Sunday, February 20, 2011

Can your wiring system handle the Digital world?


Although the Computer has been hailed as a modern day miracle machine it brings with it some unfortunate consequences that should be the concern of every Fire Official.
Which is the creation of Harmonics in Power Lines supplying power to modern electronic equipment such as computers, calculators, Energy Saving Light Ballast's
The reason for Harmonics being generated is because many of today's modern electronic
equipment are using Non Linear type power supplies, which
causes disturbances across the power lines to the point that it can destroy breaker panels and transformers through excessive heating of the non current carrying neutral wire ,and even causing fires. when 60 cycle 120 volt Alternating Current is observed on an Oscilloscope you normally see 2 reversed half circles with clean lines on the scope but when harmonics are present this same smooth wave now takes on flat topping and zigzagging characteristics
Non Linear supplies are used instead of Linear supplies because of the cost ,with linear supplies running 2 to 3 times the cost of a non linear unit
Many times Harmonics are missed as the reason for electrical malfunctions and the malfunction is attributed to other reasons. Or the electrical contractor or Inspector may not be fully trained and aware of Harmonics and there danger.
Harmonics are found in buildings using 120 /208/240 volt and 277/480 volt 3 phase 4 wire services which are found in large commercial areas and many large Apartment Buildings
and can be identified by looking at the incoming overhead service wires one should see 1- un-insulated neutral wire and 3 insulated hot wires. or by reading the wiring plates on underground service transformers Harmonic damage to buildings is only going to increase with computer usage and buildings built over 10 years ago especially very old office buildings which have not had there services upgraded to prevent Harmonics, can be an on going danger to occupants .Plus
Fire Companies will see an ever rising amount of emergency responses for Electrical
Conditions and fires.
So what should fire Officials be looking for to alert building owners they may have a Harmonics so they can have it corrected to prevent a future catastrophe.

1# melted neutral or ground bars in breaker panels and transformers.
2# Excessive over heating of step down transformers found with in the building
3# Frequent motor overheating and burnout
4# Frequent overheating of Fluorescent light Ballast's.
5# excessive heat on breaker panels and switch gear
6# an increase of Fire Station responses involving Electrical conditions to the property

Remember the above items does not always mean there's harmonics present
but if the building uses many electronic items then Harmonics may be the culprit .
and there could be a serious electrical fire or malfunction your company may
need to respond to some time in the future which could be prevented with proper repairs.

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