Under the deal, Eaton will provide over 130 bays of its MMS-series dual-busbar MV vacuum switchgear.
The equipment is slated to be delivered and installed by the end of 2014.
Eaton electrical systems and solutions division manager David McCabe said the new equipment is being installed at two major 132/11 kV distribution substations in central London, one at St Pancras Station, the other in the Whitechapel area.
"In both cases, the existing substations are being upgraded to cope with growth in demand which will subsequently help to reinforce the London network and its resilience," McCabe said.
Eaton will install 62 bays of MMS vacuum switchgear in a new switch house at St Pancras and supply six bays of MMS switchgear, which will be installed on temporary basis at the adjacent Brill Place substation to meet power requirement for a major energy user on the site.
Once the main project is complete, these six bays of switchgear will be relocated to the main St Pancras substation, where they will provide spare capacity to cope with future growth in demand.
At Whitechapel, Eaton will supply 69 bays of MMS switchgear configured as three separate boards, each fed by a different 132/11 kV transformer.
The boards, which are on two floors of the building, will be linked with Eaton insulated busbar connectors.
UK Power Networks’ project manager at St Pancras Lucio Polito said, "The compact construction of Eaton’s MMS switchgear makes it an ideal choice for this project, as the space available in the new switch house is restricted by the constraints of the site."