Power Cable Vendor Inspection

You may find this useful:

Cable Testing

A. Insulation System - To insure integrity of the cable insulation system after shipping, site storage, and pulling through conduit an insulation resistance test will reveal insulation deformities and moisture in the cable that otherwise might cause an untimely premature cable failure possibly damaging equipment or personnel. Perform the following on all customer power cables to and from main switchboard. This would include cables from utility transformer to MSB and cables from MSB to all secondary switchboards or distribution panels.

B. Visually inspect visible portion of cables for observable defects.

C. Insure all solid-state devices are disconnected from the system prior to meggering. Typically but not all-inclusive would be Meters, trip units with voltage sensing, and TVSS units.

D. Isolate cables by opening breakers. Meggering thru equipment like motors or transformers will produce erroneous readings.

E. Perform insulation-resistance tests on each line and load cable, phase-to-phase, phase-to-ground, phase-to-neutral and neutral-to-ground in each conduit. Megger at 1000 Vdc for 600 volt cable and 500 Vdcfor 300 volt cable for one minute.

F. Insulation resistance shall be above 100 ohms and preferably above one megohm.

G. Insure cable termination connections are tight after testing.

Could you please provide a few more details? Please include if this is a new job assignment or homework.

Your posting 79217
Hi, would you please provide me the detail of inspection in power cable purchasing process, which document need to be reviewed and which test must be witnessed?

Your posting 79218
I need to have the detail procedure for electrical insulator factory acceptance test? In inspection and test plan which items must be considered in document review and which one for third party inspector witness?

Your posting 79219
Hi, would you introduce some references for best practice for switchgear performance test in vendor shop?

Hi, depends to the purchaser if the value of order is great or different size and type ordered, it is also possible the purchaser to assign resident inspector in vendor shop.

But in most case purchaser decide the manufacture quality control and test reports to be review and some of important items to be witnessed by their inspector.

These items are:

Voltage and insulation resistance tests or alternative spark tests, dielectric power factor voltage test for 33Kv cable, Dimensional inspection on sample off-cut i.e. construction consistency, insulation thickness, external sheath screen, armours and mans of main components, Visual checking in respect of cable formation, core and external sheath colors, marking legibility and tsting on material sample i.e. conductor coating, insulation external jacket for elongation, heat strocle blending and characteristics of armour, metal and sheath components including zinc coating.

for more detail you may review following article

http://www.inspection-for-industry.com/third-party-inspection-for-power-cable.html

Refer to #1↑. Cables are usually tested after installation, according to British Standard 7671.

not specifially a test but the supplier should provide a certificate of compliance to say the cable has been tested and meets the relevent standards.

In no way does this remove the requirement to test the cable in accordance with BS7671 or your local standard.