Corrosion of Padmount Equipment SWEDE Conference Michael Navarro

Corrosion of Padmount Equipment SWEDE Conference Michael Navarro May 2006

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

New Installation 3

Example of Corrosion - Transformer 4

Example of Corrosion - Transformer 5

Change Out - Transformer Missed opportunity to correct problem 6

Example of Corrosion - Transformer 7

Example of Corrosion - Transformer 8

Example of Corrosion - Transformer 9

Example of Corrosion - Switchgear 10

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

Trial & Error 12

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

Manufacturer’s – Transformer Cabinet Standard Stainless Steel 14

Stainless Steel – Transformer Cabinet 15

TXU Electric Delivery – Current Solution • 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 16

Switchgear With 12” Skirt 17

Corrosion of Padmount Equipment SWEDE Conference Michael Navarro May 2006