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Issue of May 2003 
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Cover Story: Power Conditioning
Does your power diet keep you fit?

The power conditions in different zones across the country differ, with some zones having a more stable and reliable supply. Here's a look at what companies in different zones have done to ensure that their IT infrastructure gets clean and consistent power supply. by Minu Sirsalewala


Honda Siel Cars

Honda Siel Cars a leading passenger car manufacturer has an extensive IT infrastructure to streamline its manufacturing processes and provide high quality products and services to its customers and partners.

Since all the manufacturing processes are completely automated and IT dependent, a power failure in the IT setup would result in loss of revenues and data.

Hilal Khan, Head-IT, Honda Siel Cars says, "Power outage may affect us in two areas. One, to IT infrastructure and another to plant and machinery. Though we have diesel generators (DG) to feed the complete power requirements of the company, a specific process in automobile manufacturing (Weld Shop) cannot run on DG power. The direct impact of power outage is production loss."

Though the company is independent because of DGs, it has calculated the production loss to be around eight working days that the organization may face in absence of their own arrangement of power.

Honda Siel UPS Arrangement (Past & Present)
Click on images for larger view

Power requirements

The company does not follow any specific formula to calculate its power requirements.

"We simply know the kind of PCs, servers, and hardware devices we are using, and what we are going to use. The power requirements for such PCs (Voltage multiplied by ampere multiplied by number of devices), is a one time load. Every piece of equipment has its own power requirement and it helps us in the load calculation of the power. DG set load per day also helps us in calculating the current requirement for mission critical needs.

We know the future requirement of infrastructure based on plans and past growth rate, and therefore at the time of planning we keep the growth aspect in view," explained Hilal.

Power architecture

The power architecture for the unit is divided between IT infrastructure and Plant & Machinery. For IT the company uses normal power backed up by DG sets and UPS. In case of plant & machinery (production area) the company has normal power backed by DG sets.

"We have five DG sets of 1250 KVA each. In addition to this we have one 40 KVA online UPS, three 20 KVA UPS, three 10 KVA UPS, one 6 KVA UPS and around fifty 1 KVA and below, offline and line interactive UPS," said Hilal.

Source for power

Honda Siel uses one feed for power supply from the external agency, i.e. NPCL (Noida Power Company Limited), and three internal feeds i.e. normal power, DG set and UPS. According to Hilal Khan NPCL being a private company, the power situation is reasonably better than the rest of Uttar Pradesh.

He added, "We have a sanctioned load of 3000 KVA though our present load is only 1200-1500 KVA. It has upgrade and future potential of 7500 KVA. We are getting power from 33 KV distribution. We are drawing 2500 KVA by our own step down transformer to convert it to 440 Volts at 50 Hz, 3 Phase."

He further explained that there is provision in the current deployment for future growth. The provision could be related to additional load, additional space or any additional resource.

Power Conditioning Policy

Hilal Khan is of the opinion that power conditioning policy is need- based, plan-based, growth-based, and experience-based. Even in the absence of a documented policy their agreed agenda and objective is to have zero loss in terms of production, sales and overall business. And this is achieved given the comprehensive power management setup that they have in place.

Centralized UPS

The company feels the regular power availability (from NPCL) is reasonable though it is not at the desired level of requirement.

"Car production and car sales are our main line of business thus a total power backup system for production is in place. IT is an important tool to aid and run our business smoothly, thus we have a third source (apart from normal power backup, DG set and UPS backup) i.e. a centralized UPS," explained Hilal. The centralized UPS helps in power distribution for computers, laptops, printers and other hardware. He further added that numerous problems were associated with stand-alone UPS like breakdown at regular intervals, high maintenance cost, high repair time and user inconvenience. But the centralization of the administration block has made it easy to maintain and manage the UPS. The high costs that were incurred to repair stand-alone UPS are eliminated. Downtime has been considerably reduced.


Dabur India Limited, one of the largest FMCG companies in India, is located in a geography where power outages are routine. Dabur uses technology in a big way to integrate a vast distribution system spread across the country. Dabur is adequately supported by multiple power sources to keep the IT infrastructure running.

Power requirements

The power requirements of the company are calculated by summing up the vendor's recommended rating for the equipment.

Power architecture

Dabur has an in-house generator capacity for 100 percent load in case of an outage. Power failures could occur several times a day and more often in summers.

Gopal Shukla, CIO, Dabur said, "There are UPS systems in place that maintain continuity during switch-overs. The critical servers have up to three sources of redundant power supplies." On the hardware side the company has over 100 UPS systems of different makes.

Power source

There are multiple feeds that supply power to the unit. Gopal Shukla explained, "The heavy-duty generators can run the entire electrical load on a continued basis. These are redundant and back each other on a vendor recommended duty-cycle."

The company banks heavily on the in-house power generation that is capable of handling the entire electrical load on a continued basis.


Sify Data center (Vashi)

A data center requires 100 percent uptime given the nature of its business. The loss faced by the center in case of power outage is enormous and immeasurable. "A power outage at a data center results in loss of data, failure of communication links, discontinuation of services, end of physical security services, loss of revenue and loss of faith in business from customers," opined Somenath Ghose, General Manager, Sify Limited. He also explained that repeated power failures could result in malfunctioning of hardware components and subsequently bring the business operations to a halt. Maintaining 100 percent power uptime to avoid power outages is paramount to IT infrastructure companies. To align with its business needs Sify Limited has invested heavily in building their power layout for their Level 3 Internet Data Center at the Vashi Infotech Park, Navi Mumbai.

Power requirements

The data center's total power requirement for IT infrastructure includes lighting load, power load, and air-conditioning load. Power load is sum total of power requirement for network/communication equipment, desk-tops, servers, EAPBX, access control system, CCTV surveillance system, and fire alarm/monitoring systems. Ghose said, "We add up the power requirements of each and every system, hardware components, lighting load and air-conditioning load to arrive at the total power requirement of an IT infrastructure."

Power architecture

The data center has two feeds for power supply. It has a 2N redundant power network that includes transformers, generators, HT/LT distribution, cables, UPS units, all in multiples of two, to ascertain that there is no single point of failure.

The hardware at the data center includes generators, online UPS, capacitor banks, dedicated earthing, lightening arresters, and surge protectors for providing total power solution.

The generators support power load and air-conditioning load. The online UPS (with battery backup) feeds power load including power to hardware, network equipment, servers, desktops, storage devices, communication equipment, EAPBX, security systems and fire panels. Every hardware component is fed by two different UPS power sources. Capacitor banks take care of reactive load. Surge protectors and lightening arresters are installed to protect from surges and lightening strokes respectively. Body earthing, neutral earthing, UPS dedicated earthing, and earthing to communication equipment are separately provided to ensure proper grounding of electrical equipment.

Source of power

The Sify data center uses two feeds from power supply providers in the form of ring mains supply.

"The basic power infrastructure is built with proper cabling size and distribution units considering the total connected load and future load requirement to the maximum," said Somenath. As the center's power layout is duplicated, power components like UPS, generator, feeders, and others can be added as and when the load increases by switching off one circuit where addition is required and keeping the other circuit live at the same time.

Power Conditioning Policy

The data center has a well-documented power conditioning policy. The Policy guidelines include:

a) Ensure all electrical components meet IS/IEC standards during and post installation.

b) Monitor incoming power parameters—from service pro-viders—like voltage, frequency, and power factor current in each phase on a regular basis and take corrective action immediately if we find irregularities.

c) Monitor and regulate UPS output parameters like voltage, frequency, power factor, current and generator parameters like speed, voltage, and frequency in each phase. And do the necessary corrections by making adjustment as and when there are changes beyond set limits.

d) Carry out regular preventive maintenance of power equipment to ensure all devices are in good working condition. Carry out insulation test to ensure cable and distribution bus-bar has strong insulation between phases & neutral and between phases & earth. Carry out earth pit megger test to ensure electrical equipment is grounded properly.

e) Conduct power audits once in six months to check transient voltage, harmonic levels, noise, waveform distortion, and frequency variation and make necessary corrections. Check actual vs. defined current levels in the cable & bus-bar to ensure there is no overload situations.

f) Ensure pure and clean output power to the equipment, which is not affected by sags, surges, spikes, noise, harmonics, low/high frequency and power outages.

Power availability

According to Somenath, power is available most of the time and power outage in Mumbai city is minimum.

The data center addresses the power outage issue through the following preventive steps:

  • Determine the length of the usual outage.
  • Determine outage history for the facility.
  • Have backup generators available—purchased and leased through a generator supplier open 24 hours a day—as a last resort.
  • Ensure adequate fuel storage facilities.
  • Protect critical applications with UPS systems backed-up with generators.
  • Determine load transfer sequence, the most critical loads should be transferred to standby power first.
  • Make sure electrical staff are trained to connect backup generation to existing electrical system.
  • Test operation on 'no load'
    regularly and 'on load' at least once in a week.
  • Train key electricians on all operational phases of load transfer and emergency generator operation.
  • Arrange for backup fuel for generators if the outage last longer than expected. Maintain battery, radiator water, fuel level, and oil level on regular basis. Keep necessary spares in stock.
  • Maintain a current list of telephone numbers including local utility provider and the DG vendor.


NSE's Data Center power architecture

The NSE (National Stock Exchange) data center at Bandra-Kurla complex in Mumbai, houses the IT infrastructure and all the critical data that keeps this stock exchange running. The business of the exchange totally depends on IT and any power outage would severely affect the IT infrastructure resulting in loss of revenue for the exchange.

C. Kajwadkar, Vice President, NSE.IT Limited said, "The loss would run into a few crore of rupees per day on account of loss of revenue for the exchange, banks and depositories, apart from loss of productivity of our own staff." To avoid any kind of downtime due to power failure NSE has assessed its power requirements and has a reliable power architecture in place.

Power requirements

C. Kajwadkar said, "Power requirements for the IT infrastructure are assessed based on the advance planning during the inception stages of building the IT infrastructure. This would include power requirement of all servers, PCs, and network equipment. The same is reviewed at least once a year for necessary actions if any."

For IT equipment: The center has drawn an estimate model for the load based on the actual consumption as per equipment datasheets, adding a factor of safety for the recommendations and provision for future demands including the required back-up time. Based on this, broad specifications of the UPS requirements are drawn; back-up capacity is factored upon which the battery capacities are worked out. A spare capacity of at least 40 percent extra is normally provided for future expansion. To ensure availability of power under an acute outage spanning more than the battery back-up time, redundant DG sets of desired capacity are also put in place.

For environmental equipment: Air-conditioning requirements for the above equipment/data center is computed using standard methods such as BTU computation, temperature to be retained, etc. This load is also factored in the overall power requirements.

For lighting and other miscellaneous load: Other requirement for equipment such as Access control devices, physical security system (CCTV), Building Automation Systems etc has been factored in.

It is ensured that utility power requirements such as illumination and elevators have been taken care by the respective departments within the organization.

C. Kajwadkar explained, "We design for at least 40 percent extra capacity in the UPS that also provides for future augmentation, which is reviewed at least once a year. And for AC power supply, the power supply company has provided sufficient capacity cables, which will cater to 100 percent growth in future. We have a provision to install more number of equipment at the UPS and Stabilizer level."

Power architecture

The architecture at the center is based on multiple layer redundancies, which start from the redundancies provided by the power supply distribution company to the power provided to all the IT equipment. The choice of a service provider is based on the type of power generated at power stations such as hydro, thermal, etc.

The center has opted for power supply from a company that offers both thermal as well as hydro-power coming to a receiving station through which the power is distributed. Redundant feeders on LT power (440 volts) at the sub-station feed the AC power to its distribution panels. The status of each feeder is remotely monitored by the SCADA system installed by the power company to monitor the status of the supply from the receiving station control room, which is located about six kilometers from the site.

Multiple diesel generators have been installed to mitigate the risk of failure of supply from the electric company. UPS systems with adequate battery backup are deployed. The UPS design is based on redundant modules that feed clean and stable power to the load in a parallel fashion. For e.g. the load on each of the modules does not exceed 30-31 percent to ensure continued operation under a critical scenario in which even two out of the three modules fail. Additionally, there are stabilizers that continue to feed the critical IT systems in case of failure of the entire UPS.

Power source

At equipment level, the power is fed from two different power sources—the electricity company and captive diesel generators—with redundancy in power supply modules for all equipment as a policy. Apart from building redundancy in the UPS itself, separate UPS are maintained for data center and users across various floors.

Power Conditioning Policy

C. Kajwadkar said, "We have factored for power conditioning at the initial planning and design stages. Factors such as total harmonic distortion (THD), harmonic suppression, power factor, and built-in filters take care of continued and smooth power output. The desired parameters are measured at desired intervals under the Service Level Agreement (SLA). The policy also takes care of support on 24X7X365 basis."

Power availability

Power supply in Mumbai city has been very good and the center has not faced any disruptions even when there was a complete grid failure last year (2002). Kajwadkar also added that the power supply company's system has a well-designed islanding system which operated successfully and separated itself from the rest of the Maharashtra grid.


Bank of Muscat, Bangalore

Bank of Muscat, based in Bangalore, depends heavily on technology for its banking operations. So losses due to power failure are bound to be very high; any kind of power failure will cause total impairment of banking operations.

Ravishanker N, Head-IT, Bank of Muscat said, "All ATMs including offsite ATMs rely heavily on the network and any outage will result in the ATMs being down because of network issues. An offsite ATM cannot function without communicating to the central server."

In monetary terms the bank will lose large amounts if it is not able to remit within a particular timeframe. This makes it imperative for the bank to address the issue of power supply to its IT infrastructure, to ensure uninterrupted banking operations.

Power requirements

The bank's power requirements depend on the type of hardware to be deployed. "We usually go by the ratings given in the product catalogue. As we need to add 30 percent of the original requirement to handle contingency," explained Ravishanker.

Power architecture

The bank has classified its power requirements as critical and non-critical. The data center and few desktops have been identified as critical. The architecture also constitutes of separate UPS with a hot standby to avoid any single point of failure. The bank has standardized its hardware on Tata Liebert.

The increase in power requirements is taken into consideration at the project level, and a contingency of at least 30 percent is provisioned for while deploying the solution.

Power source

The bank has one power feed supplied by the State Electricity Board. It does not have a specific power conditioning policy, but has a scheduled quarterly Preventive Maintenance for the bank and all ATMs.

"Bangalore faces high power cuts thus the bank has installed DG sets to counter the situation. The entire set-up has to be manned for 24x7x365 days for any anomaly as the entire operation is dependent on the availability of the setup," says Ravishanker.

Minu Sirsalewala can be reached at

Ring mains supply:
Currently the Sify data center has two incoming sources of power from MSEB (Maharashtra State Electricity Board). One power source comes in from Vashi grid (New Mumbai) and the second from Sanpada grid (New Mumbai). The two sources are connected in the form of a ring having high-tension breakers in between. In the future, more power sources can be added to the existing ring as and when the need arises.
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