Contemporary Control Systems EXP Expansion Modules User Manual - Manual (Page 22)

–PWR This LED should also be lit when the MOD HUB is
powered. This LED monitors the internal negative DC power to
ensure that it is operating within an acceptable power range. If
this indicator is not lit when the hub is turned on, there is a
problem with the internal negative power supply.
If neither the +PWR nor the –PWR indicators light when the
MOD HUB is turned on, check for a blown fuse in the
MOD HUB.
To open the fuse box on the front panel of the MOD HUB
(domestic models only):
Turn off the MOD HUB by depressing the power switch
located on the right side of the front panel of the MOD
HUB. Unplug the power cord from the power receptacle on
the front panel of the MOD HUB.
Locate the fuse box (between the power switch and the power
receptacle on the front panel of the hub). Gently place the wide
edge of a screwdriver beneath the fuse box cover and lift to
dislodge the cover.
Lift out the fuse attached to the fuse box cover and check the
fuse. The fuse is blown if the wire in the fuse is broken.
If the fuse is blown, replace it with the spare 5 mm x 20 mm
fuse located in the fuse box cover, and then close the fuse box,
reattach the power cord, and turn on the MOD HUB.
If, after replacing the fuse, the +PWR and –PWR indicators still
do not light up when the hub is turned on, call technical support.
Note: Export models do not have spare fuses. Both fuses in
the fuse holder are actively used.
TIMING
If no cables are connected to the MOD HUB or if
no valid ARCNET activity is present on any one port on the
MOD HUB, this indicator is off. If ARCNET activity is present
and the internal regeneration of the ARCNET signal is proper,
this indicator will light, telling you that the MOD HUB is
receiving ARCNET signals and (faithfully) reproducing these
TD401600-0M
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