—Mohan Nair, General Manager, 3M Electrical Markets Division
Global innovator 3M has several revolutionary products and services in the electrical equipment industry to meet the growing demands of the Indian power sector. We have here
Mohan Nair discussing two technologies with respect to the power T&D segment. First is the cold shrink technology for jointing of underground cables, and the second is the path-breaking ACCR conductor for efficient power transmission. Both the products are finding increasing acceptance in the Indian market, observes Nair. An interview by
Venugopal Pillai.
Tell us in brief about how 3M’s cold shrink technology for cables works.
We are pioneers and global leaders in cold shrink technology for underground cable network. The cold shrink technology offers high performance and ensures reliable connection to the cable networks. The major advantage offered by cold shrink technology of 3M over the traditional technology includes quick and easy installation; no requirements of special training; no flame, electricity or chemicals required for installation; it is safe for use in all hazardous environment; resists moisture, temperature, acid, alkali, ozone, sunlight and gasoline forms to any shape or size. Further since the installation does not require heating, it minimizes the danger of damage of the cable during the installation. 3M offers cold shrink solutions up to 66kV applications.
What are the distinct advantages of cold shrink technology over the more conventional hot shrink technology?
In the power cable accessories domain, we have developed and introduced cold shrink range of power cable accessories. This being cold applied technology, we do not use any fuel for installation and this is a big boon to many industries and power utilities. A typical Heat Shrink power cable accessory will consume 0.5 to 1 litre of kerosene/LPG per joint or termination during installation. It is estimated that approx 1 million heat shrink joints/terminations are being sold every year and if we take a conservative savings of 0.5litre/kit, then we can save approx 50 tonnes of fuel per annum.
Our products are future ready and can help to reduce fuel consumption, gain carbon credits and contribute towards environmental conservation. The cold shrink technology also reduces the hazards faced by the jointers (installers) on the field.
India still seems to be inclined to using the more traditional hot shrink technology. What are 3M’s plans in promoting cold shrink? How has the market for 3M cold shrink been ever since it was launched in 2008?
India is a very price-sensitive market with a host of local players with competitively priced products, which are predominantly heat shrink. We are a dominant player in power cable accessories segment and seen as quality supplier of power cable accessories with design capability. The corporation has invested in India looking at the growth opportunities. We will continue to invest and expand our operations over the coming years. We have been in the forefront of technology by offering newer and better products for cable jointing and termination applications over the past 40 years. We believe that investing and developing innovative products will help us expand our market share. The total cost of ownership using cold shrink accessory is far lesser than heat shrink technology.
We understand that industrial users (steel, cement, etc) have shown greater interest in 3M’s cold shrink, as compared with power utilities. What is your view?
It is very unfortunate due to price competitiveness; quality has taken a backseat for power cable accessories. This leads to poor performance and lower life of the cable systems.
Having said that, we are seeing an emerging trend in both power utilities and industrial end users who have given more thrust to such critical products; which ensures better performance and extends life of the cable system. For example, the cost of cable to cable accessory ratio is 95:5. The cable joint is a weak link in any power cable network; therefore it is prudent to invest in cable accessory to prevent any failure in the cable network, thereby ensuring uninterrupted power supply. 3M is advocating use of cold shrink technology which uses superior quality materials like silicone rubber, which gives better performance for the cable system and ease of installation.
India is beginning to be an emerging market for EHV cables. How do you rate the prospects for 3M cold shrink?
3M is a committed player in the electrical domain and have launched many products to meet the growing demands in this sector. We also offer EHV cable accessory up to 220kV applications. The EHV range of products is launched globally and the same are now available to the Indian customers.
Coming to power conductors, please elaborate on 3M’s ACCR conductors and explain its advantages over the conventional AAC and ACSR conductors.
The traditional overhead transmission conductors such as aluminum conductor steel reinforced (ACSR) are composed of a core made of steel wires stranded together and then covered with aluminum wires. The steel core carries the mechanical load of the conductor while the aluminum outer wires carry the electrical current. Modern transmission conductor such as the 3M aluminum conductor composite reinforced (ACCR) replaces the core steel wires with alumina fibre wires infused with high purity aluminum and the aluminum outer wires are a high temperature aluminum zirconium alloy, producing a lighter conductor than conventional ACSR conductors, but with the same strength.
Also, when energy flows through a conductor, it gets heated up and expands, causing the conductor to sag. But ACCR sags by about half as much as standard ACSR and can withstand temperatures as high as 240°C with no damage or loss of performance. The combination of high strength, low weight and low sag; allows twice the current to flow through it even while maintaining clearance and performance at high temperatures and over long periods of time. So existing transmission lines can be upgraded using existing structures and minimize disruption to existing facilities. On the whole the total cost of ownership for a utility is significantly less using ACCR compared to ACSR
We understand that a big deployment of 3M ACCR was for a project by Tata Power in Mumbai in 2010. Have there been more instances of late?
Yes, Tata Power, Mumbai, needed to upgrade two transmission lines. The population density is approximately 27,000 people per sq km as a result of which the company needed to upgrade their 110kV Borivali-Malad and Salsette-Saki transmission lines. To further complicate the issue, two-storey residences had sprung up under the lines severely violating the sag levels. Tata Power was looking for a solution that would survive Mumbai heat and heavy monsoons making the conductor’s reliability under harsh environmental and operating conditions essential. 3M ACCR was an automatic choice and the installation was completed using existing structures and without displacing people living nearby. The line capacity was increased from 900 to 1800 amps. These are long gestation time projects and we have completed two phases for Tata Power in Mumbai. We are also working on few more proposals in the pipeline.
Where does 3M produce ACCR conductors?
3M ACCR is the result of extensive technical development and years of testing in laboratories and in the field. This product is widely accepted across the globe and we have been receiving repeat business from all the customers worldwide like USA, Brazil, Russia, China, France, Canada, Germany, India, among others. The conductors are manufactured many at our facility in the United States of America.