MV-90 Cable Life Expectancy

[jatrottpe]

I am looking for Cable Life expectancy chart/formula for 5KV, MV-90 non-shielded, EPR Insulation with PVC jacket and the appropriate life expectancy de-rating factors assocaited with cable loading (80% loaded, 100% loaded), temp, etc.

The original cable was installed in 1970, An addiditonal feeder was added when motor was upgraded in 1984/5. (8000hp compressor)

I was under the impression that 30-50 years is a typical life expectancy, but I can not find written confirmation.

I am also contacting cable vendors, (waiting for the reply)

I have found information on XLPE insulation but not on EPR.

I know motors and transformers have the 10 degC rule of thumb (Every increase in temp of 10 deg C halves the life expectancy)

 

[weressl]

I am looking for Cable Life expectancy chart/formula for 5KV, MV-90 non-shielded, EPR Insulation with PVC jacket and the appropriate life expectancy de-rating factors assocaited with cable loading (80% loaded, 100% loaded), temp, etc.

The original cable was installed in 1970, An addiditonal feeder was added when motor was upgraded in 1984/5. (8000hp compressor)

I was under the impression that 30-50 years is a typical life expectancy, but I can not find written confirmation.

I am also contacting cable vendors, (waiting for the reply)

I have found information on XLPE insulation but not on EPR.

I know motors and transformers have the 10 degC rule of thumb (Every increase in temp of 10 deg C halves the life expectancy)

10Centigrade rule is applicable as it has to do with insulation aging.

Manufacturers will be the best source. The life will dependent on the purity of the compound, there used to be a manufacturer who had controlled this to the extreme with greet results as far as failure rate/ age matrix. Another manufacturer got on the bandwagon and used to offer a premium cable.

30-50 years is what the claim used to be, even though it is just based on laboratory tests and no guarantee is ever offered. Many other aspects will affect the cable life. Hi-potting is a destructive test. P/I index done periodically and corrected to temperature an humidity is a great indicator of deteriorating cable.