Cable Testing

FAI offers both on-site cable testing and laboratory material testing of your cables. LIRA Plant Engineers.jpg

 

 

 Lira Testing at a cabinet in a nuclear power plant

LIRA

Our flagship Non Destructive Examination (NDE) cable testing tool is: LIRA (LIne Resonance Analysis).  LIRA performs both a global and local assessment of your cable’s performance.   The global evaluation provides a complete assessment of the cable’s insulation performance.  The LIRA local assessments can locate and localize cable insulation performance (i.e., degradation) issues.

LIRA Features include:

  • In-situ cable testing performs local and global cable assessments 
  • Test all cable sizes from low and medium voltage cables to the high voltage cables used in the transmission and distribution industries
  • Accommodates both shielded and unshielded cables (two or more metallic cores)
  • Damage-free testing methodology using a very low voltage signal (5 VDC or less)
  • Short test time – less than 5 minutes (evaluation can be done elsewhere later)
  • Test inaccessible/buried/underground cables
  • No need to determinate de-energized connections (breakers open) 

Lira Transmission Cables    LIRA evaluation of Transmission Cables 

                                                                                                                                                                                                                 

 
Lira applicability chart 

 

The following is a brief summary of a typical LIRA test, using a 3-phase tri-plexed cable as an example.  Other cable types may have a slightly different procedure implemented.

1. Per plant procedures take the cable out of service
2. Ground both cable ends to dissipate all electrical charges
3. If the far end of the cable cannot be grounded, the test end should remain grounded for 24-hours prior to testing to avoid any lingering voltage on the line
4. At the test end of the cable, remove the ground
5. Connect the 2 LIRA test probes to 2 of the 3 phases (i.e., A-phase & B-phase)
6. Perform a LIRA test
7. Move the LIRA test probes to 2 different connections (i.e., A-phase & C-phase)
8. Perform a LIRA test
9. Move the LIRA test probes to the last 2 untested combinations (i.e., B-phase & C-Phase)
10. Re-ground lines
11. Move to other side of cable (if possible) and perform the same test sequence 

Lira Alligator ClipsSimple LIRA test lead connection via alligator clips. Shown is LIRA connection to ground and a Transmission cable

LIRA On site Testing of a Transmission cableLIRA On -Site Testing of a Transmission cable

 

Lira Example Output

 
 
 
 
 
 
 
 
 
 
Example LIRA output, with anomaly at 7.4 m
 
Lira Technology

TAN-DELTA

We use the HV Diagnostics Tan Delta test set for on-site evaluations.  Tan Delta / Dissipation Factor testing of MV cables is one of the most widely used and effective non-destructive methods of detecting aging and degradation in MV cables. 

Ten Delta

HIPOT

Hipot Test is an abbreviation for high potential (high voltage) Test and it is also known as Dielectric Withstand Test. A hipot test checks for “good isolation.”

Hi-Pot