Which type of cable testing is best for initial suitability assessment but not for detailed numerical acceptability?

The most appropriate type of cable testing for an initial suitability assessment, rather than for detailed numerical acceptability, is tan-delta testing. This method evaluates the insulation's ability to handle electrical stress and provides insight into the quality of the insulation material. It primarily focuses on the dielectric properties of the insulation, informing users whether the insulation is generally suitable for service without delving into precise quantitative measurements.

In contrast, other testing methods serve different purposes. Dielectric insulation testing predominantly measures insulation strength and can reveal severe insulation faults but requires detailed interpretation of results for acceptability. Insulation resistance testing checks the resistance of the insulation to leakage currents, offering useful insights but again does not typically provide the depth of information needed for detailed assessments. Partial discharge testing, while valuable for locating potential insulation failures or weaknesses in the cable, is more geared towards ongoing monitoring rather than initial viability assessments.

Therefore, tan-delta testing stands out as it aligns best with a preliminary evaluation approach, providing sufficient insights without overwhelming specifics.