1. Caryn Riley, Josh Perkel, Ray Hill, and Nigel Hampton NEETRAC
Combining HV & EHV Cable Qualifications Understanding the Risk side of the Risk / Benefit
Caryn Riley, Josh Perkel, Ray Hill, and Nigel Hampton
NEETRAC

2. Qualification Landscape
Numerous philosophies & standards may be used to qualify a Transmission Cable System
CABLE SYSTEM
IEC & AEIC
CABLE
ACCESSORIES
IEC- HV & stress limited
JOINT
TERMINATION
ICEA
IEEE 404
IEEE 48
AEIC
COMPONENT 2

3. Segments of Type Tests Pre Tests Post Tests Water Tests Load Cycles
Number
Temperature
Time Window
Environment HV
EHV
System
IEC 60840
Clause 12
IEC 60267
Cable
Clause 13
ICEA 720
Accessories
Clause 14
System Survival
IEC & AEIC
Post Tests
Water Tests 3

4. Temperature Constraints
IEC
ICEA
Number of thermal cycles 20
Max Cond Temp
95 – 100
100 – 105
Locn Temp Measurement
Hottest Point
Cycle End Temp
None
Time in window
Any 2 hours
Hr 6 to Hr 8
Heating Time
8 hours
Cooling Time
16 hours
Conduit
Permited
Required
It is possible to determine a Time / Temperature Recipe that fulfills these requirements on the large loop required 4

5. Thermal Profile Impact - ICEA
2 step
A complicated cycle increases the chance of a “missed” cycle
but the system experiences the ageing of the missed cycle 5

6. Type Test Architecture – add cable
Pre Tests
Post Tests
Load Cycles
Number
Temperature
Time Window
Environment
Water Tests
Term
Term
Cable
Term
Term
Cable
Term
Cable
Joint
Term
Cable 6

7. Reliability of Cycle Multiplier Cycles / Time (hrs) of Exposure
Min Number of Cycles
Reliability of Cycle Multiplier
Cycles / Time (hrs) of Exposure
On Test
IEC / ICEA 20
1.1
22 / 2
Outcome mid 2015)
Component – IEC Test
Established Designs
Mean Incident Rate
Electrical
(%)
Cable
<5
Joint 40
Termination
(incl GIS) 15
WHY
Design Evolutions
Non Robust Qual
lucky pass
reach in “Range of Qual”
Inadequate Training
Workmanship 7

8. Architecture Risk Consider survival of component 85% 95% 85%
TOTAL RISK 36%
CABLE
QUAL RISK 10%
TOTAL RISK 20%
QUAL RISK 5%
85%
95%
85%
85%
95%
TOTAL RISK 54%
CABLE QUAL RISK 10%
60%
95%
85% 8

9. Impact of Components on Risk

10. Recovery
Recovery needs
Planning
Extra Lengths
Extra Components 10

11. Conclusions
Engineers like to include many components to maximise coverage.
Successfully completion is by no means guaranteed.
The risks are different for each component type and increases with number.
The more complicated the loop, the higher the risk (generally).
Recovery when components fail is possible but must be built in at the start
Must repeat some or all of the test program depending on what failed and when
Must balance risk with potential benefit 11