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The year was 1997 , when Tata liebert engineers visited us at an exhibition at world trade centre. They were looking for something that could protect their online UPS in harsh Indian conditions. Their attempts to use stabilizer has not resulted good results. The UPS was high frequency technology relatively new at that time and Tata leibert had ushered it to India from Chinese OEM in hopes to revolutionise the UPS industry with sleek models. The UPS was was more efficient in conversion of power as it had no transformer in it. All of this work was done with help of passive components.
However little did they know that they were in for a nasty surprise. the tolerance of these UPS was about 20% where as voltage fluctuations in India is more than 35%. At times trees would fall on overhead wire causing damage. Weak neutral or disconnection of neutral due to irregularities in distribution was very common. All this contributed to defect ratio of more than 26%. which would mean that 1 out of 4 UPS would come back for repair. This is bad statistic for any product. They were on verge of discontinuing the product line as it seriously dented the image of then no.2 company in online UPS.
After use of OVCD, their defect ratio went down from 26% to 6% which was a huge improvement. hence they decided to make it standard product for each UPS that would be sold in India.
Many of distributors till date don’t know the exact use of OVCD, except for reason that it is supplied along with UPS and that it was mandatory to install it if they hoped for free servicing under warranty.
OVCD is protection device which safegaurds then equipment against damage caused by extreme overvotlage due to abnormal situations such as
1. neutral open condition
2. double phasing
Why should you consider using OVCD before your equipment?
1.No problems due to voltage fluctuation.
3.Your equipment becomes more rugged
4.Less service calls = Increased profitability + Increased credibility.
5.Better perception of quality of your system in the minds of the customers
6.Increases the chances of repeat sales or referral sales.
Now you can install your equipment in the worst electrical conditions without being bothered about service calls.
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For bulk requirement we offer special rates
Our appliances are getting smarter by the day. Its a good thing that many companies are energy conscious and are making their appliance even more energy efficient. In India most of home appliance are now made compulsory to have 5 star energy ratings, especially cooling appliances like ACs , refrigerators.
The TV ads are now flooded with ads talking about inverter based ACs, refrigerators. This is great news for energy conservation. However there is rider to all this. These units are susceptible to damages because of power fluctuations.
A traditional circuit consisted of a step down transformer which converted 230V AC to 24V AC which was then fed to bridge rectifier. The rectifier then converted the AC to DC and then it was distributed to the internal circuits with regulator and other component. Even if the voltage increased dramatically the secondary side would experience a relatively low surge on voltage. Prolonged exposure to voltages might have caused damages to internal circuits. In short these circuits were relatively very sturdy in voltage fluctuations.
However transformer has losses. It dissipates a lot of energy in the form of heat. Even in best cases the efficiency possibly didn’t not go beyond 87%, which was problem. Transfomer is bulky. Higher powered (kVA) machines would require a bigger transformer and as result were heavy too.
What we call inverter technology today , consist of PWM inverters and SMPS based circuits, may be even more advanced. These units have done away with conventional transformer based circuit and in effect increased the efficiency. They are also light weight , very compact and dissipate less energy as heat. They also come in attractive housings
However the flip side is that these circuits are now directly exposed to raw power. This is where the new problems have come up. These circuits are having 20% tolerance to voltage fluctuations. This would mean 180V on lower side and 280V on higher side. Seems ok doesn’t it? Wrong!!!
In developing and underdeveloped countries the power conditions are not so good and voltage frequently goes beyond 350V. This is a curse for these inverter based appliances, which get damaged more frequently than their predecessors.
These circuits are not inherently designed for such conditions and since units are manufactured considering global markets which include EU and US. Many white goods brands have made their foray in a new market only to have marred their reputation by service issues. We have many brands making their disappearing act after blitzkrieg of sales and ads.
One can attribute a serious contribution of such factors on making and breaking of brand in Indian conditions. There is probably two options here, either improve the tolerance of the internal circuits or protect the units externally by use of some protection equipment.
Do let us know what you think.
Author: Amit Manjrekar
(Click the image to learn more about him.)
Over voltage problems are the most frequent the most overlooked and neglected. Many times equipment failure, downtime, software and data corruption, are the result of a problematic supply of power. There is also a common problem with describing power problems in a standard way. We have tried to list out some of the common facts about over voltage issues
- Overvoltage, and its destructive effects, are well known but are often not recognized or understood.
- Little is documented in terms of its magnitude and frequency.
- It is difficult to identify, due to its sporadic nature, and often comes and goes undetected.
- Because of all the above, its existence is sometimes denied.
- Equipment failures due to overvoltage are often misperceived as defective equipment.
- Power companies do not deny its existence; but they do not publish or otherwise inform the users that it exists, or warn users of potential periods in which it may occur.
- Power fluctuations are also caused due to in–line equipment. Viz. Motor during its starting period draws heavy current due to which voltage drops causing imbalance and over voltage somewhere else.
- With very few exceptions, electrical power distribution systems are inadequate to provide voltage within acceptable limits to all users at all times.
- Power companies cannot prevent overvoltage because they can only react to its existence, usually in response to customer (user) complaints about failing appliances, etc.
- The time of response can vary widely (anywhere between one minute and weeks) depending on many variables in the distribution system.
- Overvoltage can occur at any time, due to many factors, but is most likely to occur during certain periods such as fast changing high load demands, as seen during severe cold weather periods.
- Power companies are mandated by law to provide service without overvoltage.
- Power companies are not held accountable by any regulation authority for overvoltage.
- Power companies will sometimes reimburse damage costs due to overvoltage if proof is provided by the complainant.
- Overvoltage can only be proved by the use of a voltage recorder.
- Some power companies offer overvoltage insurance to users.
- Over voltage events are misperceived to be equipment failures leading to their replacement with other brands that do not have overvoltage protection and essentially mask the effects of overvoltage which can lead to inevitable catastrophic failures.
- OVCD- Over Voltage Cut-off Device
- How does a Servo Controlled Voltage Stabilizer work?
- Product breakdown management
- Protect your Equipment from harmful power fluctuations..
- Give reliability to your UPS systems in high fluctuation areas. OVCD solves your servicing woes!!!
- Protect your electronics
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