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.

Continue reading

Technical Parameters of an Instrument Current Transformer

The current transformer is one in which the unit measures the current of another circuit. It is combined with an ammeter within its own circuit to carry out this measurement. Measuring high-voltage current in a direct manner requires the insertion of a measuring instrument into the circuit. This is an unnecessary task and problem which would lower the current it is meant to measure.In addition, the heat generated in measuring equipment from the high current would provide inaccurate readings. However, measuring the current in an indirect manner with a current transformer is much more practical and accurate. At Midwest Current Transformer, our work involves the manufacture of standard and custom design instrument current transformers to meet various industry requirements.

Continue reading

Is There a Difference Between A Donut And Toroidal Current Transformer?

Toroidal current transformers are power transformers containing a toroidal core upon which the secondary and primary coils are wound. These current transformers obtain their name from the donut like shape. The transformer consists of a circular magnetic core around which wires wrapped. They are used in numerous AC electronic circuits. Therefore, there is no difference between a Toroidal and donut transformer, with both terms referring to the same device.

Continue reading

How Do Toroidal Transformers Work?

Toroidal transformers are used in electronic applications that step up or down a voltage or for the isolation of electronic equipment from a source of voltage. Different transformers are used for different applications. It is important to be careful in choosing the right transformer unit for your requirements. At Midwest Current Transformer, we offer toroidal transformers (CT) for a wide range of power applications.

Continue reading

Why are Current Transformers Necessary?

Power systems are wide-ranging and complex in nature. You cannot actually see electricity, but you can understand how it operates. One of the important elements of an electrical power system is the current transformer. At Midwest Current Transformer, our focus is on manufacturing standard and custom transformers to fulfill the requirements of our customers.

Some important information about current transformers is explained below.

Continue reading

How Does A Current Transformer Work?

A current transformer is a category of instrument transformer designed and manufactured to generate an alternating current in its second winding. This current is directly proportional to the current measured in its primary winding. At Midwest Current Transformer, we offer our customers high-voltage transformers to meet various industrial applications.

Continue reading

Things to Know About Current Transformers

A current transformer only has one or a few number of turns as its primary winding. This primary winding can consist of simply a bus bar or conductor position through a central hole, or a coil of heavy-duty wire wound around core. At Midwest Current Transformer, we offer a wide range of high-voltage transformers to our customers.

Continue reading

CT Circuits – The Importance of Grounding the Secondary Side

Midwest Current Transformer is one of the most trusted sources for current transformers in the industry. We offer a wide range of transformers and can create custom transformers to meet the most difficult specs. When you wire a current transformer, it is very important to make sure the secondary side is grounded and here are some reasons why.

Continue reading

Metering Vs. Protective Current Transformers

The wheels of industry are turned by some very large drive systems. However, some of the biggest machinery is controlled by much smaller control circuits. Current transformers help to keep these circuits running smoothly. Some CTs can effectively monitor current while others provide valuable protection. Here is a closer look at the differences and similarities of protective and metering current transformers.

Continue reading

Removing the Mystery from Current Transformer Classes

Current transformers are an important part of power transmission and control panel applications today. They have many ratings, and some can be customized to your business. However, there are letters and numbers printed on current transformers, and it is important to know what they mean. This brief explanation can help you get a better understanding of the subject.

Continue reading

Common Applications for Current Transformers

Current transformers play an important role in industry today. In fact, they are just as important as potential transformers because they can monitor and detect current flow in a wide range of circuits. There are many uses for CTs, and they can be found in many applications.

Continue reading

Specifications And Use Of Current Transformers For Power Circuits

At Midwest Current Transformer, we specialize in the manufacturing of standard and fully customized current transformers for power circuits. Our products are used to drop down the voltage or current in power circuits to be at a level that can be safely used by measuring equipment.

Continue reading

The Steps To Choosing The Right Current Transformer

There are many different factors to keep in mind when choosing a current transformer for any application. As this can be confusing and there is a lot of information out there that is not accurate, and this can lead to installing the wrong current transformer and having to replace equipment.

To make sure this does not happen, the first step is to contact the current transformer manufacturer if you have any questions or doubts about compatibility. The team at Midwest Current Transformer is here to answer your questions and to ensure that you are using the right product. Talking to our team when ordering current transformers allows you to have the right equipment for the job to avoid any last minute decisions and possible confusion.

Type of System

With any type of meter or power system, it is important to choose a current transformer that is designed for that system. This is particularly important with meters, as not all are uniformly designed. Another way to put this is that the metering or the protection required by the system is matched with the type of current transformer.

It is also important to know the primary range of the current transformer and to make sure this is compatible with the application. The various configurations of the primary and secondary windings provide this type of compatibility.

Accuracy Required

For current transformers that are used for measurement purposes, the degree of accuracy is essential. Not all current transformers offer high accuracy, and the more specific the requirement is, the more important the quality of the data measurement offered through the CT.

Continue reading

Lithium Ion Batteries: Cause or Victim?

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

Continue reading

The Case of the Dog Food Stealing, Fire Starting Mouse

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

Continue reading

Welcome William M. Granat, C.F.I.

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

Continue reading

Welcome Thomas D. Pruitt, C.F.I.

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

We at Blaze Fire Investigation are very proud to introduce one of our newest Fire Investigators, Thomas D. Pruitt, C.F.I.  Mr. Pruitt is an extremely qualified Fire Investigator with over 29 years of experience with the Danville Fire Department in Danville, Illinois; he currently serves as the Battalion Chief and Assistant Chief.

Mr. Pruitt is active in the Fire Investigation community and can frequently be found speaking, training and teaching about Emergency Response to first responders. He also participates in seminars that discuss the latest techniques and tools available for Fire and Explosion Investigation.

Mr. Pruitt attended Parkland Community College and Danville Area Community College, studying Fire Service Technology and Criminal Law.  His continuing education and training run the full gamut of topics concerned with Fire Investigation, Fire Service, and Hazardous Materials. 

Mr. Pruitt’s experience, education, and training make him an exceptional Fire Investigator and a fantastic addition to our team at Blaze Fire Investigation.

What is hidden in that piece of char?

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

Utilizing Radiography and Computerized Tomography as Tools for Non-Destructive Examinations

Many times the evidence left after a fire is unrecognizable and appliances that are made partially out of plastic have melted leaving only a pile of char.  However, most of the time, the metal components inside the appliance have remained intact and are just buried in charred plastic making them inaccessible for physical examination.  This causes a problem for the investigator because the components they need to exam are unavailable.  They risk causing damage to the artifact if they physically try to remove the components by breaking away the plastic.  That’s why our team of investigators are trained to utilize radiography (X-rays) and computerized tomography (CT scans) as a non-destructive examination tool.

Utilizing X-rays as a non-destructive tool has been used in fire investigation for years.  X-rays are a great way to see components on a two dimensional image and can be very useful in determining switch positions, fuse conditions, and many other things. A CT scan is an x-ray procedure that combines many X-ray images together, with the aid of a computer, to produce a three-dimensional image.  Below are examples of images from a CT scan of a surge protector.  As you can see, these images are incredibly detailed.


These images give our investigators the ability to see inside of an object without cutting or destroying the evidence and therefore preserving the evidence.   You can see the metal oxide varistors (MOVs) and switch contacts in the images above.  These tools are invaluable when determining the origin and cause of a fire. Contact Blaze Fire Investigation to assign a project or to learn more about our fire investigation and forensic engineering services.

Continue reading

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. 

Continue reading

Space heaters, use with caution!

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

Space heaters today come in many sizes and varieties.  Models range from small electric units that can plug into an outlet similar to an air freshener, to larger sized units that operate on fuel gas and heat larger areas such as a garage or workshop.  Space heaters can be a safe way to heat an area when used properly, but can become deadly when used improperly.  The US consumer product safety commission estimates that 25,000 fires a year are associated with the use of space heaters.

Space heaters can operate using convection or radiant heating methods.  Convection heating means the heater circulates warm air to heat a space. This type of heater is dependent on a working fan and good ventilation to distribute the heat and keep the housing cool.  Space heaters using radiant heat emit infrared radiation to heat up nearby objects and areas.  They do not contain a fan or blow air. 

Space heaters are heating appliances and like many other appliances, they have a life expectancy.  Space heaters should be replaced periodically, to ensure they contain the latest safety features and are in good working order.  Newer model space heaters have many built in safety features including a tilt or tip over switch that will shut the unit off if the unit is tilted past a specific angle.  Overheating protection devices will shut the unit off if the internal components reach a dangerous internal temperature.  Because space heaters do produce heat, the consequences of a failed space heater might be more significant than the consequences of a failed radio for example.  Using an old rusty space heater with a cloth covered power cord that was found at a garage sale might not be the best choice for your home.

Safe practices for space heater use:

Continue reading