In some states an officer of the company and often the president of the company must be a PE for the company to be an engineering company. These same states do not allow a company to use the word "engineering" unless this is so.
I recall a state holding Bell South liable because some of their...
David,
The study was done on the second worst polluted city in the world using the same methods the US EPA uses to study air quality.
The study shows that dispite the poor air quality the number of deaths from the poor air quality is not significant.
The US EPA study (2009) of US cities shows...
For a different perspective see the attachment.
http://files.engineering.com/getfile.aspx?folder=5e4345c9-0aee-467e-b2a2-c2f9dc6f258e&file=ehp-1-1103671.pdf
The university I graduated from was known as an engineering school. Out of a class of 450; 350 were engineers.
Since I graduated the number of graduates has risen to 700+. The number of engineers graduating has dropped to 21. I understand from my business partner that the same thing has...
TGS4
The data BEST is using is very suspect. The BEST study uses data
from earth stations that produced flawed data.
see: http://www.surfacestations.org/
I visited the two sites near me (<50 miles). Both sites were compromised. Each station was near an exhaust fan. The pictures were added to...
ITSMOKED & SKOGSGURRA;
In the US "shop guys" are trained to use PPE and
the proper techniques for use of a scope on 480.
My BAD if 1lostsoul is not from US.
1lostsoul:
The size of the VFDs you described are sufficient to
generate enough HD to cause your problem. If you are not trained to...
How many and what size are the VFDs?
Use scope to look at 480VAC. Sine wave should be "clean";
no dips at 90, 270, only one cross at 0, 180, 360.
Be sure to look at all three phases. The newer VFDs have
filter to reduce HD, BUT.. a lot of newer VFDs on same
feed will produce HD that can get...