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Knowledge Base
UPS System
UPS TECHNOLOGIES EXPLAINED
What's the difference, and which technology is right for you?
There a three different types of UPS: Off-line, Line-Interactive and On-Line. all suitable for different tasks, and supporting different types of load. To choose the UPS that is right for you, first determine the level of power protection that you need. Then match those needs to the appropriate UPS. Here are explanations of the different technologies, along with their advantages and disadvantages. Hopefully it will help you decide which type of UPS is suitable for you:
Offline - Standby UPS Technology
During normal operation, the power flows straight through the unit and hence only RFI filtering is usually provided. When the input voltage fails or fluctuates outside of a pre-set tolerance window, the UPS detects this and a relay will close, allowing the UPS to start feeding battery power via the inverter. The inverter is then switched on and either a square, step or sinewave form output is supplied. Upon the return of mains power, the output is switched back onto mains and the inverter is turned off. Typically there will be a break of between 4-10 ms during the transfer to and from the battery mode.
OUTDOOR ''UPS'' TECHNOLOGY EXPLAINED
When a UPS system is placed outdoors, it should have some specific features that guarantee that it can tolerate weather with a 'minimal to none' effect on performance. Factors such as temperature, humidity, rain, and snow among others should have been considered by the manufacturer when designing an outdoor UPS system. Operating temperature ranges for outdoor UPS systems could be around -40°C to +55°C.
An outdoor UPS system is normally made of several components designed for this particular task:
Outdoor enclosure: provides protection against the elements to all the components placed within. Quality outdoor enclosures are powder coat finished for corrosion resistance and long life. Outdoor enclosures are normally NEMA 3R compliant
WHY USE UPS?
An uninterruptable power supply (UPS) protects IT equipment and other electrical loads from problems that can affect the public electricity supply. It performs the following three basic functions:
- Prevents hardware damage typically caused by surges and spikes. Many UPS models continually condition incoming power as well.
- Prevents data loss and corruption. Without a UPS, data stored on devices that are subjected to a hard system shutdown may become corrupted or even lost completely. In conjunction with power management software, a UPS can facilitate a graceful system shutdown.
- Provides availability for networks and other applications while preventing downtime. UPSs can also be paired with generators in order to give the generators sufficient time to power up in the event of a power cut.
UPS TOPOLOGIES FOR DIFFERENT NEEDS
Three common UPS topologies described below provide varying degrees of protection for your equipment.
Passive standby topology (off-line)
is the most frequently used UPS topology for protecting PCs against power failure, power sag and power surge. In normal mode, the UPS supplies power to the application directly from the mains, filtered but without active conversion. The battery is charged from the mains. In the event of a power cut or fluctuation, the UPS delivers stable power from the battery. The advantages of this topology are low cost and adequacy for office environments. Passive standby topology is not suitable if the power supply is of low quality (industrial sites) or subject to frequent disruptions.Line interactive topology
is used for protecting enterprise networks and IT applications against power failure, power sag, power surge, undervoltage and overvoltage. In normal mode, the device is controlled by a microprocessor that monitors the quality of the supply and reacts to fluctuations. A voltage compensation circuit is enabled to boost or reduce the supply voltage to compensate for the fluctuations. The main advantage of this topology is that it enables compensation of under and overvoltage without using the batteries.
Guide to professional “UPS” selection
Selecting the correct size ups system is not as hard as you might think. However, it is vitally important because an undersized ups will not function when the power goes out. Here's how. UPS systems are rated by their Volt Amp (VA) and Watt output capability. For example, a ups may be rated at 3000VA / 2700 Watt.
The difference in VA and Watts is due to an electrical property called a power factor, but if you size the ups using Watts, you don’t need to worry about the power factor.
The Watt rating of a ups system is simply measure of how much equipment you can plug into it.
If you get a ups system that has a Watt rating that is too small, it will not provide the battery backup that you are counting on, or it may not work at all. Determining the size requirement for a ups is a pretty straightforward process.
The first thing to determine is the power requirement of your equipment. Most pieces of equipment have a tag on the back that will tell the watts or amps used, and the voltage.
Create a list of what you intend to plug into the ups system along with the watt requirement. The total of this list is your watt requirement.
Another factor to consider is whether you expect to be adding equipment in the future, or if your equipment growth will be pretty static.
Finally, always make sure you have at least 30 % extra capacity to ensure you battery backup will function when you need it. If you need more help configuring a ups system, please contact us.
Superior battery management
Battery service life is a major contributor to UPS reliability. Since batteries are electrochemical devices, their performance gradually decreases over time. Premature wear-out means higher costs in terms of replacement labour and shorter service cycle. A worn battery entails a risk of unexpected load loss. In normal UPS operation, backup power is needed only occasionally and the battery ‘wearing’ rate depends strongly on how the full charge is being maintained. Excess charging is detrimental under any operating circumstances.
Significant extension of battery life
Eaton has created ABMR technology to extend the life of valve regulated lead-acid batteries by applying sophisticated logic to the charging regime. Using the traditional trickle charge method, batteries become subject to electrode corrosion and electrolyte dry-out, especially in standby service use due to continuous float charging. ABM is essentially an addition of intelligence to the charging routine by preventing unnecessary charging, thus significantly retarding wear-out. ABM provides an additional feature for monitoring battery condition and advance warning about the end of battery life upon detection of a weak battery. It also optimizes the recharge time, which is advantageous when there may be consecutive power outages within a short period. ABM has been used for over 15 years is now applied in UPSs up to 1100 kW.
Hot Sync Technology
The internal output impedance of a UPS is inherently mainly inductive, i.e. it looks as a small inductor in series with a stiff alternating voltage source. So, if there is any difference between the output voltage phases, it means that there is a power flow from unit to unit, resulting in unequal load sharing. In the Figure 3, two units have equal output voltages with phase angle displacement.
The voltage Vdiff and current Idiff between units exhibit a 90 degrees phase shift due to the inductive source impedance. The main voltage (V1 and V2) and the current between units Idiff are in phase resulting in active power flow.
The greater the phase shift, the heavier the power imbalance. If we now introduce a controller to adjust the voltage phase by the output power, the phase difference can be forced to decrease. To adjust the phase difference to zero and to achieve accurate load sharing, we may integrate the measured phase thus arriving at power-controlled frequency. For the purpose of fast frequency locking and to enable synchronization to external bypass, a term containing the power level change rate is added.
AC - DC capacitors & Fans should be replaced?
While most all UPS system users are aware of the fact that the batteries, they use for backup power wear out, they are not necessarily aware of the fact that these same UPS also utilize large banks of capacitors as well. These capacitors are used in both the DC (electrolytic capacitors) and AC (polymeric film capacitors) sections of the UPS for filtering. These capacitors age and degrade and need to be replaced before they reach failure mode. Equally critical to the safe, long term operation of the system is the planned replacement of installed DC capacitors, AC filter capacitor assemblies and cooling fans.
UPS & BATTERY SERVICE MAINTENANCE PACKAGES
Komax specializes in service maintenance programs to keep your emergency and back-up power supply systems operating at full efficiency. We understand that it is critical for your power protection systems to be carefully maintained and operational. Power protection systems are designed to provide your power supply when the main support systems or utility power fail, so regular, thorough testing and maintenance of the systems are required to ensure that they will work when they are needed most. In addition, Komax is under exclusive contracts for many manufacturers to provide service and repair to their customers. Our maintenance services provide a single-point solution to your power equipment maintenance requirements. Komax offers service agreements that can be tailored to meet your company's specific needs. Our service agreements are managed by our professional sales and support staff.
- Maintenance agreements – Maintenance agreements with adjustable response times and different care levels are available. Contract discount pricing applies to all agreement types and plans. Preventative maintenance visits are included in all maintenance agreement types.
- On-site service – On-site service provides convenient, prompt service and repairs for your equipment.
- Preventative maintenance – Periodic preventative maintenance visits are included in the maintenance agreements, including options for annual, bi-annual, or quarterly visits.
- Battery replacement programs – Enhancing standard or full service agreements to provide different battery replacement options, from 10 to 100%.
- Battery maintenance – Maintenance options for batteries, with semi-annual, quarterly and monthly preventative maintenance are available to ensure long life for your back-up battery systems.
- Remote system monitoring – Remote monitoring services to monitor battery life, runtime availability and the integrity of UPS and DC power equipment ensure that your systems are operating at peak effectiveness.
- Consulting – Our sales and support staff will work with you to recommend the most effective maintenance and service agreements for your equipment.
KOMAX RECOMMENDED UPS SERVICE PLAN:
We recommend 2-4 preventive maintenance (PM) visits per year based on the critical nature of the application, site visit, and customer specifications. If four visits are determined to be required, two of these visits will mainly address battery conditions, while the other two will address both battery conditions and the uninterruptible power supply (UPS) operation. Battery and UPS operational maintenance conducted at the same time is considered a “major” PM visit, while battery only inspections are considered a “minor” PM visit. Battery only PM visit will incorporate a minor inspection of the UPS as described in the section Titled “Scope of Work”.
Major PM Visits will require that the UPS be put into “bypass” and isolated so the UPS can be safely inspected including its internal components. See UPS below.
STANDARD WARRANTY TERMS & CONDITIONS for UPS & BATTERIES
KOMAX GENERAL TRADING & CONTRACTING CO.
does hereby warrant that the UPS & Batteries will be free from defects in spare parts & workmanship from the date of Installation. Any defects or deficiencies that occur within the warranty period will be repaired or replaced, as needed and in a manner, at no cost to the client.
Warranty Termination:
- All warranty obligations are terminated when the UPS is operated outside specification and/or the published Komax operating instructions
- All warranty obligations are terminated when a customer or their sub-contractor or associated company makes any modification to the UPS that has not been recorded on a case by case basis with Komax and approved by the technical department
- All warranty obligations may be terminated should site or load or third party supplied UPS accessories be found on inspection by Komax to be damaging the UPS or causing operation that could reduce its working life
UPS SYSTEMS WITH LITHIUM-ION BATTERIES
UPS Systems with Lithium-Ion Batteries can be the perfect choice for your three phase UPS. Lithium-ion batteries offer several advantages over traditional valve-regulated, lead acid batteries commonly used in UPSs today.
UPS Systems with Lithium-Ion Batteries Benefits
Normal battery voltages are 2.25 volts per cell or 13.5 volts DC for a “12” volt battery. Battery voltages under charge should be 13.5 volts on average for all batteries. After isolation, the open cell (non-charging state) should be slightly lower than 13.5. These readings are recorded and any discrepancies are noted. Depending on the size of the battery, the voltage will drop to 11 volts or so under load. All battery voltages under load are recorded.
Longer life expectancy:
Lithium-ion technology can double or triple battery service life, reducing the risks of downtime or load interruption during maintenance or replacement. Lithium-Ion batteries also offer up to 10X the cycle life of VRLA batteries.
More power in less space:
Lithium-ion batteries provide multiple times the energy and power density compared to VRLA. As a result, UPSs built with Li-ion batteries take up only about one-third the space of a VRLA-based solution that delivers the same power.
More forgiving in a wide range of temps:
Li-ion batteries can withstand a wider temperature range than VRLA batteries.
Reduced cooling requirements and costs :
The smaller footprint and wider temp range of lithium ion batteries can reduce the space needed in a battery room and increase the optimal operating temperature range.
Less weight :
Lithium-ion batteries offer at least a two-thirds reduction in weight, at least. That means customers have more flexibility in terms of where they install the systems and can often avoid costly building modifications.
Battery monitoring systems included:
Li-ion batteries always come with sophisticated battery monitoring systems (BMS) that provide a clear picture of battery runtime and health.
Frequently asked Questions (FAQ)?
What’s the difference between a surge protector and a UPS?
A surge protector provides just that—surge protection. In addition to surge protection, a UPS continually regulates incoming voltage and provides battery backup in the event of a power failure. You'll often see surge protectors plugged into a UPS for added surge protection and additional output receptacles.
How much capacity of a UPS should I use?
To allow for future expansion, we recommend that you install a UPS at approximately 75 percent capacity. In addition, the batteries degrade over time; by oversizing, you provide room for error.
How much UPS battery runtime do I need?
During an outage, you need enough battery runtime to gracefully shut down systems or switch to backup generators. You may add an optional external battery module (EBM) to increase runtime. For a UPS battery overview and factors affecting battery life, request a UPS Fundamentals Handbook.
How is battery runtime impacted if I reduce the load on the UPS?
There can be a significant increase in runtime. Generally speaking, a UPS that provides five minutes at full load will provide 15 minutes at half load.
My business is too small for protective measures. Do I really need a UPS?
Power problems are equal-opportunity threats. Your PCs, servers and network are just as critical to your business as a data center is to a large enterprise. Downtime is costly in terms of hardware and potential loss of goodwill, reputation and sales. Also add in the delays that inevitably occur when rebooting lockedup equipment, restoring damaged files and re-running processes that were interrupted. A sound power protection strategy is cost-effective insurance.