Professional Engineering & Investigation Services

Anderson Engineering & Investigations are professional engineers experienced in manufacturing engineering, product and process failure mode analysis, electrical, mechanical, and forensic engineering including fire investigation services.

When you need answers you can trust, Anderson Engineering & Investigations will provide you with timely, understandable results.

Burden of a Current Transformer

A current transformer converts a high primary current with a secondary winding around a magnetizable core to a lower secondary current. A current transformer is passive, therefore no external power supply is connected, and what is secondary connected forms a load for the current transformer. In short, the connecting wires and the connected meter form the load of the current transformer. In technical terms this is called load in VA (volt amps). This load is of influence on the accuracy of the current transformer.

In the design of the current transformer, internal losses and the external load of the current transformer are taken into account. The current transformer acts as a current source. Therefore, the Midwest Current Transformer designers take the burden of the current transformer into account.

The IEC 61869-2 standard for current transformers specifies the following about the load of the current transformer:

The load of a measuring transformer is between 25% and 100% of its nominal load. The idea behind this is that when the load of the current transformer is too low, it may no longer comply with the class and can return a value that is too positive.

Knowing your burden and calculating your VA is the key to finding the proper current transformer for your application.

The VA rating of the current transformer is determined through two straightforward equations.

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The Case of the Dog Food Stealing, Fire Starting Mouse

Blaze Fire Investigation is now know as Anderson Engineering. (updated 6/28/17)

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Using Drip Loops Could Save Your Fish and Your Home

Blaze Fire Investigation is now know as Anderson Engineering. (updated 6/28/17)

Saltwater aquariums are fascinating and beautiful.  Having a little piece of the ocean inside your home has been attracting hobbyist for years.   However, not all hobbyists are aware of the dangers and risks that are associated with keeping a saltwater aquarium.

It was the start of a beautiful day in Memphis, TN until the owners of a 90 gallon saltwater aquarium woke up to the smoke alarm sounding in their home.  They ran into the living room and saw flames shooting up behind their aquarium.  They immediately grabbed the phone, called 9-1-1 and ran out of the house.  The fire department came and extinguished the fire. Unfortunately, the glass tank broke during the course of the fire and all the aquarium inhabitants were lost.

Our team of experts examined and photographed the fire scene and collected all of the aquarium equipment in the home. The aquarium equipment consisted of a water pump, heater, protein skimmer and two fluorescent light fixtures.  All of this equipment was plugged into a relocatable power tap that was located on the floor behind the aquarium.  A detailed examination of all of the aquarium equipment showed the most severe damage was located at the power tap.  The power tap’s plastic housing was melted and charred and sections of the hot and neutral busses were visible.  See photographs below.

The hot and neutral busses showed evidence of melting and a short section of both of the buses was melted away.  Analysis showed that arcing occurred between the line and neutral busses in the power tap.  These busses are normally separated by an air gap and insulating plastic material.  In order for an arcing event to occur internal to the power tap, a current path must be established across the insulating materials.  Arcing across an insulating material is known as arc tracking and is commonly due to contamination on the insulating surfaces.  In this case the contamination was caused by the saltwater from the aquarium. 

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Can There Ever Be Too Many Holiday Lights?

Blaze Fire Investigation is now know as Anderson Engineering. (updated 6/28/17)

It is that time of year again where many people have decorated for the Holidays!  Twinkling lights are shining on rooftops, trees and all over the lawns of our friends and neighbors.  Most people know that one person that makes it their mission to have the most beautiful and colorful yard in the neighborhood. If you don’t, you have probably seen the movie National Lampoon’s Christmas Vacation staring Chevy Chase!  What lots of people don’t think about is how much power all of their lights consume and how much is too much for the extension cord, outlet or electronic device that they have the lights plugged into.

Every electrical device has a voltage and maximum power rating. The amount of power it takes to light a string of holiday lights varies depending on the type of light and the number of lights in that particular string. For example, a typical 300 light string can consume 72 Watts of power.   How many Watts of power are your lights, holiday decorations and devices rated for?

Our investigators at Blaze Fire Investigation and Anderson Engineering were involved in an origin and cause investigation of a holiday light device that synchronized the twinkling of the lights with holiday music. This particular device had a maximum power rating of approximately 400 Watts. Burn patterns pointed directly at this device as being a possible cause for this fire.

Our team of origin and cause experts and engineers examined the evidence, performed testing on exemplar products and were able to determine that the origin of the fire was internal to this holiday lighting device.  Testing results showed the over wattage of the device could cause a component inside the device to fail in an unsafe manner and ignite the flammable plastic housing of the device without tripping any circuit breakers in the house or blowing any fuses in the device or holiday lights themselves. 

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Why Liz Works at Blaze Fire Investigation

Blaze Fire Investigations is now known as Anderson Engineering. (updated: 6/28/2017)

When you call the Blaze Fire Investigation office, Liz Rockwell will probably be the person who you talk to first. On the Blaze team for more than three years, Liz provides the administrative wheels that move client cases from in-take to final report. Administration and operations intertwine in Liz’s day. She may be dispatching investigators, finalizing reports, scheduling appointments, or managing the office bookkeeping. Her many skills and attention to detail allow her to provide clients with the best customer service while enabling the investigators to focus on what they do best.

Working at Blaze Fire Investigation provides Liz with many things other than a paycheck. She finds the industry to be very stimulating. “You never know what situation is next.” she says. While her position holds a great deal of responsibility, the owners grant her the autonomy and tools to get the job done in the manner that she feels is most efficient. Her opinions are heard and valued. As the mother of a young son, Liz appreciates the flexibility that the company gives her to adjust when the need arises.

The Chicago office where Liz works operates as a hub for the Blaze and Anderson Engineering teams that are spread out through several states. The company has worked hard to develop a culture that supports and enables all employees to serve clients with a team approach. While Liz is the administrative wheels, she knows she's not driving by herself.

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