Electrical Contractor Bangalore

Calculating the Weight of metals

2008-07-04T21:43:00.000-07:00

I was working on a quotation involving Control and Relay panels when my client had some major issues with the fabrication rates.

I enquired my fabricator for the break -up of aluminium and steel components of the panel. He gave me certain rates and gave me a weight calculation assuming a certain weight per meter. I being an engineer could have calculated the weight myself knowing the density f aluminium is 2.8 grams per cubic centimeter. Instead I worked upon a rate based on his calculations and faced some embarrassment in front of the client. And that too he is in the aluminium business so I cant claim ignorance and get away.

So for all the friends who need to calculate the amount of metal which goes into a making a product...

Take the size: eg: 100mm * 10 mm (width * thickness)
Take the length : eg: 3000mm (3 mtr long)
Metal : Aluminium
Density : 2.6- 2.8 grams per cubic cm

Now converting all to centimeters and multiplying as follows -
(100 mm* 10mm* 3000mm * 2.7gms/cm)
(10cm* 1cm* 300cm* 2.7gms/cm) / 1000
8100 / 1000
8.1 kg
We have considered 3000mm / 3 mtr so per meter we get 2.7 kg
100*10 flat of aluminium weighs 2.7kg per meter.

similarly,
Given the size and length of the materials needed, it is simple to calculate the total weight required.

I would warn you that a lot of websites, good ones, carry wrong information about the weights per cubic centimeter of well known metals/alloys. I would urge you to look into the information section of metals.org / have a engineering conversion table for steel and other materials.

Why is it important to know the weight?
Most of us who have bought steel or copper or any other metal will know that the dealer will be billing it to us in terms of the weight regardless of the quantity. And usually our clients will be given us rates for quantity rather than weight. So its very important for us to know the conversion between qty and weight.
Eg: ITEM SIZE UNITS QTY RATE TOTAL
Clients --> Copper 50*6 mtrs 10 1174 11740
Supplier--> Copper 50*6 Kgs 26.7 440 11748

Supposing our conversion was wrong and we had estimated the weight on the lesser side then, the supplier is safe because regardless of the weight per meter he will bill as per actual weight. The client is safe because we will bill him for length and does not care about the weight. So in case weight per meter increases the impact will be felt only by us. So its important to calculate carefully.

ISO Certification: New trend for Indian Cos

2008-06-24T02:37:00.000-07:00

With the growth in the Indian economy I observe there is a sudden increase in the number of companies which are getting certifications like the ISO 9001:2000 QMS (Quality management system) for their companies. This sudden change in trend and the sudden strife towards certifications, accreditation s and Quality prove that to become a globally competitive all companies must put in extra effort towards the Quality of their PRODUCT or SERVICE.
Although some organisations think certifications as a fad, which do not offer anything extra to the organisation in terms of operation, the trend is changing and more and more number of companies believe that these certifications will make them more competant, efficient, systematic and quality oriented.

"Choosing a Certification Body - http://www.iso.org "

Choosing a certification body

When choosing a certification body to carry out ISO 9001:2000 or ISO 14001:2004 certification, these are the aspects the organization needs to take into account.

The first point is that an organization can implement ISO 9001:2000 or ISO 14001:2004 without seeking certification. The best reason for wanting to implement the standards is to improve the efficiency and effectiveness of company operations. Certification of the management system is not an ISO 9001:2000 or ISO 14001:2004 requirement.
Deciding to have an independent audit of the system to confirm that it conforms to ISO 9001:2000 or ISO 14001:2004 is a decision to be taken on business grounds: for example
- if it is a contractual or regulatory requirement
- if it is a market requirement or to meet customer preferences
- if it falls within the context of a risk management programme
- or if the organization thinks it will motivate staff by setting a clear goal for the development of its management system.
Criteria to consider include:
evaluate several certification bodies
bear in mind that the cheapest might prove to be the most costly if its auditing is below standard, or if its certificate is not recognized by the organization's customers
establish whether the certification body has auditors with experience in the organization's sector of activity
establish whether the certification body implements, or is migrating to ISO/IEC 17021:2006, Conformity assessment – Requirements for bodies providing audit and certification of management systems
Another point to clarify is whether or not the certification body has been accredited and, if so, by whom. Accreditation, in simple terms, means that a certification body has been officially approved as competent to carry out certification in specified business sectors by a national accreditation body.

In most countries, accreditation is a choice, not an obligation and the fact that a certification body is not accredited does not, by itself, mean that it is not a reputable organization. For example, a certification body operating nationally in a highly specific sector might enjoy such a good reputation that it does not feel there is any advantage for it to go to the expense of being accredited. That said, many certification bodies choose to seek accreditation, even when it is not compulsory, in order to be able to demonstrate an independent confirmation of their competence.

The list of accreditation bodies with their contact information and links to their Web sites can be found on the Internet site of the International Accreditation Forum (www.iaf.nu), under "Members" > "Accreditation members". In general, accreditation bodies' Web sites contain an up-to-date list of certification bodies that they have accredited which can be used for selecting a certification body.

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The fee for applying for and ISO will be about INR 15,ooo/-.However if your organisation is not aware about the ISO 9001:2000 requirements then you will need to employ a consultant. The responsibility of the consultant will be to train the staff in the procedures set forth by the company, suggest improvements in the procedures being followed, conduct an internal audit along with the MR or Management Representative of the company so as to teach how to go about internal audits in the company. The consultants fee is based on the no of man hours required to train the company. Usually depends on the staff strength. For a company with 10 - 25 employees the consultants fee might be around INR 20,000/- to INR 30,000/-.

For more info :

http://www.iso.org

http://www.iaf.nu

Wind Energy

2008-06-16T01:12:00.000-07:00

If you have recently traveled to or passed Chitradurga , Gadag or Nargund in Karnataka on the Bangalore - Pune Highway you would have seen the numerous fans in the horizon spinning tirelessly. These are Windmills capable of generating anywhere between 250KW to 1MW.
1 KW is 1 unit which your local ESCOMs(Electricity Supply Compaies) bill you for. 250 KW machine is capable of generating 250 units of electricity every hour. Which means 6000 units every day assuming it runs for 24 hours.
Depending on the power purchase agreement with the KPTCL / other power transmission and distribution agencies you may get anywhere between INR.2.80/-(Two rupees and eighty paise) to INR.3.20/- (Three rupees and twenty paise) per unit.
Which means if your wind mill runs one entire day you will earn : 6000*3.2 = INR.19200/-
Per month 19200 * 30 = 576000
Per year 576000 * 12 = 6912000 (Sixty nine lakhs twelve thousand!!!)
Relax the companies which install these machines for you will guarantee about 30 percent efficiency which means 6912000 * 0.3 = 2073600/- per year.
Similarly a 800KW machine would fetch around INR.6635520/- per year. Also the companies guarantee the machine for 20 years and also give free maintenance for the first 8 years. So if you invest cash (not via loan) then return on investment will take nearly 5 years considering the depreciation benefits.

All said and done Wind energy isn't as attractive now as it was couple of years back. This is mainly due to change in policies, increase in bank interest rates both loan and deposit, current liquidity crunch in India etc..,

Lightning Arrestors: New technology

2008-06-12T01:28:00.000-07:00

Surge Protection

Image courtesy: SCHIRTEC Lightning Protection

Lightning protection is necessary to protect the buildings, bridges etc from lightning damage.

Lightning phenomenon is as shown in the picture. The charges in the air distribute,positive charges move up and negative charges collect at the bottom and the ground is considered to be neutral. The charges when strong enough result in lightning. Usually this discharge happens through tall buildings or trees and may result in damaging electrical appliances.

As shown there are two methods to provide
lightning protection to a building.

The mechanism is to provide a safe route for the charges to flow into the ground without affecting any of the electrical systems within the building.

more info on this new technology can be accessed from -
www.asci.in