The Ultimate 10-Step Guide To Choosing A Voltage Regulator (Buyer’s Checklist Included)
11 Jan 2021
Est Reading time: 11 minutes
Choosing the perfect Automatic Voltage Regulator (AVR) can be a confusing process for some. Whether you’re a facility manager, an electrical designer or even a consultant, selecting the perfect brand and type of AVR could be one of the most crucial factors in the success of your project.
This step-by-step guide is purposefully designed to ensure you have checked all the boxes in your buying journey, with considerations of your requirements, budget, pro tips of technical specifications to watch out for, and more…
Below is a road map that will take you one step closer to your electrical project goals.
Now let’s get you started.
Bonus: Read to the end to get a comprehensive checklist, created to help you find the best Automatic Voltage Regulator that suits your operational needs.
As some electrical challenges (in both industrial and commercial applications) are more complex than others, you can create your goals accordingly to match them.
If you’re looking for detailed resources for solutions to solve specific electrical problems like severe voltage fluctuations or voltage drops, get a copy of your complimentary whitepapers here (full 22-page reports packed with quantitative and qualitative research).
Depending on how drastic the load change in your operations are, inherent voltage fluctuations cause voltage levels to be low during the day (high load) and extremely high in the night (low load). A wider input voltage range might require an AVR voltage tolerance of up to ±40%, so your equipment continuously enjoys an optimised and stabilised output voltage supply. After all, the goal is for your high value loads to receive total voltage protection, no matter how erratic the input voltage can be.
Some common designs include:
- Servo Electronic – Time tested design, high voltage accuracy, most widely used in both industrial & commercial applications, best value for money.
- Magnetic Induction – Uncompromising durability and dependability, high in manufacturing costs but ideal for rugged use and harsh environments.
- Static (Tap Switching) – Suitable for non-critical applications, quick to build, cheaper cost.
- Solid State (Ferroresonant) – Highly reliable (no moving parts), ideal for single phase application.
For an in-depth overview of the different types of AVR designs, this blog article provides diagrams and illustrations that highlight all the features and benefits to help you easily understand the working principle of an automatic voltage stabiliser.
Beware of products that cut corners by using recycled copper wires to lower the price. As time goes by, these products will very soon cost more to use and maintain (due to low efficiency and high maintenance) or even worse, fail prematurely. For a list of key players in the market, here’s a Yahoo! News Report highlighting a list of recommended Key Players in the AVR market.
Any burning questions?
No worries, here’s a bonus FAQ section just for you.
Frequently Asked Questions
A: There are 4 commonly used types of Automatic Voltage Regulator (AVR) designed for commercial and industrial applications:
- Servo Electronic
- Magnetic Induction
- Static (Tap Switching)
- Solid State (Ferroresonant)
Each design has its pros and cons. While Servo Electronic based Voltage Stabilisers have mainly dominated the market, the ever-growing demand for uncompromising reliability and maximum durability in voltage protection has caused an unsurprising shift towards the Magnetic Induction design.
Static tap switching design (thyristor based) is favoured by non-critical projects that are desperately constrained by budgets. When technical specifications are written under non-stringent requirements (e.g. voltage output of ±10%), cheaper prices may be preferred over quality.
Solid State Design (ferroresonant) is highly dependable. With no moving parts, the ferroresonant voltage stabiliser is not subject to mechanical wear and tear. Due to its nature, it is typically suitable for single phase applications.
To learn more on which design is ideal for your application, read our comprehensive blog article (11min read) to find out more.
A: An Automatic Voltage Regulator is designed to maintain the output voltage stabilised, from no-load to full, regardless of load change. Whether the input voltage is low during the daytime (due to high load), and high in the night (due to low load), the AVR continuously and automatically regulates – future proofing against facility expansions. In other words, your output voltage will remain constant regardless of load change.
A: It depends on which power system you’re using. If your load is on a single phase system, use a single phase Automatic Voltage Regulator. Single phase volt units are in use with a single phase power system, which is common in many homes.
However, if you’re using a three-phase load, or want to regulate a three-phase power system, use a three-phase Automatic Voltage Regulator.
A: Automatic Voltage Regulators are designed and built typically with input voltage tolerance from ±10% up to ±40% (of the set output voltage).
For example in a 3-phase system:
Your minimum input voltage: 348V
Your maximum input voltage: 444V
Your set output voltage: 400V
The optimum choice of protection would be an AVR with ±15% input voltage tolerance because it effectively maintains a stable output voltage for fluctuating input voltages between 340V and 460V.
Depending on your operations, if the bigger the required input voltage tolerance, the higher the cost of the AVR will be. Hence, it is essential to find the perfect balance between effectiveness and price.
A: Regulator sizing is based on the maximum load, with a small amount for future expansion (10% to 25% extra) and some derating for certain occasions. The buyer’s checklist below will assist you in making a decision of what size of AVR is the best option for your operations.
Pro tip: If you’re powering a single equipment with high inrush current, like a wielder or a X-ray, choose a regulator with a rating higher than the equipment’s full load rating (e.g. 30% to 50% extra). Take note of the rated voltage, frequency, number of phases and current or KVA, which can be found on the equipment’s nameplate or manufacturer’s catalog.
When in doubt, contact the equipment’s manufacturer if you’re planning to use an AVR for a single system which consists of equipments such as a CAT scanner or X-ray apparatus.
Q: Why should I go for a Voltage Regulator when there are other cheaper and viable options out there?
A: What is guaranteed to work best for you should be an option that meets your requirements, your budget and operations. It also has to be a solution which meets your goals.
Pro tip: If your goal is to ensure power backup, certainly an Automatic Voltage Regulator isn’t going to solve your problem. Instead what you should be looking for is an Uninterruptible Power Supply (UPS). If you’re looking for voltage protection for sensitive electronics and communication equipment, an ideal solution will be an AC Power Line Conditioner. And finally if your goal is to eliminate voltage drop or simply comply with voltage drop limits, the optimal solution will be a Voltage Drop Compensator
In conclusion, now that you’re well equipped with these 10 Steps to consider before purchasing your Automatic Voltage Regulator, we hope that this article has given you the clarity and insights to help you in your journey to hugely improving your uptime.
And even if you’re simply doing your comparison shopping, feel free to Download this AVR Buyer’s Checklist as your guide to find the most ideal voltage solution for your needs.
Have you decided on the best AVR for your needs? 😉
P.S. Need more professional advice? Contact us to get your complimentary consultation, where we systematically review your requirements and provide you with a customised solution to your needs. If our 40 years of experience in the Automatic Voltage Regulator market has taught us anything, we’ve found that the best solution – is always one that’s both on point and on budget.