Differences between UPS and CPSS

Many people still confuse UPS and CPSS and do not have a clear idea of ​​what their characteristics and functions are. Both are used to make up for a lack of electricity but are applied in different contexts. In this article we want to clarify and outline the differences between a UPS and a CPSS.

What is a CPSS?

A Central Power Supply System (CPSS) differs from a common UPS because it has precise characteristics.
A CPSS is used to power emergency systems, mainly for security lighting in public and private buildings, but also for automatic firefighting systems, fume extraction equipment, alarms and carbon monoxide detection systems.

In Europe there is a standard that lists all the characteristics that a CPSS must have in order to be used. This standard is EN 50171 “Centralized power supply systems” and, in addition to establishing the necessary requirements, it also sets out the possible configurations that can be applied to the CPSS.
Up to twenty years ago there was no law regulating emergency systems which, until then, used a distributed installation scheme where self-powered lamps were installed and then, in an emergency, they lit up without any source of energy. external.
With the approval of the EN 50171 standard, the use of CPSS was formalized for all emergency systems. Unlike in the past, they are centralized power supply systems that group all the lamps powered by the same energy source.
Using this second system brings numerous benefits including:

  • Reduction of investment and maintenance costs;
  • Simplification of the system and periodic test operations;
  • No limitation to the output power;
  • Long-term reliability.

CPSS and the EN 50171 standard

The EN 50171 standard applies to systems permanently connected to alternating current supply voltages not exceeding 1000 V and which use batteries as an alternative energy source.
Furthermore, the structure of the CPSS electric rescuer must comply with the CEI EN 62040 standard.

According to this standard, the CPSS must possess the following requirements:

  • The batteries used in the CPSS electric rescuers must have an expected life of at least 10-12 years;
  • The inverters used in the CPSS must be able to handle a constant overload of 120%;
  • The chargers used must recharge the batteries within 12 hours, starting from a low battery condition;
  • The casing of the CPSS must have excellent mechanical strength, capable of resisting heat and fire.
CPSS | EN 50171
CPSS Series 3 | EN 50171

Differences between UPS and CPSS

Central Power Supply Systems (CPSS) and Uninterruptible Power Supply Systems (UPS) have many similarities. As already explained, both products provide electricity in the event of a blackout or grid failure.

It is essential to know that these two systems are used in different contexts and for this reason they are not interchangeable.

Although CPSS and UPS have the same components, the former are designed according to regulatory standards that guarantee maximum product safety to be applied to safety systems and must comply with all the requirements of the EN 50171 standard.

In fact, the CPSS are used in the event of a power failure during an emergency and dangerous situation, such as a fire or an earthquake. Especially on these occasions, it is essential to have a lighting system that allows people to immediately identify the escape routes, especially in public places subject to crowding and in the workplace.

CPSS Models of AEC

AEC International, a leader for more than 50 years in the UPS sector, has recently launched its series of CPSS compliant with the EN 50171 standard.

The series consists of 2 CPSS which differ from each other for the number of phases, for the configurable powers and the functions that distinguish them. The 2 AEC CPSS models are:

  • CPSS 3, with configurable power from 1 up to 10KVA;
  • CPSS 7, with configurable power from 10 up to 200KVA;

There are several factors to consider before choosing the CPSS model. The infrastructure in which it will be located, the budget available and the possibility of future extension.
Thanks to the wide network of expert technicians around the world, AEC offers all its customers, in addition to the supply, also the installation and maintenance services of the CPSS available 24 hours a day, 7 days a week.

Discover the AEC CPSS series for emergency systems and contact us at info@aecups.com for more information or a quote.

AEC UPS | Power Supply

Founded way back in 1968, the AEC Group, Allis Electric Co. Ltd, is a public company listed on the Taipei Stock Exchange since 1994.

The AEC group has specialized for more than 50 years in the production of UPS for the protection of the power supply of industrial plants.


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