Power You Can Trust



Over a number of years, we have worked very closely with this global Data Centres operator to support in the design, supply installation and commissioning of a range of high quality and cost-effective generator packages of various ratings and configurations. To date we have designed, supplied, installed and commissioned nearly 120 generating sets of various ratings and configurations. All packages being designed to meet the power requirements of a particular data hall, the space envelope available for the generator package, scalability of the requirement as well as electrical distribution and level of operation redundancy required, all delivered to a very tight client driven programme. To fully explore the innovative packages that WB Power Services have been able to offer this client, the power range, flexibility offered by Kohler generating sets, control system flexibility and acoustic packaging option and options: this is the second of three different case studies we have prepared based on the work completed at this site and for this client. The early design brief issued by the client sought for:

  • Scalability of standby power capacity to cater for a range of data hall footprints / capacities
  • Utilisation of the same generator building blocks for ease of maintainability and user familiarity
  • Control system adaptability with high levels of site wide connectivity
  • Good product adaptability but with short production times for shortest possible site build times
  • Offer a more compact solution

To cater for the ever-increasing size of data halls and growing power densities it was necessary to select a much larger generator rating whilst maintain a competitive / kW price, short lead times all of which was accompanied by a move to power distribution at 11kV. With power densities continuing to increase the client wished to reduce the overall footprint of each data hall generator package. Working with the client and the design team a gantry stacking solution was developed.


Working closely with the client we identified that a 1650kVA 1320kW DCC rated generating set offered the optimum capacity and flexibility to meet their current and foreseeable needs. WB matched this requirement to our partner Kohler’s KD1650. When married to an appropriately rated alternator the Kohler compact and highly reliable 20 cylinder 45 litre KD45V20-5DES engine can deliver full DCC power at its standby rating.

The generating sets were housed in a custom made acoustic containers rated to achieve a noise level of 65dBA @ 1m complete with a standard day tank and all internal lighting and ventilation. The attenuation package was designed to accommodate a horizontal discharge arrangement connected to a 90 degree upward bend / plenum, then onward to a 12m high discharge duct. The roof mounted exhaust gas silencers were housed in an insulated box arrangement before being directed into the ducted discharge air flow. The final discharge height configuration was determined following extensive modelling undertaken by WB which also considered potential future expansion of the site.

The key adaptations on these sets were:

  • The addition of a dual output circuit breaker package which was designed to facilitate local LV load bank testing of each individual set without the need for an attendant HV AP.
  • The provision of a dual starting battery, dual battery charge and dual starter motor package. The generating sets were deployed in groups of five (N+1)


All of the generating sets utilise the sophisticated Kohler AMP802 control panel and are configured for setto-set synchronising. The AMP802 is the control system of choice for many of our clients across multiple industries, as it offers a very fast multi set to set “deadbus synchronising” facility. When configured for this client we were able synchronise all five sets of one data hall package from start signal to accept load with within ten seconds. By utilising this method of synchronising the design effectively permitted the “soft starting of the transformers (avoiding any transformer magnetisation issues) and the load.

A key function of value to the client was the ability of the APM802 to “load match” which enables generators to drop out when not required (whilst retain N+1 redundancy) and start again when called upon. This optimises fuel consumption and reduces operating costs; those costs associated with maintenance and maintenance frequency, along with reducing emissions.

The Kohler AMP802 control system also offers a comprehensive range of remote monitoring / status interface options which include RS485 and Modbus etc which are available via ethernet, fibre optics and with key indications also as volt free connections. In this application the generating sets are connected to both the onsite BMS and EMS systems. By way of an example of the level of flexibility offered by the APM802 the fuel level of each generator day tank can be remotely identified, auto minimum fill level adjusted, or an auto tank replenishment initiated from the central control location.

With the client using an A and B output distribution system in order to both fulfil its operational requirements and facilitate on load transfer of loads from bar A to B and visa versa it was essential to provide a comprehensive breaker status monitoring system both on the 11kV ring and outward distribution network. Fitted with the prerequisite levels of I/O and using The APM802’s in built programmable logic capabilities this requirement was readily managed whilst at the same time offered for remote display to both the clients independent BMS and EMS systems.

With the APM802 system operating both the switchgear associated with achieving generator synchronisation (and Neutral Earthing Transformers) at LV and MV this means that the 11kV ring can be opened at any point without impacting system operation. The allows for all sets to feed side A or side B of both in any combination of sets. This offers total system operation flexibility.


With the development of the “stacked” solution to reduce the overall footprint of each package it was decided to move away from the conventional bulk tank and fuel distribution system. A “ structural belly tank” solution was developed that would sit under each generating set. The 20,000l bunded tanks were sized to the cleints operational requirements came complete with a fuel fill point and fuel polishing system housed in an end mounted cabinet. All elements being designed for ease of operation and maintenance.


Provided with an area of land to work with, WB set to work designing a gantry system that would be capable of accepting all of the equipment called for by the client, fully meet the operational constraints of the site and be flexible enough to accommodate a range of different power package requirements. The gantry system included all cable tray, lighting, walkways and access stairs etc all of which met the requirements of the local planning team and fire officer. The design was peer reviewed to ensure it met in full the client’s plant replacement strategy. WB took both full design responsibility as well as the extended scope of supplying and installing all interconnecting cables between the upper and lower decks..


Although five set packages were supplied during the early phases, increased power density of the installed IT equipment has seen this increase to six generating sets. The initial set size selection accompanied by the flexibility of the switchgear, gantry and control system solutions.

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