Several large scale projects in India, due to lack of knowledge, propaganda by manufacturers/suppliers are being used in design and execution. This spoils the safety, quality, reliability and compliance of all known and recognised national/international practices.
One classic example is the use of Earthing in Metro rail projects. The following case study is from Chennai Metro rail Tender designed and published by M/S SYSTRA RAIL.
Unawareness of the Indian Standards, Misuse of the standards and regulations and propaganda by IEEE80 promoting software companies are the main reason for foolish and completely non compliant solution used in these metro railway projects. (Sorry to use these words as there are no better words to explain this illogical and nonscientific idea, insisted by a world renowned consultant for Chennai metro rail)
Refer the tender specifications and the calculations included in the above documents to understand the below figure. According to the calculations included in the tender by M/S SYSTRA MVA CONSULTING (INDIA) PVT.LTD, an earth fault in Low Voltage powerline (230 volt) produces a GPR of above 15kV. This illogical calculation is made, based on which two large earth mats are constructed under the metro railway station, one for LV electrical system and another for clean earth.
The system installed is not only meet the Indian standards but all standards mentioned in the tender. The tender specification looks like fancy sentences from several standards are included in it.
Video about the subject presented before 250 + participants can be viewed below.
In these metro rail projects tons of earth enhancing compounds are also used where the soil resistivity is about 30 ohm-M (highly corrosive soil).
This is a classic example of Believing IEEE 80 Propaganda software companies, operating in India.
All of these companies equally fail in informing the customer that
IEEE80 Guide is applicable for substation in USA (where the applicable voltages are different that what we believe in India),
IEEE Guides are documents in which alternative approaches to good practice are suggested but no clear cut recommendations are made in it.
IEEE 80 is educated as the Holy solution for all earthing problems in India, which leads to big mistakes in large projects of national interest.
For more information on various IEEE documents read IEEE SA - Standards Board Operations Manual – Clause 1
All together these software companies are spoiling the reputation of IEEE 80.
Some highlights from specification
1. In these metro railway projects, a grid as per IEEE 80 is constructed underground and is used for LV application.
Comment: This is ridiculous.
2. The soil resistivity mentioned is 30 ΩM. The earth electrodes are to be encased with earth enhancement material of 0.12 ΩM.
Comment: This enhancement material only increases the corrosion of the electrode. 30 ΩM itself is a very low resistivity and is highly corrosive in nature.
3. The drawings shows the conventional “TWO FOR NEUTRAL, TWO FOR BODY” is followed. This is either due to the unawareness of the designer or favoring some vendors.
Comment: The designer not only violate the standards mentioned in the tender but provide a wrong and bad impression about the standards.
Unfortunately, such wrong tender specifications once created will be followed in several projects, for decades without any scrutiny. Once installed, this system cannot be rectified again, which means the metro rail shall live with this junk for its lifetime. These installations survive due to mere luck rather than reliability.
As the first corrective step, all such tenders shall strictly follow IS standards, if not IEC standards as recommended in the current CEA safety regulations.
The above referred tender specification is a complete violation of safety regulations of Govt of India. Government shall have some mechanism to penalize the designers of these wrong designs and get compensation from them.
Another propaganda business by the American based companies are Arc flash study and Thermography and related safety measures as per NFPA70E in Low Voltage Installations.
Indian standard IS 732 is based on IEC 60364. Clause 6 of this standard explains verification (inspection and testing). These verifications are the fundamental requirement to ensure safety in the installation. Unfortunately in 99 % of industrial and commercial LV installations in India, the word electrical safety exist only in paper, (Means there is no actual safety measures recommended in IS732 implemented). More than 75 % electrical safety written rules in IS732 standards are unknown to the industry.
Remember in USA, the equivalent NEC (NFPA70) is mandatorily followed as a fundamental requirement. Requirements as per NFPA70 E is carried out to enhance safety (where fundamental safety is already ensured). This is the perfect method and a model which can be followed globally.
How ever in India, the companies in the business of NFPA 70, educate only the areas which is of their interest. As a result the fundamental requirements as per IS732 is neglected (rather unknown
Neglecting the Indian standards, which are often better than others, and running behind American, European and British standards is one serious factor spoiling our nationalism
Companies often do it protect their business interest, but we don’t understand why Indian consultants and contractors who doesn’t have any connection with international interest do this.
Electrical Safety in Industrial and Commercial premises in India will improve only if these propaganda business are understood well by the customers, start implementing the fundamental safety measures in Indian standards first.
Prepared and published by
S. Gopa Kumar
IEC - TC64: (Safety, Protection against shock) MT 3, MT 12, MT40, MT 41, PT 60364-8-3, WG 43
TC81: (Lightning protection) ahG 19, MT 3, MT 14, MT 21, WG 18
SC 37 A: (L V SPD’s) WG3 & WG
BIS - National Building Code-2016 (electrical committee),
ETD 20 (NEC, IS732, IS3043), ETD 30, ETD 50