Overhead tns

[IQ Electrical]

Overhead TN-S. More common than you might imagine. Just tested a school on the Scottish border with one but a fallen tree had severed the earth on the overhead. DNO were out within the hour with a rather cool vehicle and 2 hours later, we had a Ze of 0.21 Ohms.
By the look of the fallen tree, I'd guess the school had been without an effective means of earth for many months...