Constant Power Services Ltd (CPS Ltd)

Constant Power Services Ltd (CPS Ltd)


Constant Power Services Ltd (CPS Ltd)

Constant Power Services Ltd was originally formed in the late 1980’s to provide a reliable source of service support and engineering in the field of Uninterruptible Power Supplies (UPS) and Power Conditioning. The company is now well established and forms an integral part of the Italian Riello Elettronica Group.

Constant Power Services occupies a 25,000 sq/ft premises in Letchworth, Herts which accommodates both Sales and Service activities as well as a large warehouse facility. Stock UPS units are available up to 400kVA as well as a comprehensive spares holding located at our Letchworth head office as well as service hubs in Huddersfield, Southampton and Edinburgh.

Directly employed Sales and Service engineers are based at the Letchworth office and throughout the UK enabling quick and efficient response to both sales enquires and service related callouts.

Your Total Power Solution


Your Total Power Solution

We have worked extensively towards providing a ‘total power solution’ having installed numerous Generator and UPS packages complete with associated switchboards for distribution and auto changeover facilities. Working with specialised partners, Constant Power Services has consolidated it’s position as a major UPS supplier to Hospital and Health Authorities throughout the UK.

  • Uninterruptible Power Supplies
  • Central Battery Systems
  • Low Voltage Switchgear
  • Static Transfer Switches
  • Diesel Generators
  • Containerised Power Solutions
  • DC Flywheels
  • UPS Maintenance with 24-7 Call-out Facility
  • “CPS Watch” Remote Monitoring and Diagnostics Facility
  • Battery Replacements and Upgrades
  • Factory Witness Testing of UPS and Generators in Italy

Sales Support


Sales Support

Constant Power Services Ltd aims to provide excellent pre-sales support to ensure that the correct system is selected to suit your specific application and budget. We have a dedicated internal sales team based at our Hitchin head office, responding to your enquiries with efficient and fast quotation turnaround, product advice, technical documentation and CAD drawings. An external sales team is also available covering the whole of the UK to discuss your projects and our products in person.

The Projects Team


The Projects Team

Constant Power Services has always maintained a high level of returning customers. Our approach has always been to give attention and resource to all our projects irrespective of their size. The CPS Projects Team are available to ensure that all aspects are considered including site access, equipment location, specialist positioning as well as environmental limitations; which are all carefully planned to suit financial budgets and project programs. Site surveys, customer handovers, client demonstrations and basic training are also available to ensure complete customer satisfaction.

UPS Maintenance, Spares Support and CPS Watch Remote Monitoring and Diagnostics


UPS Maintenance, Spares Support and CPS Watch Remote Monitoring and Diagnostics

Constant Power Services offers a variety of maintenance agreements which can be fully customised. We have a team of engineers covering the UK providing round the clock support all inclusive of parts and labour, both during and after the warranty period.  Our engineers are fully trained on our entire UPS range and carry an extensive kit of spare parts to all site visits, ensuring a high repair rate and avoiding return visits. GSM technology now enables us to offer our “CPS Watch” facility enabling interrogation of your UPS before site attendance.

Premium Tower UPS - 700 to 3000 VA


Premium Tower UPS - 700 to 3000 VA

The PREMIUM TOWER series uses on-line double conversion technology providing the highest level of reliability and protection for critical servers, network devices and voice/data applications. The PREMIUM range is fully microprocessor controlled providing high efficiency levels and greater configuration options.

Additional matching battery modules are available for extended runtimes.

Premium Rack UPS - 1000 to 3000 VA


Premium Rack UPS - 1000 to 3000 VA

The PREMIUM RACK series uses on-line double conversion technology providing the highest level of reliability and protection for critical servers, network devices and voice/data applications. The PREMIUM range is fully microprocessor controlled providing high efficiency levels and greater configuration options.

The entire range is based on a 2U design with additional 2U battery boxes available for extended runtimes.

Starlet M - 10 to 120 kVA


Starlet M - 10 to 120 kVA

The Starlet M UPS achieves the highest possible level of on-line double-conversion performance (VFI-SS-111) as defined within IEC EN 62040-3 and is designed to sit discreetly alongside traditional comms room equipment.

Zero impact source

The range is the ideal solution for installations where the power supply is limited, where the UPS is supported by a generator or where there are compatibility problems with loads that generate harmonic currents.

  • Low Input current distortion < 3%
  • High Input power factor 0.99
  • Power walk-in and start-up delay functions

Sirius P UPS - 100 to 600 kVA


Sirius P UPS - 100 to 600 kVA

The Sirius P UPS uses a Power Factor Corrected IGBT Rectifier with Digital Signal Processors (DSP) to achieve the highest level of on-line double-conversion performance (VFI-SS-11) as defined within IEC EN 62040-3.

The range has a compact footprint (only 0.85m2 for a 250kVA UPS) with an enclosure design that enables maintenance access from the front and “back to wall” installation; combine this a with an integral output transformer providing Galvanic Isolation through the inverter, make this the versatile choice for modern data centres and industrial loads.

Zero impact source

The range is the ideal solution for installations where the power supply is limited, where the UPS is supported by a generator or where there are compatibility problems with loads that generate harmonic currents.

  • Low Input current distortion < 3%
  • High Input power factor 0.99
  • Power walk-in and start-up delay functions
  • Optional Generator card enabling inhibit of battery recharge
  • Optional UGS and PSJ systems for Synchronisation and Dual Bus systems

MultiGuard Modular UPS - 15 to 120 kVA


MultiGuard Modular UPS - 15 to 120 kVA

The MultiGuard is a scalable three phase UPS providing online double conversion technology that is designed to sit discreetly alongside traditional comms room equipment.

The ‘modular’ solution provides scalability for continued resilience or future capacity when loads increase without the need to find more valuable floor space within your comms room. Based around a 15kVA module which can be supplied in either 30kVA, 60kVA or 120kVA cabinet solutions providing the flexibility to suit both small and large applications

Diesel Generator Sets


Diesel Generator Sets

Our Partnership with ELCOS Generators in Italy enables competitive proposals with market leading availability.

  • Ratings from 37kVA to 3.3mVA
  • Standby and prime rated applications
  • Bespoke soundproofing for reduced noise
  • Extended integral and external fuel tanks
  • Volvo, Cummins, Perkins, Iveco & Mitsubishi Engines
  • Manufactured in Italy to ISO9001:2008
  • Large stock - reduced leadtimes

Containerised Power Solutions


Containerised Power Solutions

The Containerised Power Solutions from Constant Power Services Ltd combine the high performance Sirius P UPS, the award winning Vycon DC Flywheel and an ELCOS Diesel Generator to provide a reliable, uninterrupted and sustained Emergency power supply. The solution uses either a 20’ or 40’ container which can be considered for both temporary and permanent applications.  A purchase investment can provide an effective emergency solution; deployed to various sites as and when required.

Support resources

Call Applegate +44 (0)345 600 7177 AS