks in the extension unit x (Number of the disks in the extension
unit - 1) The actual space may be several percent lower than the logical space.
* Important
When set to RAID level 5, the digital disk recorder will not access the HDD preinstalled in it, but will access only the HDDs
in the extension unit.
• Avoid condensation on the surface of the HDD.
If this happened, do not turn on the power of the appli-
ance and leave the appliance for around 2 hours.
Wait until the dew evaporates in any of the following
cases.
• The appliance is moved to a place significantly dif-
ferent in temperature or humidity.
• The appliance is moved out from an air-conditioned
room.
• The appliance is placed in an extremely humid
place.
• The appliance is placed in a room where a heater
has just been turned on.
• Consumable parts
Contact your dealer about replacement when the time
comes.
A hard disk drive needs replacing after a certain length
(depends on the model) of operation.
Cooling fans also need replacing after around
20 000 - 30 000 hours of operation.
• Do not block the ventilation opening or slots on the
cover.
To prevent the appliance from overheating, place it at
least 5 cm (2 inches) away from the wall.
• Avoid placing the unit on an inclined surface.
Otherwise, malfunction or damage to the disk may
occur. Place the unit horizontally.
