A large 1250 generator and a 400kVA uninterruptible power supply (UPS) system was installed as part of the extensive refurbishment of an old retail headquarters in Southampton for its new occupiers, a large insurance company.

Project overview

The existing building was redeveloped and, due to the nature of the business, a standby generator for the building’s datacentre and overall infrastructure was required. In addition a UPS was specified to support the data centre only. The engine size, decibel levels, power capacity and fuel capacity of the generator had all been specified. shentongroup were commissioned by the electrical contractor for the design, approval, transport and delivery and installation of the generator to meet the specification.

Design and project management

Although working within an existing building, the scope of works made the project more similar to a new build. Despite this, the job still had a number of complex design considerations.

The standby generator had to be designed to perform to specification, without the requirement for bulk fuel tanks. shentongroup designed a bespoke fuel container to meet the requirements..

The engine size had been calculated to deliver adequate power to the building allowing for ‘normal’ levels of power demand. The decibel level was specified to meet 85db at 1m, on the final test the installed reading achieved 76.7 db.


shentongroup worked together with the electrical contractor to manage the install. The most complex area to manage was the transportation and delivery of the system. The 18 tonne generator required specialist transportation due to its sheer size. Measuring 9.5 metres long, 3.5 metres wide and 3 metres wide, the system was delivered in 3 parts (main container, exhaust system and outlet attenuator) and craned in using a contract lift.


The installation of the standby generator and UPS was completed within the programmed time and covered by the shentongroup Power Care Premier package. The new occupants of Portswood House can be confident that, whether a brown-out or black-out, their business is protected.

To find out more about design and installation of standby power systems contact us 0844 888 4445 or visit www.shentongroup.co.uk/technical