The role of voltage regulators in backup systemsBy Afam Nnaji on 12/09/2009
Views: 1500 | Comments: 0Every single electronic or electrical appliance is manufactured and expected to perform based on certain assumptions. One of the assumptions is that the input voltage would be a certain voltage for example Europe and Africa settle for 220V while the USA is ok with 110V.
The utility provider like PHCN in our case under normal circumstances delivers 220V at 50Hz frequency but under abnormal circumstances can send over 300V to your house or office and when this happens chances are that some of your electrical/electronics products would just go bad.
Voltage regulators or stabilizers as we know them and as their names imply are designed and built to help keep the voltage to a safe voltage - 220V in this case.
Put differently, for you to enjoy reliable and safe electricity in your home or office PHCN must deliver the 220V needed and any voltage regulator used must handle the input voltages from PHCN and deliver a stable 220V.
From the on going, PHCN can deliver over 300V or can deliver as low as 150V under abnormal conditions. For you to make use of electricity under these conditions the voltage regulator must guarantee a stable 220V output within its operating limits.
What this means is that a voltage regulator is setup to handle a range of voltages within which it can provide a steady output and outside which nothing is guaranteed.
Now, when using an inverter backup system you also need to guarantee that the input voltage is a stable 220V and your best option is to look for a voltage regulator.
So, under ideal conditions any voltage related problem or abnormality is supposed to be handled by voltage regulators, right? Wrong. The reasons are
1. The voltage regulator cannot do anything outside the designed range for example 170V to 280V or 220V +/- 10%.
2. A lot of voltage regulators in the market today are sub standard or simply unreliable to the extent that even as an alternative energy consultant and as an inverter builder I have not recommended any voltage regulator for any client for over 2 years now.
Unfortunately, there is no functional consumer protection agency in Nigeria that I know of. If there is one then Nigerians need to know their rights and obligations as regards seeking redress when faced with sub standard products or defective products as the standard practice of the seller or the manufacturer telling you that nothing can be done even if the product in question is less than 6 hrs in use is totally unacceptable and should be checked.
Those who have installed one form of power backup system or the other tend to get more confused as the failure of a backup system may result in different vendors trading blames and as usual will never accept responsibility of their actions or inactions but would rather blame the other party at all cost even when facts on the ground prove otherwise.
A recent experience with 2 different clients using exactly the same configuration of inverters I built for them serves as a good example and learning point for both service providers and clients.
Client A lives in Lagos and got his inverter built and installed over 6 months ago. Just 3 months into the usage of the inverter backup system he called that the unit wasn't working. A technician was sent to his place and he found out that a lot of damage was done. Unit was retrieved, cause of problem suspected to be very high voltage which meant the voltage regulator either wasn't working well or that the voltage PHCN delivered was outside the operating window of the voltage regulator. As is common with our warranty promise we repaired the unit an no cost to the client while making him understand that the problem was a PHCN/Voltage regulator limited problem. This was also done to encourage people to rely on inverter backup systems as they are not only cost effective but reliable. Unit was returned and the voltage regulator replaced as per our advice.
6 months later (that is 3 months after the initial problem) I got a call from the same client that he was informed while he was in his office that PHCN was giving a very high voltage to his own neighborhood and that when he returned the house was without power which shouldn't be considering the fact that his inverter was an automatic one so would have switched to battery backup immediately regular power went off unless of course the high voltage must have done some damage again. He proceeded to switch on the generator and heard a sound and quickly switched it off and then decided to call me.
As usual someone was sent to the place to take a look at the inverter which was later retrieved and considering the fact that this was another PHCN related issue I explained to the client why I will not repair the unit without his paying for it because PHCN or voltage regulator issue cannot be made an inverter issue. Over 40 minutes of talk on the phone he insisted it had to be the inverter since he bought the stabilizer just 3 months ago and as such could not be responsible. He requested that the unit be returned without repairs if I would not undertake the repairs at my cost and I obliged him and asked my people to reassemble the unit the way it was when it was retrieved and paid about 30% of the cost of repairs just for the work done on the unit and had the unit sent back, unrepaired.
My position was based on purely professional conduct as I made it clear that what I owe a paying client is a reliable product backed with 1 year warranty on the unit which I have been doing for over 5 years now but would not succumb to any cheap blackmail when the problem is a PHCN or voltage regulator related one.
Now, compare the above to client B who had to send down his own unit just 24 hrs after installation as the unit went bad immediately he connected a voltage regulator he just bought brand new.
I also took time to explain to the client the problem with a lot of voltage regulators out there and asked him to send the unit down which he did.
The unit was repaired at no cost to the client B and sent back to him in Abuja. We later agreed to forget about the voltage regulator (even though that meant taking a risk with PHCN) since according to him the problem with the inverter unit came up the moment the voltage regulator was introduced to the inverter system.
The system was reconnected and everything started working fine. He then asked his electrician to test the stabilizer and the result of the test was shocking. He stated the stabilizer was providing a very high output voltage and burnt a charger that was connected to it during the test. Now, this voltage regulator was bought brand new and does not even work right from the carton/package. In fact, the voltage regulator in this case actually takes in a steady voltage from PHCN and delivers a much higher voltage when it should be doing the opposite.
The client was very honest and appreciated our discussion while we hope that PHCN will not deliver dangerously high voltage until a good voltage regulator is brought into the inverter system equation.
A tale of 2 clients with same inverter backup system and same voltage regulator problem but with different position and conclusion.
A different setup for a different client saw the voltage regulator just pack up under 2 days and at that time luckily for us the damage to the inverter was very minimal.
Now, one begins to query the role of Standards Organization of Nigeria (SON) as regards the quality of these units. There is no reason why people who manufacture or sell these units should not be made to make full refunds or offer free repairs for such units if they are defective or come with manufacturer fault.
This is not to give any cover to any end user abuse as one cannot rule that out.
May be Nigerians would need to take the bull by the horn and begin to take legal actions against manufacturers and sellers that cannot refund or repair electrical or electronics products if they are sub standard or just pack up for no reasons at all.
Today, it is common to hear Nigerians say that inverters really don't work especially when such people may have used one or two inverters whether locally manufactured or imported.
This is a shame because we have people using inverter backup systems for years in Nigeria. The last time I used a generator in my office was over 5 years here in Lagos and the inverter was built by us with components that are found in typical electrical shops here in Nigeria.
The technology behind a voltage regulator is not complex at all so I wonder why those who manufacture these voltage regulators cannot do this right. From wrong topology to wrong implementation of a good topology and to cheap and/or sub standard components the story is the same and yet Nigerians spend their hard earned money to buy these units without any framework to protect them when things go wrong.
Personally, whenever I want to buy anything especially electronics or electrical appliance I ask the seller how sure he/she is and if the warranty is enforceable as he/she will not like me when I come back with a defective product and he/she begins to speak grammar to me. Usually, on hearing this the person disappears for some seconds or minutes and comes back with another version of the same product but of course with a higher price tag. When I ask why he/she didn't bring this one before I hear excuses like "Nigerians don't like buying them because they say they are more expensive" or that "People prefer the cheaper ones due to cost".
I have voltage regulators that are over 10 years in active service but the irony of the whole thing is that even the same brands of these voltage regulators in the recent past even when bought brand new have been giving problems to some people so you find it very difficult to even recommend any brand.
No comments yet. Be the first to post one.
You must be logged in to post comment. Login or signup.