©Novinium, Inc. 2016, all rights reserved.
NRI 603 – Small Diameter Cables – SPR
Revised: February 19, 2016
Page
9
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URD Cables and Pressurization
Cables with small interstitial areas (space
between the strands) compared to the
insulation size need to be pressurized.
Typically, cables 250MCM and smaller
need to
be pressurized
. Extra fluid needs to be forced
into the strands with pressure.
If you have questions, contact engineering.
If the cable to be injected is of at least
350MCM size (Feeder) or is rated for a much
higher voltage level, follow the pressurization
procedure as stated in
NRI 613 Large
Diameter Cables (Feeder) - SPR
.
Figure 15:
Thin insulation compared to the
conductor.
1.
Flow rate signals the end of injection.
After pinning the outlet end, the flow into the cable will naturally begin declining as the fluid fills the
voids in the conductor.
Longer runs will take longer to drop.
The flow rate should eventually drop to 1cc/min or less.
If flow doesn’t drop to this level, there may be a leak somewhere in the system.
Search and repair fluid leaks at both cable ends.
If no leaks are found, there is either a fault or an undetected splice in the cable.
Locate and repair the splice or fault.
Re-inject the cable sub-segments.
