RJ Power North were invited by Calor Gas to participate in a tender process for a new 11kV substation upgrade project on their site. A pre site visit and meeting was conducted by our business development and operations team. All associated project documentations and site notes were collated, and a Tender document submitted.
Following the project being awarded to RJ Power North another site visit and meeting was conducted by our Senior Authorised Person & Project Manager who were identified to deliver the project, Final checks and associated paperwork for procurement of equipment and materials were produced. Risk assessments and method statements were produced and forwarded across to our client for approval of works with detailed methodology of work plans.
Scope of Works:
The project was completed over 5 working days across two phases.
Phase one of the project was to install the new HV Transformer on to a new formed raised concrete bunded plinth located externally to the 11kV substation. The new 11kV switchgear was installed and mounted on to a raised steel structure within the 11kV substation.
A Cable containment system was installed to allow new HV & LV cable routes to be accomplished. All associated Protection Testing and Commissioning of the new 11kV switchgear and associated 800kVA Transformer were completed post installation of cabling. New earthing matrix and earth bonding was completed, and safety critical tripping circuits were first fixed ready for phase two of the project for final connections and commissioning testing.
New HV & LV cables were installed and tested as part of the scope of work and further civil works completed to reveal the main HV incoming cable that supplied existing HV substation that was due to be disconnected and cut away off system. This work was in preparation for phase two of the project.
Phase two of the project was booked in out of hours so the existing substation could be shut down for the day whilst the rest of the works could be completed, this was all agreed with the client at planning stages.
The mains power to the existing substation was isolated locally from the client’s main intake substation. The RJ Power SAP completed all associated safety documentation and also completed cable identification testing and spiking procedures of the incoming HV cable ready for jointing. Also, existing HV apparatus and cabling was proved dead at points of work following safe working zone procedures, so existing apparatus could be disconnected and cut away off the system. The scope of works required the existing apparatus to be disconnected and made safe off system only as the client organised for the apparatus to be collected and recycled at a later date.
The LV cables from the existing transformer onsite were disconnected and removed from the clients main LV switchboard, and new LV cables from the new HV transformer were installed and connected into the existing LV switchboard. The existing HV incoming cable from main intake substation was prepared and a HV straight joint completed to provide new HV connection in to new HV substation switchgear.
The second fix of earthing matrix and earth bonding was then completed along with final connections of safety critical tripping circuits. Post installation commissioning testing was completed to test full integrity of new HV/LV system installed. The redundant HV switchgear and HV transformer were marked up and identified as out of service and off system and made safe for client to remove at later date.
The HV and LV system was then restored and post installation checks and testing was completed to confirm that the site network was healthy with no issues and was in back to normal service position.
Full onsite reports of the works were completed and forwarded back to the RJ Power office for final O&M project report to be completed and sent across to the client.
The RJ Power Engineering team that delivered the works consisted of: 1 x Senior Authorised Person, 1 x Protection Engineer, 1 X Electrical Fitter team (Fitter & Fitters mate), 1 x HV Jointer team (HV Jointer & Jointers mate)
Challenges and Solutions:
The main challenges of this projects were:
- Site Conditions- Due to the site containing a vast amount of gas, the RJ Power engineers had to surrender their mobiles phones which made communication between the onsite team and the operation office support a challenge. To overcome this issue, we implemented keeping in touch calls during certain times of the day where the engineers had to leave the site and make the necessary calls to ensure consistency of communication.
- Test access facilities- The current switchgear located at the main intake and adjacent substation that was being removed off system did not have the relevant test bushings located at the substations. Procurement of these test bushings was difficult as there was a limited amount available to hire due to the switchgear now being obsolete. The onsite engineering team managed to come up with a solution to this issue and safely managed to carry out all testing that was required.
- Civils- Civils works was also highlighted as a slight issue onsite due to the foundations of the building where the cable runs were supposed to be routed and where the joint excavation was located. Due to the foundations being old and signs of crumbling when completing trial excavations, it was decided that a cable containment system would be installed. This was also the case within the 11kV substation, instead of digging out and creating new cable trenches a cable containment system was installed and steel structure was manufactured for the 11kV switchgear to be mounted on to get the satisfactory height for terminating the new HV cables in to. With this in place we also managed to save costs for our client and keep the project timetable on schedule.