Firstly I'd like to take this opportunity to wish our Clients, friends, students and Blog subscribers SEASONAL GREETINGS and a very prosperous New Year.
I'm actually in Gibraltar writing this post completing a personal goal of mine. That's topping up my sailing qualifications in preparation for my exciting challenge later next year to the Souther Ocean competing in the Clipper Round the World Race (more on that next year).
Well, 2018 again was an exciting year for the team GreyMatters. So, at the end of 2017, we set our usual goals on what we wanted to achieve in 2018. The biggest success story which is probably closest to my heart is smashing the previous year's lives-protected by our HV Earthing/Grounding Design services. (We shared how we calculated "Lives Saved" in this post)
One Goal accomplished this year I'm particularly proud of is the launch of the much requested GreyMattersGlobal.Academy The Academy is an Online learning portal where we have currently published and "Introduction to Earthing/Grounding Online Course". If you haven't had the opportunity to check-out the Academy yet here's a link to a Free Trial Offer.
Top 5 Posts of 2018
Here's a recap (incase you may have missed them) of the 5 Top post of 2018.
November 2018 Earthing Standards Update (Rail)
For the past few years. GreyMatters has been fortunate enough to support the rail electrification and upgrade programmes across the UK for Earthing Design. And maintaining a consistent approach across a building programme of this scale can be a massive engineering headache for all design teams concerned.
Especially, when Earthing Standards touches on so many disciplines along the way - from civils, OLE (Overhead line equipment), signals, EMC, 3rd parties, ecologies, geophysical as well as the more obvious general E&B (earthing and bonding). Full post here.
How to Size High Voltage Earthing Conductors Correctly
What size conductors should I use? And, is there a simple table I can use for this high voltage earthing design? These are great questions that I'm often asked. This post answers these questions together with the choice of conductor materials and jointing method within a high voltage earthing design project.
Assessing conductor size is entirely dependent on the electrical configuration and the load that the conductor must take. For example, an above-ground bonding conductor serves to transfer current with minimal voltage drop, from A to B. A directly buried conductor has an additional purpose, that of leaking the fault current/voltage into the local geology (as part of an electrode).
When considering Lightning, the same conductor above might also see a high-frequency component and which will impose yet another requirement. Full post.
What's the Difference between Earthing and Bonding?
What's the difference between earthing and bonding? That's a question our readers and clients ask often. Also, we're asked quite a bit about earthing and bonding in general. So, there’s an unusually large amount of confusion around the term Earthing and Bonding. Or, for our friends in the states; you might come across the term grounding and bonding.
Therefore, in this piece, I aim to clarify the difference between - what is Earthing and what is bonding and whether there is a difference. Read more...
Avoid death by PowerPoint - earthing system design demystified
It's a disconcerting feeling being ‘out of your depth’ or not even in the right ballpark. How are you going to save face?… I know, nod a few times in the right places and maybe ask an open question back, or better still, side-swipe it to a colleague; “what do you think, Stan?” - then run away and hope no-one notices. Did it work? Yes, phew!
Rise of Earth Potential (RoEP) | Know the Risks
Awareness of step and touch potential, caused by a rise of earth potential, is essential for anyone working on high-voltage power transmission and distribution systems above 1 kV.
A rise of earth potential
A rise of earth potential is caused by electrical faults that occur at electrical substations, power plants, or high-voltage transmission lines. Therefore short-circuit current flows through the plant structure and equipment and into the earthing electrode. Since the Soil Resistivity is not zero, any current injected into the earth at the earth electrode produces a 'Rise of Earth Potential'. This earth potential rise (EPR) is concerning an infinitely distant reference point. The resulting rise of earth potential can cause hazardous voltage, many hundreds of metres away from the actual fault location. Many factors determine the level of hazard, including available fault current, soil type, soil moisture, temperature, underlying rock layers, and clearing time to interrupt the fault. More...