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  1. Pete999

    Trainee Earthing systems explained

  2. S

    SWA earthing

    I’ve seen debate in the past on here about whether to earth both ends of SWA at the glands even when using 3 core with a core as the cpc. My question is: If I gland the load end and earth the banjo there, then gland the supply end but run the 3 cores straight through the building skin so there...
  3. M

    Back box earthing

    Probably a bit of a noddy question but I am bringing my TV aerial cable into the house which I have already done. Now I want to fit a TV socket to the wall to tidy it all up. I have purchased a metal back box with a plastic TV coaxial faceplate. On the metal back box there is an adjustable lug...
  4. M

    Earthing an Outbuilding

    This is my first posting here - I am not an electrician so please bear with me. I am trying to establish the best method to provide earthing of a 60A supply to a new build garage / workshop to be taken from a domestic residence. The incoming supply to the house is TN-C-S with a supplementary...
  5. D

    Industrial Earthing arrangement

    Is anyone able to clarify with me how i can work out what earthing arrangement i have on site. Supply comes into one of our motor switch rooms from an 11kv to LV transformer located directly outside. I can see 4 big copper bars (3phases and neutral) coming in which will then feed off to the...
  6. L

    SWA gland earthing

    Hi all, Just having a chat with a customer who we do regular maintenance work for. They have had an extension and got another company in to do the electrics due to us not having the time. The main reason for the post is the installer has used self tapping screws on all the swa glands. Is there...
  7. M

    earthing system?

    having a slight disagreement with a maintenance guy on a job im testing... just a bit of banter, but can any confirm this earthing system..?!
  8. T

    Multiple distribution boards and earthing arrangements

    Hi all, first post, and it relates to quite a challenging installation. The short version is that I'm working through remedial work on a 75 page EICR on a site with 24 distribution boards, hit a very nasty C1, have resolved it, but now have max Zs issues that were actually there before but not...
  9. D

    Domestic Earthing a PV system question

    I am fitting up a small PV system on a porch roof using a small (Plug in Solar) 4 panel rig just would like to know if its lightning earth grounding wire can be threaded under tiles to emerge as required at its brackets (to be neater), or would it need to be topside. Figure there are rules for...
  10. L

    Earthing across flanges

    With regards to electrical continuity across pipe flanges to bs 7671 I cannot find anything on how to size flat braided cable. Could someone point me in the right direction please is there a rule of thumb with regards to bolt size? Thanks
  11. Zdb

    High integrity earthing

    Only time I've done this has been using the two separate CPCs of a RFC using different terminals inside the D.B as per 543.7.1.204 I've been asked to test a load of high integrity radial circuits with two separate (different sized) CPCs. My question is, in the box which asks for the CSA of the...
  12. S

    Hazardous areas - control voltage transformer earthing -

    I've been in an ongoing debate regarding earthing of a control transformer and i'd like some other opinions. 690 primary, 120v secondary supplying control circuits (contactors/DC convertors etc), the neutral is tied to earth - My issue is the location that it is tied to Earth. As far as I know...
  13. phillipdj

    Earthing to 1st floor flats

    Hi, I've come across this strange setup on a set of flats I'm doing work on and wondered what people think. There are 4 flats on the 1st and 2nd floor (ground floor is a shop) with their own supply from the street. The supply enters the building from underground at the bottom of the stairs, a...
  14. C

    Parallel generator, earthing and bonding

    Hello, can anyone advise on bonding of extraneous conductive parts when supply is from a generator run parallel with distribution network? There'll b a 200kva generator supplying spray booths that have a gas supply to them. The metal pipes aren't underground but connect to tanks outside sitting...
  15. EalingBadger

    The hoary old topic of PME, TN-C-S and earthing rods (not TT)

    Somewhere along the line I picked up a suggestion from a forum posting or two that the DNO does not like you to connect an earthing rod to his "earth" - even though it is effectively just creating yet another, local to your installation, earthing point for the multiple ones already assumed to...
  16. Gladius

    Faraday cage earthing.

    Hi there, We will need to earth a Faraday cage room in an experimental work, do we need to certify the job? Can it be only earthed into the plumbing pipes if available (Bonding?)? If there are no pipes around should we earth it into a mains circuit using a junction box or surface box for...
  17. E

    Earthing System Query

    Hi, just a quick question... I’m at the stage now where I’m being pretty nosey at other people’s consumer units/supply set ups etc to further improve my understanding and recognition of the different earthing systems found in domestic properties. The image below was taken at a member of my...
  18. Strima

    Main Earthing Conductor Termination with SPDs

    Here's a question that I was asked earlier. If you have SPDs installed in a DB is it permissible to terminate the main earthing conductor into the SPD first then the DB earth bar? Or must it be terminated in the DB earth bar first then the SPD?
  19. loplug

    TT earthing question

    I'm working on a Job where the earth is TT there is a sub main fed by 16mm twin and earth if I put a earth rod in at the submain position should I connect the cpc of the submain to the earth rod at the sub dB or just use it as a cpc and earth the sub board separately ?
  20. DAvid Prosser

    Earthing and protection course. EA Technology anyone been ?

    Hi, looking to broaden my knowledge regarding earthing and protection. EA Technology have been mentioned as having decent courses in this area. I would like to hear from anyone who has been on training with them even if not in this field as often a standard will run through most training...
  21. Gavin John Hyde

    Thoughts on this earthing at cut out.....

    On a job this evening just taking a look around and meeting customer as wants downstairs rewired. Only collecting keys before i go back and do a few tests and quote fully. Appears at sometime to have been TNS but changed to PME? Instead of earth and Neutral joining in the cut out. They are...
  22. T

    Earthing of Three phase Motor

    Hi recently was on a job carrying out EX inspections on three phase motor at a pharmaceutical plant. The supply cable going to the motors does not have a core for the earth they have used the braid/SWA of the cable for earthing. So entering the three phase motor with EXe cable glands terminating...
  23. M

    Catering van generator earthing ??

    Hi new here so take it easy chaps !! A client of mine wishes to supply their catering van from a new generator they are purchasing, I believe it is single phase 7.5kW Inverter style generator with a 32 amp socket outlet. My query is about the earthing to the van. The van has a DB inside with a...
  24. T

    Earthing Boss Question

    Hi just a question regarding the supplementary earthing in a hazardous area. When you have a earth boss welded to a piece of steel which is the structure of the building to give a bonding connection for equipment in that area they usually say that only two earth cables per earth boss. Is there...
  25. R

    Domestic New consumer unit on TT installation - earthing and SPD queries

    I'm going to replace the consumer unit for a customer in rural Oxfordshire. The supply comes in overhead, drops down a telegraph-type pole into the ground, and runs about 2m to a recessed box in the wall (perhaps coming up in the cavity). I can't find the earth rod - probably entirely...
  26. diyterry

    Domestic Earthing copper pipes .............

    While ripping the old bathroom fittings out I noticed that none of the pipework or fittings were earthed. Should they be earthed and if so what is the preferred method?
  27. D

    Earthing for 3 phase boards

    Hi just after opinions on this one got three 3 phase supplies all 25mm 4 core swa, armour not been used for earth would you run a seperate 16mm earth for each supply or just loop all the earths from 1 16mm all the supplies are right next to each other
  28. J

    SWA - earthing the steel wire?

    Hi I’m new to the forum & just a DIY’er! I’m running a 15m length of 2.5mm 3 core (twin & earth) SWA to our decking at the back of the garden for a double socket. Must the steel wire armour be earthed using the banjo or is the CPC core sufficient? Thanks in advance! J
  29. Flatmax

    Earthing a mouse/keyboard

    Hi all, I am an amateur and have been checking EF measurements around my house. The computer seems quite a large source and I'd like to reduce my exposure. Can a keyboard/mouse be earthed/grounded with a contact wire on the item running to Earth on socket/radiator? I thought of using an...
  30. C

    Domestic Earthing required? MR16 halogen to GU10 LED conversion

    Hello, I am converting my ceiling downlighters to LED. The old MR16 50W halogen bulbs come with a 12v transformer. I plan to cut the LV cable just before the transformer, then strip it and wire it into the new GU10 LED lamp holder. This means the new GU10 lamp holder will not be earthed. Looking...
  31. T

    Progress with DNO regards provision of earthing terminal, thoughts?

    Western Power Distribution - Information for electrical installers - https://www.westernpower.co.uk/connections-landing/connections-useful-information/information-for-electrical-installers I have been contacted today regards policy and methods regarding provision and maintenance of earthing in...
  32. E

    High Integrity Earthing

    Hi Guy's, Need your take on a commercial office IT environment. I am getting earth leakage total of 26mA, okay, spread over 22 workstations & 4 Server & ups IT devices, not bad. The power RFCircuits are fortunately spread over a split load board / 2 RCD's. No nuisance tripping reported. Subject...
  33. Andy-1960

    TN-S vs TNC-S (PNB) Earthing System

    What are the thoughts of you guys on the differences between a TN-S and a TNC-S (PNB) Earthing System. My understanding is as follows: TNC-S (PNB) - the Neutral & Earth Conductor are joined in the main switchboard with the neutral conductor between the transformer and the switchboard then...
  34. Alrebcon180

    Main 185mm earthing query

    Hi guys bit of knowledge needed.. Have a 2x185mm 3phase supply going to a panel board with 800amp main switch from a UK Power networks transformer about 15m away, also run with them a 185mm earth which goes to a earth bar next to the panel board where all the outgoing swa earth overlays are...
  35. T

    Main earthing Conductor also bonds water

    Domestic TNCS, main earthing conductor runs to water pipe, bonds via clamp with label, cable is continuous, then runs on to MET in DB. Seems wrong, but cant find specific reg to say so....any thoughts? Thanks, Timotei
  36. B

    Caravan park Earthing

    Is TNS permitted on caravan site? I always thought you could use as TNS as supply cable then TT each pitch, spark I’m working with says you can use TNS all way through if ZS is acceptable Thanks
  37. S

    Spiritual Earthing..

    OK, so this isn't really my thing, it's more my partners. She's really into all things spiritual and she came across this technique known as Spiritual Earthing(or Grounding) which I thought was quite intriguing and may have some scientific merit to it. I don't fully understand the process but I...
  38. P

    High Zs on SWA Armour / New Earthing Conductor

    Hi all I am after some help/Advice if possible please A SWA sub main Distribution circuit has been given a Code 2 Rating on a recent EICR due to a high Zs of 2.8 ohms. The cable is 180 metres long and runs underground in ducting. The Install is from a few years ago when a new Substation was put...
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