A guide on how to select the most suitable power protection system at an affordable price.
Power Protection systems can be challenging and at times frustrating to choose, especially if an organization or individual isn't familiar with their needs. Overengineering can result in high costs. If a system doesn't take into account all of their power problems or consider local resources, they can so easily waste money. - It is essential that those unfamiliar with the selection process:
- Be aware of their own needs
- Ask potential suppliers the right questions
- Understand the strengths and weaknesses of different design approaches
Our advice and guidance on ten of the most frequently asked questions will help you choose the most appropriate and cost-efficient solution.
1. WHY IS POWER QUALITY IMPORTANT?
Electrical systems need high-quality power to function properly, so their performance is not impaired or their life expectancy is not compromised. When electrical devices or loads lack the necessary power, they may malfunction, fail prematurely or not function at all. Electric power can be of poor quality in many ways, and many causes of such poor quality exist.
2. IDENTIFYING PROBLEMS IN THE MAIN SUPPLY
Identifying exactly the problems first is always recommended in order to find the best solution. The purpose of monitoring the power supply over time is to determine the types, duration, and magnitude of power problems. There are several sources of power supply problems, including distribution network problems, switchovers, weather conditions, heavy equipment or faulty hardware. In any case, the resulting power quality issue will include at least one of the power problems.
3. DETERMINING THE POWER SIZING OF THE EQUIPMENT THAT NEEDS PROTECTION
It is important to check the rating of the equipment being protected. These ratings are normaly given in the form of amperes or kVA and whether they are single phase or three phase. As with three phase, you'll need to know the nominal line to neutral voltage and line to line voltage, plus the frequency and power factor. It is usually indicated on the rating plate attached to the equipment or you can contact the manufacturers. The RMS value of the load can also be taken instead. It is important to factor in possible expansion of the load over the medium and long-term when determining the total power rating. Check list:
- Are you aware of your own requirements?
- Are you aware of the right questions to ask a potential supplier?
- Are you familiar with the advantages and disadvantages of the various types of design?
4. WHAT IS THE BEST SOLUTION?
The best way to identify clearly the most cost-effective and best-suited solution lies in knowing the type of mains problems an organization/individual is experiencing and the power requirements of the equipment they wish to protect. The obvious choice will be an online UPS (Uninterruptible Power Supply) if a customer experiences all of the Power Quality problems identified in Question 2. However, these are usually costly to purchase and have high ongoing maintenance costs.
It is often difficult and expensive to find the high technology skills required to maintain such systems in less developed countries. Where the loss of mains is not a pressing concern or can be addressed by using a standby generator, installing an automatic voltage stabilizer or AC power conditioner is a more cost-effective solution, both from the point of view of initial cost and of expertise needed to install, maintain and support it.
5. DIFFERENCE BETWEEN A VOLTAGE STABILIZER AND POWER CONDITIONER?
Voltage stabilizers and AC power conditioners differ in many ways. Both protect against transients, spikes, sags, and brownouts. However, an AC Power Conditioner also offers further protection against electrical noise and a higher level of protection against spikes and transients. Power line conditioners (AC Power conditioners) are usually just voltage stabilizers with the addition of isolation transformers. The 'Common Mode' Noise (E to L and E to N) problem could occur. Power Conditioners can suppress this interference with the use of shielded isolating transformers. One common term for the output of an AC Power Conditioner is the clean supply. It is common for AC Power Conditioners to cost more than Voltage Stabilizers/Regulators.
6. DETERMINING THE INPUT VOLTAGE VARIATION AND OUTPUT VOLTAGE ACCURACY
You need to select a stabilizer whose input range can be varied, otherwise its output will increase by the same amount that its input has gone "out of the limit." If the mains supply is good, a stabilizer offering a variation swing of + 15% is more than sufficient. A stabilizer may need to accommodate variations of + 20% or greater in remote locations or in countries with less developed national infrastructure. The more input voltage swings the stabilizer / conditioner has to correct, the more expensive it will be. A Voltage Stabilizer should have an output voltage of at least 1% greater than the preset output voltage. In contrast, if the load equipment can tolerate a lower output voltage, then the input voltage range can be extended accordingly. Due to the cost of the stabilizer being correlated with its input voltage range, it may be more cost-effective to accept a lower output accuracy.
7. IS SUPPLY FREQUENCY IMPORTANT?
Since most mains supplies operate at 50 or 60 Hz, the frequency is likely to vary no more than 3%, which most stabilizers can handle. However, if the power is supplied by a local generator, it is possible that the frequency may deviate outside of this range, and both the load and the power protection system need to be protected.
8. OTHER FACTORS TO CONSIDER WHEN CHOOSING A VOLTAGE STABILIZER
Input Output Circuit Breaker: Specifying an input or output circuit breaker that, in addition to providing over current protection, will trip in the event of an output or input deviating above or below a preset level is recommended. In some of our models, input circuit breakers are standard, while on others they are available as an option.
Bypass Facility: A bypass switch lets you inspect and maintain the stabilizer by isolating it from the load and connecting it directly to the mains supply. Inbuilt or wall-mounted external switches can be provided as required.
9. ADVANTAGES OF SERVO VOLTAGE STABILIZERS
Our reliable and economical servo voltage stabilizer
is proven solution for voltage stabilization, accommodating input voltage swings of more than 40% and delivering an output accuracy of 1% for the majority of applications. It consists of a transformer with its secondary winding connected between a power supply and the load; its primary voltage is automatically controlled by a motor-driven variable transformer that delivers a constant, smooth, and very stable voltage. High voltage spikes / transient spikes are typically controlled by surge suppressors. Suppressors of this type limit transient voltages to twice the peak voltage of the supply. That way, spikes are reduced to levels that are totally harmless. This feature comes standard with the Vener7 SVS solutions.
In electronic servo stabilizers, the design has proven to be very reliable and can be easily maintained by anyone with a basic level of ability. Servo voltage stabilizers are economical solutions for broad applications in industry, mining, aerospace, commerce and telecommunications due to their long lifespan, compact size, and low ownership costs.
- A size and weight advantage over other stabilization methods
- Fast response time to voltage changes- ideal for most applications
- Very competitively priced
- Nil output waveform distortion
- Not Frequency dependent
- Attenuates voltage spikes if necessary
- Unaffected by changes in load or power factor
- Low ownership costs and ease of maintenance
- Durable and long-lasting
- Minimal maintenance required for moving parts
- Response time is slower than for solid-state designs