Forensics

Electrical Consulting

Forensic Services Newsletter

Damage by contact between the rotor and stator on a DC tensioner motor on a steel rolling mill.

Electrical failures and breakdowns can be a problem area in insurance claims handling because of uncertainty as to whether the breakdown is covered or which policy applies. Forensic Services can provide considerable assistance in unraveling such claims. We are not designers or manufacturers of electrical equipment, but we are very skilled in failure analysis and have applied our techniques to a wide range of electrical failures with great success. To illustrate, at the end of this newsletter is a list of electrical equipment, which is based on our failure analysis case history.

Fire damage to stator assembly as a result of a poor workmanship during rewinding.

Electrical equipment has a finite life, which is partly dependent on the service environment. Accordingly, many failures occur because of poor housing design, incorrect installation, inadequate maintenance or simply the high humidity that characterizes many Asian countries. Our strong materials and corrosion background places us in a good position to recognize the signs of degradation that are a feature of many electrical failures. One of our consultants has published numerous papers in the field of corrosion and two others have attended NACE (National Association of Corrosion Engineering) courses in the USA and Canada. These skills are also of use when electrical equipment suffers corrosion damage during transit.

Flashover at the rotor bars of a slip-ring rotor resistance starter motor.

We have three mechanical engineers skilled in interpreting engine damage, from large gas turbines down to small vehicle power units. These skills are of use in unraveling electrical claims involving rotating equipment that exhibit equivocal evidence in terms of what happened first.

Overheating of starter transformer as a result of energizing for excessive time.

Another asset is our expertise in fire and explosion. Most electrical failures result in high, localized temperatures that can initiate fires and/or explosions, serious or otherwise. When insurers are faced with a number of policies, each with inclusions and exclusions, it can be useful to have a disciplined technical report that sets out what did happen in order and the consequences of those events. Many reading this newsletter will know of the arguments that can revolve around the term 'flashover'. We provide technical guidance that facilitates resolution of such claims.

Sooting on 11kV vacuum circuit breaker connection chamber as a result of flashover.

Apparently small electrical failures can result in claims for widespread damage. Our engineers can distinguish true damage from contamination and provide solutions for the second.

Finally, investigating electrical failures is best done with electrical and electronic engineers on board. We have three and they supervise investigations in this category of failures. They also have available the association between FSM and Rimkus, which gives us access to hundreds of USA based consultants.

Electrical Equipment Claims Carried Out by FM

Rotating Electrical Equipment
  • Alternators
  • Generators
  • Motors
  • Slip ring and brush failures
Switching and Switchboards
  • Alternators
  • Low voltage switchgear
  • High voltage switchgear
    • Vacuum circuit breakers
    • Oil circuit breakers
    • Air circuit breakers
  • Capacitor banks
Transformers
  • Dry type transformers
  • Tap changing transformers
  • Oil filled transformers
  • Protection systems
  • Bushings
Transmission
  • Overhead high voltage cables
  • Underground
  • Bus bar/bus duct systems
  • Protection systems
  • Insulation failures
Lighting

Ignition by fluorenscent, incandescent and high intensity discharge lights

Storage and Charging Devices

Ignition/flashover associated with dry cell, rechargeable dry cell, wet cell batteries, uninterruptible power supply systems, rectifiers and capacitor banks.

Lightning Claims

See previous newsletter at : Lightning Claims

Regards,





Barry Dillon