Advantages and Features of EPS Emergency Power Supplies

EPS emergency power supplies can be regarded as an emerging industry that has experienced rapid growth only in the past two years. Compared with the well-established UPS technology, EPS systems share some similarities but also exhibit key differences. Specifically, both technologies are designed to maintain AC power supply to the load during utility power failures or outages, and both employ IGBT inverter technology and pulse-width modulation (PWM) techniques.

The EPS emergency power supply is a high-tech, environmentally friendly product that leverages inverter technology, CPU control, digital circuitry, and highly integrated electronic components. It primarily consists of an inverter, auxiliary power supply, rectifier–charger, battery pack, and controller, providing a secondary or tertiary power source for Class I and Class II loads, critical electrical equipment, fire-fighting systems, and emergency lighting. The EPS fire-fighting emergency power supply features simple maintenance, can operate unattended, supports fire-fighting interlock and automatic operation, and enables remote or building-integrated intelligent monitoring. Its start-up time is only 0.1 seconds—significantly shorter than that of diesel generator sets—while the total investment is comparable to that of diesel generators.

However, for motor-type loads with relatively low output power, the Shanghai Yaoliang EPS fire emergency power supply—specifically designed and developed for fire-fighting emergency applications—currently boasts a certain degree of advanced technology and practicality. It enables microcomputer-based monitoring and control, allowing automatic operation of fire-fighting emergency lighting, rolling shutters, fire-service elevators, water pumps, smoke-extraction fans, and other fire-fighting equipment. Such products are commonly deployed in high-rise buildings, airports, telecommunications network server rooms, hospitals, and major venues. The EPS fire emergency power supply offers the following advantages:

1. When mains power is available, the system remains in a static, noise-free state; when mains power is unavailable, its noise level is less than 60 dB. No smoke exhaust or vibration isolation measures are required, and the system inherently poses no fire hazard.

2. Automatic switching enables unattended operation and energy savings; the switchover time between grid power and EPS power is 0.25 seconds, and in special circumstances, zero-switching can be achieved.

3. It can directly drive motor-type loads without the need for a soft-start device.

4. Reliable operation: In critical applications, a dual-unit hot-standby configuration can be employed to ensure dependable power supply during accidents and fires; the main unit has a service life of over 20 years, while the battery lasts for 5 to 10 years or more.

5. Designed to withstand harsh environments, it can be installed in basements, switchgear rooms, or even building shafts, and may be located directly adjacent to the emergency load service area to minimize power distribution lines.

6. Strong load-carrying capability: EPS fire emergency power supplies are suitable for equipment with inductive, capacitive, and mixed loads, such as fire-service elevators, water pumps, fans, and emergency lighting.

7. For certain high-power electrical equipment, such as fire pumps and fans, the EPS fire emergency power supply can be directly connected to the motor for variable-frequency start-up, after which the system transitions to normal operation.

8. Emergency backup time: the standard model provides 60 minutes (with a delay interface). As evident from the seven points above, Shanghai Yaoliang EPS fire emergency power supplies are widely used in various applications, and their critical role is self-evident.

Applications and Characteristics of EPS Emergency Power Supplies in the Fire Protection Field

(1) When the power grid is energized, the system operates in a static state with no noise—sound levels are below 60 dB—and requires no smoke extraction or vibration isolation. Additionally, it is environmentally friendly and poses no fire hazard.

(2) Automatic switching enables unattended operation and energy savings, with a switchover time of 0.1 to 0.25 seconds between grid power and EPS power supply.

(3) Strong load-carrying capability: EPS is suitable for equipment with inductive, capacitive, and mixed loads, such as fire-service elevators, water pumps, fans, and emergency lighting. In particular, during emergency or fire-induced power-cut scenarios, the power supply can operate at a 120% overload condition until the battery is fully depleted.

(4) Reliable operation: In critical applications, a dual-unit hot-standby configuration can be employed to ensure dependable power supply during accidents and fires; moreover, the main unit has a service life of over 20 years, while the batteries last for more than 5 years.

(5) Designed to withstand harsh environments, it can be installed in basements, switchgear rooms, or even building shafts, and may be located directly adjacent to the emergency load service area to minimize power distribution lines. It can be locally controlled or integrated with fire-fighting interlock control.

(6) For certain high-power electrical loads, such as fire pumps and fans, the EPS can be directly connected to the motor for variable-frequency start-up, after which the system transitions into normal operation, thereby eliminating the need for soft-start devices and control panels for the motor.

What are the advantages of EPS compared with generator sets?

(1) During a power outage, the EPS inverter can automatically start up very quickly—typically in less than 3 seconds (and, for special applications, as little as 0.1 seconds)—whereas an standby generator requires 5 to 30 seconds to start automatically; systems without an automatic start function take even longer.

(2) EPS systems produce no exhaust or flue gas, generate no noise or vibration, and are environmentally benign, whereas diesel generators emit sulfur dioxide, produce substantial exhaust and smoke, generate significant noise and vibration, and resemble a large bomb in terms of their operational characteristics, making them highly unsafe. They require stringent fire-prevention measures at all times. In high-rise buildings, diesel generator sets are typically installed in basements, which poses considerable design challenges and results in higher construction costs. Comprehensive consideration must be given to ventilation, cooling, flue-gas exhaust, vibration isolation, and noise reduction systems.

(3) EPS systems are easy to maintain, can operate unattended and automatically, and can be monitored via computer, whereas generators require dedicated personnel for supervision and regular maintenance.

(4) EPS inverter power supply offers stable voltage and frequency, excellent waveform quality, zero interference, and high efficiency; in contrast, generator-powered systems suffer from unstable voltage and frequency as well as low efficiency.

(5) EPS systems boast strong overload capacity and comprehensive protection features, with a low power-matching ratio to the load—typically 1:1—thereby reducing capital investment. In contrast, generator sets have limited overload capacity and basic protection functions, requiring a higher power-matching ratio with the load—usually 1.5—which increases capital expenditure.

(6) EPS requires a one-time capital investment with virtually no ongoing operating costs, whereas generator auxiliary equipment is expensive to procure and incurs substantial ongoing operating expenses.

With societal progress and development, environmental requirements are continually rising, and fire safety awareness is receiving increasing attention. EPS, owing to its unique advantages, is being recognized and adopted more widely; in a given project, it can be flexibly deployed at the end of fire-supply circuits, in individual critical applications, and in a variety of other scenarios. When selecting emergency power sources, the choice is no longer limited to diesel generators alone, as each type of system has distinct characteristics that make it suitable for different projects, thereby providing stronger safeguards for overall public safety.