Maintenance Programs

Infrared Thermography Testing

Infrared Thermography testing is a non-destructive test that is performed to detect "hot-spots". These "hot-spots" are temperature differentials that may indicate problems such as loose electrical connections, unbalanced loads, poor contacts or overloaded circuits.

Sample IR Test Report (PDF)

Oil Analysis

A transformer's fluid not only serves as a heat transfer medium, it is also part of the transformer's insulation system. Carr & Duff performs Dissolved Gas in Oil analysis (DGA), screen tests, water content and can test for PCB content.

A DGA analyzes the type and quantity of gas dissolved in the transformer oil. The principal gases that are typically found are hydrogen, oxygen, nitrogen, carbon monoxide, carbon dioxide, methane, ethylene, ethane, and acetylene. Certain quantities and combination of these gases are indicative of: insulation overheating/overloading, liquid overheating, partial discharge (corona), or arcing in the transformer.

A screen test is a collection of physical, electrical and chemical tests for the oil. This test is also an indicator of how suitable the insulation liquid is for service.

PCB tests are for older transformers to ensure compliance with EPA regulations.

Transformer Liquid Coolant Analysis Sample Report

Dissolved Gas Analysis Sample Report (PDF)

Switchgear / Substation Testing

Switchgear installed by contractors in the late 60's and 70's to meet the increasing load demands of industry began to fail in the 80's and 90's. These failures have been documented and are available in the IEEE and Doble Engineering Minute reports. This failure trend will continue in spite of state-of-the-art changes in construction techniques and installation methods unless preventive maintenance steps are taken.

Carr & Duff provides switchgear/substation de-energized testing services. De-energized testing includes, but not limited to, cleaning and insulation and contact resistance testing. In conjunction with the IR testing, these additional tests allow us to evaluate the overall state of your switchgear/substation.

Fused Disconnect Inspection & Test (PDF)

Transformer Maintenance Test Sample Report (PDF)

Low Voltage Power Circuit Breaker Test Sample Report