Latest Generators/UPS Articles

High Efficiency UPS Systems deliver double-conversion protection, low THD, high power factor, intelligent battery management for data centers, ensuring clean power, reduced losses, redundancy, advanced SNMP monitoring, and remote alerts.

What Are High Efficiency UPS Systems?

High Efficiency UPS Systems are UPS units that optimize conversion efficiency, power quality, and battery runtime.

✅ Double-conversion topology; low THD, >=0.9 power factor

✅ Modular N+1 redundancy; hot-swappable lithium-ion batteries

✅ SNMP/Modbus monitoring; advanced battery management

Energy efficiency for uninterruptible power supply (UPS) equipment is so important because they can influence UPS energy efficiency and can directly impact energy costs. This paper will compare the differences in energy efficiencies among various UPS topologies available today through laboratory testing. These studies demonstrate flywheel—based UPS technology achieves much higher efficiency ratings as compared to legacy battery based UPS systems, resulting in substantial cost savings over the life of the system. For context, understanding the basics of a UPS is essential, and resources like what is a UPS system explain core functions in more detail.

UPS systems provide power conditioning and backup power to mission critical facilities such as data centers, broadcast sites and hospitals. UPS systems protect these sites from voltage fluctuations such as surges and sags or frequency fluctuations and also provide ride-through or temporary power to bridge the gap between a power outage and the restoration of utility power or the transfer to a backup generator. The UPS uses a form of short-term (seconds to minutes) energy storage to assist in power conditioning and power bridging in the event of a complete outage. The most common and practical direct-current (DC) energy storage forms are chemical batteries (for example, lead acid, NiCd, and NiMH), flywheels and ultra-capacitors. To perform its two functions, a UPS requires energy—in this case electricity. For an overview of architectures and operating modes, see UPS uninterruptible power supply overview for context on how these elements interact.

The industry measures UPS efficiency as power out divided by power in with the UPS consuming a portion of the input power. The amount of energy consumed by the UPS represents energy lost or inefficiency. UPS inefficiency can waste 10 per cent or more of utility input within the UPS itself and is a significant concern for data center operators, utilities and policy makers. UPS inefficiency amounts to thousands of kilowatt hours per year wasted in the process of protecting even a medium-sized mission critical load. A deeper understanding of conversion stages and losses can be found in UPS power supply fundamentals that map components to typical efficiency impacts.

UPS EFFICIENCY DEFINED

The efficiency of a UPS, as defined by the International Electrotechnical Committee, is “the ratio of (active) output power to (active) input power under defined operating conditions,” where defined operating conditions refer to a specific per cent load and load type (linear/resistive versus non-linear). Active power is measured in watts or kilowatts. Manufacturers often publish UPS ratings and efficiency curves that help compare performance across load levels.

IMPORTANCE OF UPS EFFICIENCY

The power demands of data centers are significant and growing. The U.S. Environmental Protection Agency (EPA) estimated data centers consumed 61 billion kilowatt-hours (kWh) in 2006 at a total electricity cost of approximately $4.5 billion. The EPA’s baseline forecast predicts a near doubling of energy consumption by 2011 to more than 100 billion kWh and $7.4 billion, assuming current growth and efficiency trends (2). In its alternative forecast views, EPA identified adoption of higher efficiency UPS systems as a key factor in reducing data center power consumption (3). A study by Intel Corp. showed typical UPS systems as contributing six to seven per cent losses to overall data center energy use. Strategic placement, redundancy choices, and distribution design are covered in designing data center UPS infrastructure to align efficiency goals with reliability.

At the individual data center level, improving UPS system efficiency offers direct, 24-hour-a-day energy savings, both within the UPS itself and indirectly through lower heat loads and even reduced building transformer losses. When a full data center equipment load is served through a UPS system, even a small improvement in system efficiency can yield large annual cost savings. Pacific Gas & Electric (PG&E) estimates a 15,000 square-foot data center with IT equipment operating at 50 watt-per-square-foot requires 6.9 MWh (megawatt hour) of energy annually for the information-technology (IT) equipment. If the UPS system supplying that power has its efficiency improved by just five percentage points, the annual energy bill will be reduced by 384,000 kWh, or about $38,000 at $0.10 per kilowatt hour (kWh), plus significant additional savings from the reduced cooling load. Procurement teams can apply tips for selecting a UPS system to balance efficiency ratings with lifecycle service considerations.

COOLING REQUIREMENTS AS A FUNCTION OF EFFICIENCY

 When evaluating a UPS and its efficiency, it is important to keep in mind the first law of thermodynamics that “energy can neither be created nor destroyed.” With respect to UPS systems, the difference in active input and output power represents heat loss as a result of the activity the UPS performs. Heat interferes with the environmental conditions in a defined space such as an electrical room and will ultimately drive the temperature up and potentially cause short- or long-term damage to equipment as it exceeds designed temperature thresholds. A sound design of an electrical room includes an air-conditioning or precision cooling system to maintain a certain temperature band. The lower the efficiency of the UPS, the more heat that is generated and the more cooling that is required in the room, driving up capital costs and the ongoing operational expenses of the cooling system. As a general rule of thumb for an efficient centralized cooling plant, it takes 0.33 kW of power to cool one kilowatt of heat. As a result, the operational cost of a low efficiency UPS is further exacerbated by the additional cooling cost. Thermal performance features and maintenance guidelines in uninterruptible power supply best practices can further mitigate cooling overheads in dense rooms.

FACTORS IMPACTING UPS EFFICIENCY

There are two key factors influencing UPS system efficiency: the topology of the UPS system itself and the design of the data center’s power supply and distribution, which determines the load factor of the UPS.

UPS TOPOLOGY

The design of the UPS system itself has a significant impact on efficiency. Put simply, some UPS designs are inherently more efficient than others. There are two major topologies in use today in mission critical facilities—parallel online (also known as line interactive) and double conversion. 

From: Power Quality, Grounding & UPS Handbook, Vol 12, The Electricity Forum

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• Electrical Generators and UPS Channel

You need an emergency generator sized to your total wattage needs. Smaller units, ranging from 5 to 7 kW, cover essentials such as lights, refrigerators, and sump pumps, while units with 20–22 kW provide reliable whole-home backup, including HVAC systems.

What Size Emergency Generator Do I Need?

Refers to the process of calculating backup power capacity to match the energy demands of a household or business during outages.

✅ Determines generator size based on watts, circuits, and load

✅ Ensures appliances, HVAC, and lighting operate safely

✅ Prevents underpowered or oversized generator selection

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The first step in choosing a generator is calculating your total wattage requirements. Appliances and devices draw two types of power: running wattage, which keeps the equipment operating, and starting wattage, sometimes referred to as surge watts, which is required during startup. Motors, pumps, and compressors often demand two to three times their running watts to start. Identifying the highest starting load is critical to prevent overloading your generator. When considering emergency backup generator options, it is important to compare capacity, fuel type, and wattage requirements to ensure your unit can handle both essential and whole-home loads.

Running watts cover steady-state demand, while starting watts account for those momentary peaks. For example, a refrigerator might require 700 running watts but 2,200 starting watts. If you plan to run multiple appliances simultaneously, your generator must be sized to meet the total running watts plus the highest single starting wattage. Understanding the emergency power supply options available helps homeowners decide whether a portable, inverter, or standby generator best matches their outage risks.

Essential vs Whole-Home Backup

Many homeowners must choose between powering only essential appliances and covering the entire house. Essential circuits usually include lighting, refrigerators, sump pumps, medical devices, and communication equipment. A portable generator rated between 5,000 and 7,500 watts usually provides adequate backup power for these needs. For homes and facilities with sensitive electronics, pairing a generator with a battery backup system can extend runtime and protect against short interruptions.

For those seeking seamless operation during power outages, a home standby generator is often the most suitable solution. Whole-home units are permanently installed, connected through an automatic transfer switch, and can power air conditioners, electric stoves, and central heating systems. House generators in the 18- to 22-kW range are commonly used for whole-home backup, ensuring that air conditioning units and HVAC systems remain operational. Learning how does a generator work provides useful insight into why surge watts and starting loads play such an important role in choosing the right size.

Types of Emergency Generators

Different types of generators are available for both residential and commercial applications. Portable generators are mobile and fueled by gasoline or propane, offering versatility during short-term outages. Inverter generators deliver cleaner power for sensitive electronics, operate quietly, and can be paralleled for more capacity. Home standby generators are fixed installations that run on natural gas or propane, providing automatic protection without manual intervention.

When choosing a generator, consider whether you need portability, quiet operation, or a permanent, automated solution. Powerful generators may be ideal for critical facilities, while inverter generators are suitable for households prioritizing fuel efficiency and reduced noise. Exploring the electrical generators and UPS channel gives a broader view of technologies, ratings, and selection tips that can guide your generator sizing decision.

Fuel Considerations

Fuel type influences convenience, runtime, and maintenance. Portable units typically run on gasoline, though dual-fuel models also accept propane. Home standby generators commonly use natural gas supplied by a utility line or propane stored on-site. Natural gas provides an uninterrupted fuel supply and eliminates storage issues, but requires a sufficient supply line. Propane offers longer storage life and flexibility.

Air Conditioning and High-Demand Loads

Air conditioning units are often the deciding factor when choosing the right size generator. Central systems have compressors that require very high starting wattage. A 3-ton air conditioner can easily exceed 6,000 surge watts at startup. If cooling is optional, smaller window units may lower demand and allow downsizing. Carefully assessing the highest starting load ensures the generator can handle surge watts without stalling.

Choosing the Right Size Generator

To size a unit accurately, follow this process:

1. List all appliances you want powered during outages.

2. Record their running wattage.

3. Identify the appliance with the highest starting wattage.

4. Add total running watts plus the single highest starting wattage.

5. Select a generator that exceeds this figure, leaving a 20 percent safety margin.

This approach avoids undersizing, which risks tripping breakers, and oversizing, which increases cost and reduces efficiency. For critical applications such as data centers, designing data center UPS infrastructure demonstrates how generators and UPS systems work together to deliver reliable power continuity.

Emergency Generator Sizing Checklist

Practical Scenarios

An essential-only setup might include lights, a refrigerator, a sump pump, and a small air conditioning unit. Combined running wattage may reach 3,500 watts, with starting surges pushing requirements to 6,000 watts. In this case, portable generators or paired inverter generators can suffice.

A whole-home backup scenario, including a central air conditioner, electric water heater, and cooking appliances, could demand 18–22 kW. Here, a home standby generator fueled by natural gas is the most suitable option.

Maintenance and Reliability

Even the most powerful generators require maintenance. Portable models need regular oil changes, fuel stabilization, and safe storage. Home standby systems should be exercised monthly and serviced annually. Ensuring transfer switches are tested and circuits are balanced guarantees reliable performance when power outages strike.

The question of what size emergency generator I need is answered by calculating wattage requirements, balancing running watts with surge watts, and factoring in the highest starting load. Smaller portable units provide backup power for essential appliances, while whole-home standby systems fueled by natural gas or propane ensure uninterrupted comfort, including the operation of air conditioners and HVAC systems. By carefully selecting a generator, considering the fuel type, and planning for regular maintenance, you can achieve reliable protection against outages while avoiding the pitfalls of underpowered or oversized equipment.

Frequently Asked Questions

How do I size a generator for an air conditioner?

To size a generator for just your air conditioning unit, check the unit’s starting watts and running watts on the nameplate. Add at least 20 percent for surge protection. A central air conditioner usually requires a larger home standby generator, while a window unit may be supported by a portable or inverter generator.

What are surge, peak, and starting watts?

Surge watts, peak watts, and starting watts all describe the brief power spike needed when a motor-driven appliance starts. They are higher than running watts and critical for choosing the right size generator. If ignored, the generator can stall or overload.

Can a portable generator power my whole home?

A portable generator can power an entire home only if it has sufficient capacity and is connected to the home's electrical system through a transfer switch. Without this, backfeeding into utility lines is dangerous. For whole-home backup, most homeowners rely on a permanently installed standby generator.

Is natural gas better than propane for standby units?

Natural gas is convenient because it provides an unlimited supply and eliminates the need for storage, but it relies on an active utility line. Propane is stored on-site, lasts longer in storage, and offers flexibility during utility disruptions. The best choice depends on availability and risk of outages.

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An emergency generator provides backup power during outages, protecting critical loads in hospitals, data centers, and industrial facilities. It starts automatically to keep lights and systems on, improving safety, reliability, and resilience when utility power fails.

What is an Emergency Generator?

An emergency generator is a backup power source that activates during utility outages to maintain electricity for essential systems.

✅ Ensures continuous power for critical facilities like hospitals and data centers

✅ Operates automatically during grid failures or blackouts

✅ Improves safety, resilience, and operational reliability

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It provides essential backup power when the grid goes down, keeping critical systems online. Many standby generators operate on natural gas, offering a reliable fuel supply without the need for storage. Paired with an automatic transfer switch, these systems instantly detect outages and seamlessly shift electrical loads, ensuring safety, continuity, and resilience for homes, hospitals, and industrial facilities.

Unlike portable generators, emergency standby generators are permanently installed, integrated with electrical systems, and often governed by local building codes. Their design emphasizes resilience, rapid start-up, and continuous availability, making them indispensable in mission-critical applications. For situations where complete redundancy is required, an emergency backup generator provides continuous assurance against unexpected blackouts.

Why Use an Emergency Generator?

The primary purpose of an emergency standby power generator is to provide resilience against unexpected outages. Hospitals depend on them for life-support systems, airports for navigation equipment, and data centers for uninterrupted digital services. In manufacturing, downtime costs can reach thousands of dollars per minute, making backup power an economic necessity.

Beyond critical infrastructure, residential and commercial facilities also rely on standby generators to maintain comfort, security, and safety. Whether powering elevators, emergency lighting, or HVAC systems, these units guarantee continuity in ways battery storage alone often cannot. To understand regulatory requirements, visit our page on emergency power supply compliance, which outlines key standards such as NFPA 110 and CSA C282.

Fuel Types and Selection

Emergency generators typically run on diesel, natural gas, or propane. Diesel generators are widely used because of their durability and ability to handle large power loads. However, they require regular maintenance of stored fuel, which can degrade over time. Natural gas units, in contrast, connect directly to municipal gas lines, providing a continuous supply without the need for refuelling.

Propane generators are favored in remote or rural areas where natural gas is unavailable. Dual-fuel systems are gaining popularity due to their flexibility, which allows them to switch between diesel and natural gas to ensure operational reliability. Each fuel type comes with trade-offs in terms of cost, availability, storage, and environmental impact, making selection a crucial part of system design.

• Diesel – High power capacity, durable, but requires on-site fuel storage and maintenance

• Natural Gas – Continuous supply through utility pipelines, cleaner burning, but dependent on gas line availability

• Propane – Good for remote areas, stable storage, but higher cost and limited tank capacity

• Dual-Fuel Systems – Combine diesel and natural gas for resilience, flexibility, and extended runtime

Many facilities pair emergency standby power generators with battery backup systems to cover the critical seconds before generators fully engage.

Fuel Type Comparison Table

Transfer Switch and Power Transfer

At the heart of any emergency standby power generator system is the automatic transfer switch (ATS). This device monitors the utility supply and transfers electrical loads to the generator within seconds of an outage. By doing so, it ensures safety and continuity without requiring manual intervention.

Transfer switches can be open-transition, closed-transition, or manual, depending on application needs. Critical facilities, such as hospitals, typically use closed-transition switches to avoid any power gaps, while commercial buildings may opt for simpler solutions. Selecting the right ATS is as important as the generator itself.

Reliability and Maintenance

Reliability is the primary measure of an emergency generator's effectiveness. Studies have shown that poorly maintained systems face significantly higher failure rates, often caused by fuel contamination, dead batteries, or clogged filters. Regular inspections and load testing are essential to confirm readiness.

Maintenance schedules typically include monthly or quarterly run tests, annual servicing, and periodic replacement of consumable parts. Facilities following these practices can expect generators to perform when needed, while neglect often results in costly failures during critical outages.

• Fuel System Checks – Inspect tanks for contamination, leaks, and degradation

• Battery Testing – Verify charge and replace aging batteries before failure

• Cooling System Maintenance – Monitor coolant levels, hoses, and heat exchangers

• Exhaust and Ventilation – Clear obstructions and ensure proper airflow for safe operation

• Load Bank Testing – Simulate real load to confirm generator performance under stress

• Scheduled Servicing – Replace filters, belts, and fluids at manufacturer-recommended intervals

Installation and Site Considerations

Placing an emergency standby generator involves more than just setting the equipment on a pad. Factors such as ventilation, exhaust routing, sound attenuation, and fire safety must be addressed to meet both performance and regulatory requirements. Proper installation also affects overall reliability, as poor site conditions can shorten equipment life or compromise operation during emergencies.

Environmental conditions also matter. Units in flood-prone regions may need to be elevated, while those in seismic zones require reinforced mounting. Noise regulations and local permitting often dictate the types of enclosures and their placement relative to occupied areas, making careful planning essential before commissioning a system.

• Ventilation – Ensure adequate airflow for engine cooling and combustion efficiency

• Exhaust Routing – Direct exhaust gases safely away from occupied areas

• Noise Control – Use enclosures, barriers, or mufflers to meet local noise limits

• Flood Protection – Elevate equipment in flood-prone locations to prevent damage

• Seismic Resilience – Anchor and reinforce generators in earthquake-prone regions

• Permitting & Compliance – Follow municipal codes, zoning laws, and environmental rules

If you’re planning an installation, our guide on what size emergency generator do I need offers practical advice for load calculations and system design.

Monitoring and Controls

Modern emergency generators are equipped with advanced monitoring systems, enabling facility managers to remotely track their performance. Through IoT integration, data such as runtime, load profiles, fuel consumption, and alarm conditions can be monitored in real time.

This level of visibility not only improves reliability but also reduces downtime and operating costs. Predictive diagnostics help operators schedule maintenance proactively, minimizing risks of unexpected failure during actual emergencies.

• Remote Monitoring – Real-time access to generator status from any location

• IoT Connectivity – Integration with building management and microgrid systems

• Alarm Notifications – Immediate alerts for faults, low fuel, or overheating

• Data Logging – Records load history, runtime hours, and test results

• Predictive Diagnostics – Identifies trends that could indicate pending failures

Use Cases and Examples

Hospitals rely on generators to maintain the continuous operation of surgical suites, emergency rooms, and intensive care units. Without them, patient safety would be severely compromised during even short outages.

Data centers, which process and store vast amounts of digital information, rely on backup power to guarantee uptime. A single outage can cost thousands of dollars per minute, making generators an essential safeguard against financial loss and reputational damage.

• Hospitals – Life-support equipment, emergency lighting, and surgical suites

• Data Centers – Continuous server operations and network reliability

• Industrial Facilities – Prevents downtime in manufacturing and production lines

• Commercial Buildings – Keeps elevators, HVAC, and lighting systems functional

• Residential Complexes – Provides power for essential services in multi-unit dwellings

Data centers often combine generators with UPS (Uninterruptible Power Supply) infrastructure. Explore our guide on designing data center UPS systems to learn how reliability is maximized in high-demand environments.

Challenges and Trends

Despite their importance, they face challenges. Fuel availability can become constrained during large-scale disasters, while environmental regulations push facilities to reduce emissions. Efficiency at partial loads also remains a technical concern.

To address these issues, newer systems integrate with microgrids, renewable energy, and energy storage solutions. Hybrid configurations improve sustainability while maintaining the resilience required by critical facilities. Features like black start capability further expand their role in disaster recovery.

• Fuel Supply Risks – Shortages during disasters can limit generator availability

• Emissions Regulations – Stricter limits require cleaner-burning technologies

• Partial Load Inefficiency – Generators often run inefficiently at light loads

• Hybrid Systems – Pairing generators with solar and storage for resilience

• Black Start Capability – Ability to restart without external power after a blackout

Regulatory and Standards Compliance

Emergency generator systems are governed by strict codes and standards. NFPA 110 defines performance requirements for emergency and standby power, while NEC Articles 700, 701, and 702 regulate installation practices.

In Canada, CSA C282 establishes safety and reliability standards for emergency power in buildings. Compliance not only ensures legal adherence but also improves performance, safety, and insurability of the system.

An emergency standby generator is more than an accessory—it is a vital safeguard against disruption. With proper fuel selection, installation, monitoring, and maintenance, it provides assurance of continuous power in the moments that matter most.

Facilities that prioritize resilience through reliable backup power systems can minimize risks, maintain safety, and secure operational continuity during unforeseen outages.

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Tips for Selecting UPS System: assess load capacity, runtime, topology (offline, line-interactive, online), power factor, battery chemistry, surge protection, voltage regulation, efficiency, redundancy, SNMP monitoring, and harmonics for reliable power conditioning.

What Are Tips for Selecting a UPS System?

Guidelines to choose a UPS by load, runtime, topology, efficiency, protection, and manageability.

✅ Size for total VA/W load with headroom; verify power factor.

✅ Calculate required runtime; consider battery chemistry and lifecycle.

✅ Choose topology; ensure surge protection, AVR, SNMP/Modbus monitoring.

Every day, an interruption to electrical service in homes, businesses and public sector organizations occurs, and the losses from these power outages can be extensive and of great consequence. For a business, the recovery time is significant and the costs are high. According to Price Waterhouse research, after a power outage disrupts information technology (IT) systems more than 33 per cent of companies take more than a day to recover and 10 per cent take more than a week. In addition, it can take up to 48 hours to reconfigure a network and days or weeks to re-enter lost data.

Power outages can cause substantial losses for the companies affected. According to the U.S. Department of Energy, when a power failure disrupts IT systems, 33 percent of companies lose $20,000 to $500,000, 20 percent lose $500,000 to $2 million and 15 percent lose more than $2 million. In fact, 90 per cent of companies that experience a computer disaster and don’t have a survival plan go out of business within 18 months. For risk mitigation, investing in an uninterruptible power supply can materially reduce downtime exposure.

In general, an uninterruptible power supply (UPS) protects IT equipment and other electrical loads from problems that plague our electrical supply. It prevents hardware damage typically caused by surges and spikes, prevents data loss and corruption, and provides availability for networks and other applications while preventing downtime. In some cases, a UPS provides enough battery runtime to ride through brief outages; in other cases, they provide hours of runtime to ride through extended power outages. For readers new to the topic, this overview of what a UPS system is provides helpful context for comparing options.

Here are the top tips to help you find and maintain a UPS system. 

TIP #1
Understand Existing Power Infrastructure

This is a critical first stop in the qualification and sales process of choosing a UPS. While you may focus on larger, three-phase power systems, the majority of IT managers are dealing primarily with single-phase equipment, often at the rack level. Many existing computer room and small to mid-sized data centers have single-phase loads at the rack level. Ground-up designs are increasingly moving three-phase power to the point of utilization to gain efficiencies and reduce costs, creating great opportunity for three-phase solutions in new construction. If you are planning new builds or major retrofits, this guide to designing data center UPS infrastructure highlights architecture choices and common pitfalls.

TIP #2
Consider The Installation Environment

It’s imperative to understand how a prospective UPS will be deployed. Since most environments support several different solutions, you may need to evaluate these options. For environmental constraints and form factors, this primer on UPS power supply considerations outlines common deployment trade-offs.

TIP #3
Determine The Power Load

The VA or watt rating of your power loads is one of the most important factors in identifying the right UPS. After identifying the power environment (if the UPS needs to be single- or three-phase), the size of the UPS further narrows the selection. In single-phase deployments especially, it often makes sense to select a UPS that exceeds current power requirements but offers greater runtimes and allows for future growth.

TIP #4
Determine Availability Requirements

This is where you need to determine your true runtime requirements. During an outage, you need enough battery runtime to gracefully shut down systems or switch to backup generators. While runtime may seem like a simple thing to quantify, understanding the facts behind the numbers help contribute to the development of end-to-end solutions. Generally, the amount of runtime required can significantly affect the solution cost, but many Eaton solutions are actually more cost-effective in extended runtime applications. Improving conversion efficiency also extends battery autonomy, and many insights on high-efficiency UPS systems can inform runtime planning.

TIP #5
Determine Scalability Needs

It’s always important to consider your future expansion needs when evaluating UPS solutions. For cost-conscious or budgetconstrained customers, a UPS with inherent scalability often proves to be the best value in the long run, allowing you to increase capacity without purchasing additional hardware. A simple kVA upgrade is all that’s needed to enable a UPS with inherent scalability to operate at full capacity. You may want to service the UPS yourself. If that’s the case, look for a unit that allows you to add capacity with power and/or battery modules. While modular solutions—including multiple, paralleled systems—are often a more affordable option initially, they can be a more expensive solution over the long term due to added hardware and installation costs. Depending on your needs, a larger, centralized, non-modular system with inherent scalability might ultimately be the most cost-effective solution.

TIP #6
Consider Power Distribution

It is important for you to consider how power will be delivered to your critical equipment. In some cases, you may simply plug loads directly into the UPS. In others, you may need large PDUs to distribute power. You may also incorporate rack-based power strips or ePDU units into your design.

TIP #7
Research Manageability Software

While a UPS protects the attached load during a power outage, power management software is required to ensure that all work-in-progress is saved and that sensitive electronic equipment is gracefully shut down if the power outage exceeds the battery runtime of the UPS. Without software, the UPS simply runs until its batteries are depleted and then drops the load. Most power management software is shipped with the UPS and is usually available as a free download online as well. To align shutdown policies with hardware capabilities, a concise explainer on UPS uninterruptible power supply technologies can help you map software features to device topologies.

TIP #8
Consider Monitoring Capabilities

In addition to this basic functionality of UPS software, you should consider the implementation of monitoring and manageability capabilities. These capabilities include: power event notifications, including emails, pop-up alerts and text messages to pre-designated recipients; logging of power events; advanced capabilities in virtual environments, including integration into VMware’s ESXi and vSphere and Microsoft’s Hyper-V; dedicated battery monitoring and advanced service notifications; and remote monitoring by service personnel from the UPS manufacturer.

TIP #9
Access In-House Technical Capabilities

While you may value the ability to service your own equipment, the vast majority of IT and facility management professionals prefer the peace of mind that comes with full factory support through on-site service or an advanced UPS exchange agreement. To make an informed decision on service support, you must accurately assess your own technical and service capabilities. You should also look at the various UPS product designs to gauge how easy it is to swap out battery and power modules. Before committing to self-service models, review common UPS risks so your staffing plans account for maintenance, safety and lifecycle costs.

TIP #10
Prioritize To Maximize Budgets

Although the latest performance features of a UPS may fit nicely with what you are looking for, budget constraints may force you to make trade-off decisions. Be prepared to prioritize your needs for redundancy, scalability, efficiency, software management, modularity and serviceability.

From: Power Quality, Grounding & UPS Handbook, Vol 12, The Electricity Forum

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• Electrical Generators and UPS Channel

UPS ratings define uninterruptible power supply capacity, kVA/kW, power factor, efficiency, and battery runtime, guiding load sizing, surge protection, and runtime planning for data centers, industrial controls, servers, and critical infrastructure.

What Are UPS Ratings?

UPS ratings define UPS capacity—kVA/kW, power factor, efficiency—and runtime to align loads with required reliability.

✅ Measure kVA, kW, and power factor to size loads accurately.

✅ Check efficiency curves and THD for cleaner, cooler operation.

✅ Verify battery runtime at specified load, temperature, and aging.

The uninterruptible power supply (UPS) industry is very competitive. Products are often selected based on the cost per volt-ampere (VA) of output power. In such markets, assessing designs such as high-efficiency UPS systems can clarify total cost of ownership beyond headline VA pricing.

This approach works well when vendors have tested their UPS system with common computers so that the user can select from a table that shows model and backup time. This approach does not work well when choosing a UPS system for demanding applications that involve cyclical loads such as starting electric induction motors. These motors are often used in air conditioners, conveyor belts and for gate control. For these scenarios, following tips for selecting a UPS system helps ensure adequate surge handling and motor-start margin.

Applications that require extended backup time also places additional demands on a UPS system. It is a little bit like automobile brakes. The average driver is happy as long as the car stops. Brakes basically convert kinetic energy to heat. The average car buyer does not care about rotor and caliper size and has never experienced brake fade. If the car is taken to the track and driven hard, it won’t take long before the brakes fail from overheating. Few cars are designed with brakes that can take such abuse. It really doesn’t matter to most people, so most cars have small brakes that are not up to rigorous performance standards. UPS cases are opposite because these systems are called upon to start motors, but comparable, due to high currents and the heat that is generated. When runtime is extended and currents rise, understanding UPS risks helps avoid thermal stress and premature failure.

Power Factor (also known as displacement power factor) is the cosine of the phase angle φ between the current and voltage sinusoidal waveforms. The power in a circuit that is transformed from electric to non-electric energy is called real power. The portion of power that is the result of stored energy, and which returns to the source over a full line cycle, is known as reactive power. Apparent Power Factor (also known as distortion power factor) is real power in watts (W) divided by the product of Vrms x Irms and is typical of the current drawn by a switchmode power supply that is not power factor corrected. The typical apparent power factor for such a power supply is 0.6 to 0.7. Apparent power factor is neither leading nor lagging, as there is no phase angle to speak of. If these terms are unfamiliar, reviewing what is a UPS system can help connect power factor concepts to real equipment behavior.

The UPS industry rates most products in VA which does not include the effects of harmonic current). A hypothetical UPS model might be called XX-1000 leading the prospective customer to assume that the UPS system could provide 1kVA of apparent power to a critical load. Studying the specifications reveals that the unit is capable of providing only 0.7kW of real power. The typical specification does not state power factor or maximum continuous current, nor does it allow for harmonic distortion. Not knowing load power factor or maximum current the user will not know for sure if the unit can operate at 1kVA. We will here argue for a more sensible industry specification for the discerning customer. Accordingly, a careful read of any UPS power supply specification should verify kW rating, maximum continuous current, and distortion limits to avoid misapplication.

Consider a user with an application that requires 1kVA of apparent power at an apparent power factor of 0.7 which is typical for computer loads. In such cases, confirming that the chosen UPS uninterruptible power supply can deliver the required kW at the actual load power factor will prevent nuisance trips.

Since the UPS system is only rated for 0.7kW, it would overheat fairly quickly as its inverter and inverter transformer are not rated to handle more than 0.7kW. This would not be a problem if the UPS system is designed with internal batteries to provide backup power for 10 to 20 minutes. It becomes a major problem if the customer connects and external battery bank to increase the backup time to several hours. This is often the case with special applications such as security and wireless systems. Why does the UPS industry use the obviously misleading VA specification (sometimes called computer VA). This practice originated in the 80s, as a now defunct company attempted to gain competitive advantage. It didn’t take long for the rest of the industry to follow. For extended-backup deployments, selecting an uninterruptible power supply with an honest watt rating and ample thermal headroom is essential for reliability.

HEATER

10kVA heater is a resistive load with a power factor of 1. Real power is 1kVA x 1 = 1kW and no reactive current is returned to the inverter, so the UPS system is unable to supply the load as it exceeds its rating by 0.3kW

ELECTRIC MOTOR

1kVA electric motor is a resistive/inductive load with a power factor of 0.8. Real power is 1kVA x 0.8 = 0.8kW with 0.6kVAR reactive power returned to the inverter, so the UPS system is unable to carry the load.

COMPUTER

1kVA computer is a rectifier/capacitor, non-linear load with a power factor of 0.7. Real power is 1kVA x 0.7 = 0.7kW with a 7.14kVAR of harmonic distortion current returned to the inverter. The above three cases clearly demonstrate the inadequacy of the VA-rating system. It is obvious that all of the above three cases would require a 1kW UPS system. This leads to the inescapable conclusion that it would be much better to rate UPS products in watts (W) instead of volt-ampere (VA).

From: Power Quality, Grounding & UPS Handbook, Vol 12, The Electricity Forum

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Emergency power supply systems provide backup electricity during outages to maintain critical operations. Common in hospitals, data centers, and industrial facilities, they ensure electrical reliability and safety in emergencies.

What is an Emergency Power Supply?

An emergency power supply is a system designed to deliver electricity when the main power source fails.

✅ Provides backup electricity during outages to maintain safety and operations

✅ Supports essential systems like alarms, elevators, and life-support equipment

✅ Uses generators, batteries, or UPS systems to ensure uninterrupted power

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An emergency power supply (EPS) is essential for maintaining electricity when an outage or natural disaster disrupts the grid. It's essential to have a backup supply to ensure that your home or business has electricity when it's needed the most. Several emergency supplies are available, including generators, uninterruptible power supply (UPS), battery backup, and portable supplies. Proper voltage compliance is critical when integrating emergency power systems into sensitive electrical infrastructure.

During power outages, having access to backup power is essential for maintaining safety and comfort. Battery packs and portable power stations offer convenient solutions by supplying temporary electricity to essential devices and appliances. These systems are especially useful in areas prone to frequent outages, providing reliable, portable, and rechargeable backup power when the grid fails.

Backup electricity is essential to ensure you have an emergency supply. Generators are a popular backup option due to their reliability and output. A gas-powered generator can provide electricity to larger appliances and tools that require more energy, but it can emit fumes and require regular maintenance. A UPS can deliver electricity for a short period, typically a few minutes to a few hours, depending on the battery size and usage. A battery backup system is another option that keeps small appliances and tools running during an outage.

Portable supplies are a versatile and eco-friendly option for emergency power supply. A portable generating station is a large battery that can be charged using solar power panels, a wall outlet, or a car charger. They are typically small and lightweight, making them easy to transport and store. Portable stations come equipped with USB ports, AC outlets, and other connectors, allowing them to feed small appliances, electronic devices, and tools. In addition, these devices are eco-friendly when charged using solar panels or other renewable energy sources. If you're planning large-scale installations, review best practices for designing data center UPS infrastructure to ensure reliability and scalability.

Emergency Power Supply Comparison Table

Preparedness is crucial in the event of outages. First, planning and understanding your emergency power supply needs during an emergency is essential. Having a plan in place for how you will use your EPS during an outage is also necessary. Finally, I'd like to emphasize that periodically testing your EPS to ensure it functions correctly and the battery is fully charged is crucial. 

Standby electricity is another backup option to consider. Standby systems are typically permanent fixtures installed in a home or business and automatically activate during an outage. Standby systems can keep your entire home or business running for an extended period, making them a reliable emergency power supply source.

Emergency lighting is another aspect of an emergency power supply. Adequate emergency lighting during an outage is crucial for safety reasons. A UPS, battery backup system, or generator can supply emergency lighting.

Having an emergency power supply is crucial for anyone who wants to be prepared for emergencies. There is an EPS solution for every need and budget, from generators and UPS systems to portable stations and solar panels. Planning and understanding your EPS needs during an emergency is crucial to ensure that your EPS will keep your home or business running smoothly when the grid goes down. With proper emergency power sources, you can rest assured that you will always have electricity when you need it most. When considering a source of energy, learning how a generator works helps you make informed decisions for emergency use.

Frequently Asked Questions

What is an emergency power supply, and how does it work?

An emergency power supply is a backup source that can provide electricity during an outage or emergency. It converts stored energy into usable electricity when the primary energy source fails. Emergency power supplies can take various forms, ranging from gas generators to battery backup systems, and can energize different devices and appliances depending on their capacity. To optimize long-term performance, compare UPS devices using real-world UPS ratings and manufacturer specifications.

How Long Does an EPS Last?

The length or period of time that an EPS can last varies depending on the type of energy source, the amount of energy being used, and the capacity of the supply. Gas generators, for example, can provide energy for several hours or days, depending on the amount of fuel available. 

What Are the Different Types?

There are several types of systems available, including:

• Generators - Gas generators are a popular backup option due to their reliability and output.

• Uninterruptible Power Supply (UPS) - A UPS is a battery backup system that provides electricity for a short period, typically ranging from a few minutes to a few hours, depending on the battery size and usage.

• Battery Backup - A battery backup system is another source of electricity that can keep small appliances and tools running during an outage.

• Portable Supplies - Portable, large stationary lithium-ion batteries that can be charged using solar panels, a wall outlet, or a car charger.

Facilities with DC equipment may benefit from integrating a DC generator into their backup systems.

How Do I Choose the Right System for My Needs?

Choosing the right emergency supply depends on several factors, including the devices you want to use the time you need electricity, and your budget. Gas generators are a good option for larger appliances and tools that require more electricity, but they can be expensive to operate and emit fumes. Battery backup systems and portable units are better for smaller devices and have the added advantage of being eco-friendly. A UPS is an excellent option for serving critical systems such as computers and servers during an outage.

What Maintenance and Testing is Required?

Maintaining and testing your emergency power supply is crucial to ensure it works correctly when needed. Gas generators require regular maintenance, including oil changes and filter replacements, to ensure optimal performance. Additionally, battery backup systems and portable stations should be charged periodically to ensure the battery is fully charged and functioning properly. It's also important to regularly test your EPS to ensure it functions properly and provides the necessary electricity during an outage.

Are There Any Safety Concerns?

Yes, there are safety concerns when using an emergency power supply. Gas generators emit fumes that can be harmful if not used in a well-ventilated area. They should also be kept away from flammable materials and never used indoors. Battery backup systems and portable stations should be handled with care to prevent overheating or damage to the battery. Always read the manufacturer's instructions and follow safety guidelines when using an EPS.

How Can I Integrate One into my Business's Emergency Preparedness Plan?

Integrating an emergency power supply into your business's emergency preparedness plan is crucial to ensure that your business can continue to operate during an outage. First, consider the critical systems and devices' needs, and ensure that your EPS can provide enough electricity to keep them running. Next, how you will use your emergency supply during an outage and test it regularly to ensure it works correctly. Finally, train your employees on the proper use of the emergency supply and any safety concerns associated with it.

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