Protection policy and witness testing

We said we would review our protection policy and confirm our position on third party witness testing.

“UKPN, SSE + WPD much more fexible about witness test requirements on smaller scale generaton projects (<200kW). SSE have ‘preferred installer’ DB where once they have tested a few and sure of competence don’t require WT except on major HV / utlity scale projects in MW (as opposed to up to 250kW). Think this is good idea.” 
Rachel Wood, Lark Energy Commercial.

During our Customer Connections Forums in November 2015, a customer from Lark Energy Commercial asked us whether we could be more flexible in our approach to witness testing for small-scale generation projects and permit third parties to act on behalf of the DNO to carry out the witness testing. We therefore committed to a full review of our protection policy and witness testing procedures in order to fully address the customer’s questions.

Witness testing is the name given to the process whereby our engineers meet with our connection customers and observe the protection systems associated their on-site generators. Commissioning engineers working on behalf of the customer will typically test the system with our engineers in attendance so we can observe and ensure that the generator is operating correctly.

Following a comprehensive review of our policy, we reached the conclusion that it would not be possible for us to allow third parties to carry out witness testing on our behalf. Our current policy for witness testing is in line with national guidance as documented in G59/3-2 2015 and moving away from this best-practice document would not be in the interests of our customers.

Our team presented the findings of this review at our Connections Customer Forum in November 2016 and answered questions from delegates to reaffirm how and why this decision was reached. This presentation was also published on our website to be fully accessible for any of our connections customers that want to look through the findings in further detail.

We will continue to review the policy every three years in line with our internal policies and will also re-evaluate on an ad-hoc basis if there are any significant changes in best-practice guidance for the industry.

• Northern Powergrid Policy for the Protection of Distribution Networks
• Update from our Connections Customer Forum in November 2016.