The work involved carrying out a survey at the substation location to ascertain if the site is suitable for automation. The survey considered the existing 11kV switchgear installed on site; network design required by NPg and signal strength tests for connectivity onto the secure communication network. The survey identifies the automation equipment to be installed and if any civils work is required.

Civil works were completed on this site, which allowed cable connections to be installed to the existing switchgear and new RTU telecontrol equipment. The new RTU was installed on a frame with umbilical cables, connecting the new actuators, which are fitted to the 11kV switches. The design incorporates fault path indicators, which are automated and wired into the RTU. These indicate back to control if a fault occurs. A power supply for the RTU is connected to the Low Voltage feeder pillar within the substation compound, which is monitored by the RTU and control centre.

Commissioning of the site is carried out by the IUS Senior Authorised Person (SAP). Final connections were made on site, with all local operational tests carried out. Once satisfied that the installation was operationally ready the SAP contacted the control desk engineer and carried out any network reconfigurations required under a system outage, to allow remote operation. Remote testing was accomplished by the control desk engineer and the automation equipment was transferred into operational use on the NPg network.

The work involves carrying out a detailed survey of a substation to ascertain if the site is suitable for automation. The survey considers the switchgear installed, network design required by NPg and signal strength tests for connectivity to a secure communication network. The survey would identify the automation equipment to be installed by approved remote terminal unit (RTU) installers, and later actuators to be commissioned by an IUS senior authorised person (SAP).

Site installation of the RTU was carried out following a successful site survey to identify where the unit would be wall-mounted and umbilical cables run between RTU and the switchgear already pre-installed. The design incorporates fault path indicators to be automated and wired into the RTU that indicate back to control if a fault occurs.

Commissioning of the site was carried out by an authorised SAP. Final connections were made onsite and local operational tests were carried out. Once satisfied that the installation was operationally ready the SAP would contact the control desk engineer and carry out any network reconfigurations required under a system outage to allow remote operation. Remote testing is accomplished by the control desk engineer and the Automation equipment made operational on the NPg network.

IUS conducted detailed surveys of these secondary 11kV substations on NPg’s behalf to ascertain the requirements for the delivery of the works. The survey encompasses asbestos removal, street work notices, if generation is applicable, network transfer at low voltage, any civil adaptions, as well as liaison with the local community via letter drops for planned outages. This all takes place to ensure a problem free switchgear replacement.

Following the implementation of Safe Systems of Work by the IUS Senior Authorised Person (SAP), oil filled Yorkshire Switchgear and Circuit Breakers are removed by our electrical fitters in conjunction with the IUS HIAB driver. A new Schneider Electric RN2C Ring Main Unit (RMU) is then installed in its place. The original switchgear is returned to NPg for recycling. The IUS electrical fitters secure the new RMU in place and make the necessary connections to the existing earthing system within the substation. The transformer 11kV compound filled box is replaced with a new ‘dry box’ unit, allowing for the installation and termination of 300mm triplex cable. This cable is installed from the jointing position, outside the substation, where it is straight jointed to the existing NPg 11kV network by the IUS cable jointers.

The IUS SAP completes the work via continuity, insulation resistance and pressure testing prior to the substation equipment being energised. All subsequent test results and hand back documentation is collated and returned to NPg for their records.

IUS deliver extensive low voltage (LV) OHL rebuild and refurbishment works, replacing NPg’s open wire network with Aerial Bundled Conductor (ABC) and changing rotten and defective poles where required. IUS also delivers LV OHL shrouding works for NPg, where protective shrouding is placed over exposed LV conductors to allow customers to have building and construction works completed in close proximity to the LV network. IUS exclusively deliver these works for NPg, managing the end-to-end process to strict customer service and guaranteed standard guidelines. In addition to these two core overhead line frameworks, IUS also deliver OHL inspection and remedial works for NPg, ensuring that their high-risk sites meet the necessary ESQCR standards required. IUS also deliver OHL earth tests and earth mat replacement works.

IUS is the sole deliverer of GM Automation works. On this framework, IUS instals actuators and Remote Telecontrol Units (RTU’s) in to existing NPg secondary substations. Once commissioned, these sites become automated, meaning that NPg’s Network Control Center can operate their switchgear remotely, improving restoration and response times for their customers in the event of network faults or damages. In addition, IUS also delivers GM HV substation maintenance and Fault Path Indicator (FPI) replacement works for NPg. Delivering this service, ensures that their HV network is kept up to standard and will operate as necessary when worked-upon or in the event of a fault or damage.

To deliver the above frameworks, IUS has an extensive direct team of Project Managers, Project Coordinators, Planners, Supervisors, SAP’s, AP’s, Fitters, Linesmen and Jointers. All of these staff are fully authorised to work and operate on NPg’s LV and HV overhead and underground electrical networks. They are all centrally managed, which assists with a consistent approach including efficient programming.