Insulated power cable

1. A transformer containing an insulated power cable comprising:

a) a multi-strand cable comprising a plurality of uninsulated wires, and

b) electrical insulation sheathing the cable, the electrical insulation having a thickness of from 0.0625 to 0.5 inches (0.16 to 1.3 centimeters) and comprising a plurality of layers of spirally-wrapped, creped tape, the tape being comprised of at least 50 percent by weight of an aramid material, the tape having a density of from 0.1 to 0.5 grams per cubic centimeter prior to being creped;

wherein the transformer employs oil as insulation and in use of the transformer a temperature difference of 60 degrees C. can be maintained between oil in the transformer and conductor in the cable.

2. The transformer of claim 1 wherein the density of the electrical insulation sheathed on the cable is from 0.2 to 0.6 grams per cubic centimeter.

3. The transformer of claim 2 wherein the density of the electrical insulation sheathed on the cable is from 0.3 to 0.5 grams per cubic centimeter.

4. The transformer of claim 1 wherein the aramid material is a nonwoven sheet comprising aramid fibers.

5. The transformer of claim 4 wherein the nonwoven sheet is an aramid paper.

6. The transformer of claim 1 wherein the aramid material is a meta-aramid polymer.

7. The transformer of claim 6 wherein the meta-aramid polymer is poly(metaphenylene isophthalamide).

8. The transformer of claim 1 wherein the aramid material is a para-aramid polymer.

9. The transformer of claim 8 wherein the para-aramid polymer is poly(paraphenylene terephthalamide).

10. The transformer of claim 1 wherein the plurality of uninsulated wires are present in the form of a plurality of bundles.

11. The transformer of claim 1 wherein the multi-strand cable has a size from 8 AWG to 1000 MCM.