Corrosion of Padmount Equipment SWEDE Conference Michael Navarro May 2006

2 TXU Electric Delivery Serves 402 cities in Texas - 3M Electric Delivery Points

3 New Installation

4 Example of Corrosion - Transformer

5

6 Change Out - Transformer Missed opportunity to correct problem

7 Example of Corrosion - Transformer

8

9

10 Example of Corrosion - Switchgear

11 Sprinkler Systems Fertilizer Pipelines Hard Water Below Grade, Standing in Water Heat Soil Conditions Accelerants of Corrosion

12 Trial & Error

13 Transformers - Complete overhaul of padmount transformer location, to include replacing with stainless steel transformer  Impacts –Cost Standard 50KVA Minipad - $1,100 Stainless Steel - $1,400 Change-Out Labor- $400 Spill, Clean-up, Disposal - $1,250  Customer Satisfaction  Lost Revenue (??) TXU Electric Delivery – Current Solution

14 Manufacturer’s – Transformer Cabinet Stainless Steel Standard

15 Stainless Steel – Transformer Cabinet

16 Switchgear Costs:  Base Spacer/Skirt –Mild Steel (Standard) - $1,000 –Stainless Steel - $1,600  Switchgear w/o Base Spacer/Skirt –Standard Cabinet - $10,000 –Stainless Steel – 4 to 5 times higher TXU Electric Delivery – Current Solution

17 Switchgear With 12” Skirt

Corrosion of Padmount Equipment SWEDE Conference Michael Navarro May 2006