|As we have stated previously, we are going to be taking the ideas developed in this column over the last couple of years and developing them into design practices. This is how it works. We will provide the basic narrative here for one design practice each week. We will keep it open for comments for one month. After that, we will finish it in formal form and offer it for sale at a modest price. Here is where you come in. If you make a substantive contribution to a standard, the organization for which you work will be granted a pro bono license to use that standard with its current issue number for as long as you like. We have had good response so far! Contribute, please.|
This week's: High Voltage Systems (LGM 2013.008.01 when issued)
Copper, without doubt, is the most expensive material by weight in a pulp and paper mill. In common electrical equipment such as HV cables, bus-bars and transformers, the copper value accounts for up to 80% of the total price. The rising cost of copper requires industry to find new ways to reduce the quantity of copper or replace with other materials of similar characteristics.
Raising the motive voltage in electrical systems reduces copper cabling sizes. Modern systems are designed to use approximately half the copper of the old 480 volt systems, and step down transformer systems will be simpler, too.
In new mills, there is no excuse for not using high voltage systems for large power consumers.
In older mills, a program should be initiated to replace high KW motors with high voltage motors on a separate circuit. Eventually you'll be able to scrap the old cabling at a handsome profit and enjoy the benefits of a modern system.
The use of high voltage systems to reduce copper quantities in the pulp and paper mill.
So, give us your comments by 26 March 13, please!
High voltage systems minimize the quantity of copper required in bus-bars and motor windings, and reduce the sizes of copper conducting power cables.
Higher voltages for electric motors should be selected during the design phase. During layout, reducing the distance between electrical distribution switchboards/motor control centers can reduce the number of cables as well as the size of the copper conductors. There is also a reduction of power losses in transmission lines.
The use of higher voltage systems can lead to a slight increase in the cost of insulation,
however this is off-set by the significant cost reductions associated with the use of less copper.
Still open for comments: FRP Tanks (Open until 19 March 13)
Still open for comments: PVC Air Piping (Open until 12 March 13)
Still open for comments Lightweight aggregate concrete (Open until 5 March 13)
As always, your comments will be appreciated.
Brian Brogdon, Ph.D.
Send us your comments!