Signal Distribution Phase Fuses - ETC SR12D Installation Manual

Pull out the black handle and
rotate the holder to access the
fuses. The top of each holder
contains a spare fuse.
Figure 7: Replacing a fuse
10

Signal distribution phase fuses

These fuses provide internal fault protection for signal distribution circuitry. If
a set of dimmer modules stops working and you cannot locate any other
cause, you should check the appropriate distribution fuses.
Each set of three fuses protects a twelve slot set of dimmers. In a 48 slot
SR48D rack, there would be twelve fuses. The first set of three, starting from
the left, would protect slots 1-12. The second set would protect slots 13-24,
the third 25-36 and the last set protects dimmers 37-48. Smaller racks have
fewer sets of fuses.
Note: The second fuse in the first set provides power for the cooling fan on
all rack models.
If a signal distribution fuse fails, you should to check the associated circuitry
and correct any faults before replacing the fuse. After eliminating any faults
you can replace the fuse with the spare located each holder.
1. Turn off all main power disconnect switches or turn off power to the rack
at the main circuit breaker.
2. Remove the CEM module and six dimmer modules above it to expose the
fuse block. See Releasing and securing module safety stops on page 11.
Each set of three fuses
protect a set of twelve
dimmer slots, starting from
the top of the rack: The first
three protect slots 1-12, the
second three slots 13-24, etc
The second fuse in the first
set also provides operating
power to the cooling fan
3. Pull out the handle of the fuse holder and rotate the block to access the
fuse you want to check or replace.
4. Rotate the handle 90° so it points down. You can now easily check and
replace the fuse.
5. Rotate the handle back and push it in to reinstall the fuse.
6. Reinstall the CEM and dimmer modules. See Releasing and securing
module safety stops on page 11
7. Close the door, reapply power and verify system performance.
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The fuse block is located on
the back of the rack just
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above the CEM backplane
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1 2 3 4 5
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This example shows the fuse
block for an SR48D rack
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Figure 6: Signal distribution fuse block
Electronic Theatre Controls, Inc.