Changes to DSR Procedures 2018/1 Bulletin number HSS 406 OB 160 Changes to DSR Procedures 2018/1 Dudley Sparks

You said – We did Excavating in a Secondary Substation Background to this change: There was a request from the business, through the Operational SAT, to allow staff with the competency “Carry out Excavation Activity Only” to excavate in a secondary substation without a Limitation of Access. With the current procedures in place (DSR 01 001 and DSR 01 014) it is unclear whether this is possible due to there being no definition of “electrical competency”. In 2008, HSS 406 OB 55 was issued following three incidents of HV cable damages whilst excavating in or around our substations. This went on to be incorporated into DSR 01 014. After looking at the current training for this competency, checking the risk assessment and revisiting the original bulletin we agreed to the following changes. Operational Safety Team DSR 01 014 - Excavating Near Electricity Cables DSR 01 014 8.6.1 – clarification. Electrical Competency is defined as being eligible to hold a copy of the DSRs as per DSR 01 001. Note: text in red and underlined is additional to the current version of DSR 01 014. You said – We did DSR 01 001 – Issue of DSRs DSR 01 001 Appendix A – eligibility for DSRs A person with the competency “Carry Out Excavation Only” regardless of other competencies held is now eligible to hold a copy of the DSRs. This means, in conjunction with the clarification above, that when excavating in a secondary substation, a Limitation of Access (LoA) is only required if the technically competent person putting the person to work considers it necessary..

Tree cutting & DSRs Staff with “Tree Cutting Near Overhead Line Systems” now require a set of DSRs regardless of any other competencies they hold.

DSR 01 015 - Identification of Points of Work It has been noted that on some types of early SF6 RMUs the gas circuit breaker (GCB) will trip on low gas and cannot be reclosed without re-gassing. Where the unit is being replaced, to prevent having to re-gas in order to comply DSR 01 015 as it stands, a method has been added (new section 8.2.2).

DSR 01 016 - How to Ensure Low Voltage Customers Have Correct Polarity and Phase Rotation The following procedure (which must be read as part of DSR 01 016 section 7.2) gives guidance when a cross polarity is discovered by a person working alone.

DSR 01 018 Identification of LV Cables The changes are due to the issue of HSS 40 059 (Identification of Neutral Conductor on LV Underground Cables). Section 8.4.1 Positive Electrical Identification using an Approved Signal Device 1st paragraph has been reworded regarding the use of new LV cable identifiers.

DSR 01 020 – Connecting Cables to LV Boards This change will affect relevant staff working in the LPN licence area With immediate effect, the permission to issue a Limitation of Access (LoA) safety document for work on the LV tails of a distribution transformer when an isolated circuit breaker is used as a point of isolation on the HV side of the transformer has ceased and a Permit to Work (PTW) shall be issued. There are also some additional requirements to aid the auditing process. Please see procedure for details.

General notes about these changes The DSR procedures on the intranet have been updated A new wire bound DSR procedure book will be re-issued in due course If you are DSR holder This bulletin constitutes part of the approved procedures and must be kept with your DSR procedures Mark in your DSR procedures book where the changes have been made Any further questions? Please refer to one of the members of the Operational Safety Team Thank you