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  1. M

    RCBO trip.

    Got a large rewire ongoing at the minute. Owner wants to use current sockets alongside the new board as he’s living in one part of the house whilst the builders are in. Today the old supply was disconnected and whilst cutting through an old cable not connected to any of my new legs the RCBO...
  2. B

    Rcd trip times help

    Hi have 60947-2 Main Switch with added 61008 with settings for mA and mS, now come to test and it’s set on 300mA with delay of 0.5 so 500ms, now what I’m wanting to know is: 500ms is the maximum tripping time for a S type RCD, so what’s the point in having more settings as this has a variable...
  3. B

    RCD trip times

    Hi have 60947-2 Main Switch with added 61008 with settings for mA and mS, now come to test and it’s set on 300mA with delay of 0.5 so 500ms, now what I’m wanting to know is: 500ms is the maximum tripping time for a S type RCD, so what’s the point in having more settings as this has a variable...
  4. C

    RCD trip time

    What are the required RCD trip time requirements? And what do you typically see in the real world?
  5. E

    Why would the Main breaker trip?

    I recently installed a photovoltaic solar system for a customer but there seems to be a problem with on of the breakers. Here is a bit of context: The panelboard is a 100A main/125A bus 3ph 480V. The sum of the breakers is 120A (30,30,30,15,15) and each breaker is connected to an inverter. What...
  6. B

    UK Oven trip MCB

    Hi all, I’m hoping someone will be able to give me some advice on my oven. Tonight I had both ovens on (as has been done on several occasions). When I went into the kitchen about 10 minutes later I noticed the oven was off and had tripped the 32Amp MCB. I reset it at the CU and it came back on...
  7. M

    Outside Lights trip RCD

    Hi All, I was wondering if anyone could help me with a recent problem I’ve had on a job. About 5 months ago I installed about 5 outdoor soffit lights from switch inside. All worked perfectly and customer was happy. I’ve recently been called back to the job as the outdoor lights have been...
  8. B

    UK RCD vs MCB trip

    Evening everybody, I’m wondering if someone wouldn’t mind answering a question for me about RCDs. I had a water pipe burst behind my washing machine this evening, and once I’d isolated the leak I noticed the sockets had tripped. When I went to reset the breaker, I noticed that it was the RCD...
  9. K

    Protection against open/loose neutral?

    Hello friends, is there such a thing as a "smart meter" that I can install on my backwoods house that will trip if it detects a loose/open neutral? If so, where can I get one? Thanks very much
  10. N

    Why would spike lights trip an MCB as if a dead short is present ?

    Just finished installing 20 x spike lights in a customers front garden. 2.5mm SWA ran from existing junction box feeding existing fence lights. All pulling no where near 1A in total. When all connected and wiring tested, went to switch on MCB and it popped. Rendering the MCB useless as if L-N...
  11. RutlandFox

    Modern wiring help rcd trip

    Hi all. Newbie please be gentle... My daughter in law moved into a new [2007] build. All socket circuits 20A radial MCB. One socket circuit trips rcd intermittently when the Wi-Fi router psu plugged in. Psu is double insulated and pat tests ok. Radial tests out ok with 50M ohm at 500v. Nothing...
  12. M

    Intermittent mcb trip electric gate

    Hi, just registered, I qualified in 1973 and and not done much electical work for the past 30 odd years but I obviously have grasp of the theory. I have an intermittent mcb tripping on my electric gate, which I installed. (All electric no hydraulics) The mcb will trip in any weather...
  13. J

    Am I liable to pay

    I rent a property in the UK. All of the sockets in my house were tripping, even when all sockets were switched off. An electrician came out, sent by the estate agent who manages the property. They determined it was an appliance of mine that tripped the power. He said something about why the...
  14. B

    RCD trip time greater than 300ms

    Got sent this, RCD Failed x1 greater than 300ms maybe if they changed the supply at top of RCD, currently have neutral on the left and line in the right , also the RCD is fed from 63Amp MCB is that all good just feeding an RCBO 30ma board
  15. M

    Square D rcd wont trip with my tester

    Hi guys wondering If anyone can shed some light either through knowledge or experience of the same problem. I have a Megger MFT 1731. Whenever I come to square D type rcds my tester doesn't trip them. I try it on doing the manual settings for 1x and 5x and even the auto. Ramp tests won't...
  16. B

    RCD won’t trip help needed

    TT system, have upfront 60947-2 with added on 61008 with mA and ms settings, now I’m getting Zdb of 22.9 ohms and Ka of 4.0, now the RCD can be what ever I set it to but I’m struggling, I’ve set it to 300ma and 300ms but can’t seem to get it to trip? I also have a split phase supply so have L1...
  17. spud1

    Can I calculate how fast an RCD should trip?

    Hi all. Been bugging me. I think there is a way to calculate how fast a particularly rated RCD should trip (rather than measuring) but I can't remember how to do it ? e. g. If I was designing an SWA submain fed from a TT earthed installation and I needed to install say a 300mA TD RCD to...
  18. A

    difference between zi no trip and zi trip

    hi everyone, i have just got the fluke 1664fc can somone please tell me the difference between a zi no trip test and a zi trip test. i know that it in zi trip it is a high current test but still i can not understand why im getting different readings between live and earth. Thanks
  19. S

    Well, that was a short trip

    Just back from Nairobi errr business trip cut short, looking at my "holiday" vids I need to loose a bit of weight........ anyways got to sort out my holiday cleaning...... sand gets everywhere,
  20. spud1

    Which RCD trip time to record?

    Afternoon all, As we all know the new 18th certs only have the facility to record the x1 trip time of a circuits RCD in the test results page. They've got rid of the x5 column for some reason!? NICEIC are recommending that where the RCD is being used for additional protection the x5 reading...
  21. T

    Board change (RCBOs) Lights trip sockets

    Evening all, I changed a board today in a ground floor flat. 3 circuits with separate RCBOs (Shower 40A, sockets 32A, and Lights 6A) Switching on any light switch causes the both RCBOs for the lights and sockets to trip. Insulation resistance results are in the 100s between conductors on...
  22. P

    Led strip light off, kitchen cabinets

    hi there, If anyone could help. We have blue led strip lighting under and over our kitchen cabinets, after a few days of moving in some of the lighting went off. I’ve looked under the cabinet and found the attached photo. 1) I it wired properly? 2) how comes the yellow and green wire is...
  23. G

    Breaker trip after screwing light fitting back to freshly painted ceiling

    Hi, This afternoon, finished re-emulsioning a plasterboard ceiling in a 25-y-o house (so the electrics are modern enough). I had removed a circular metal light fitting - the swivel 3-spotlight type of thing - but it uses modern LED bulbs. Never ever had a problem with it. The wiring is solidly...
  24. R

    Electrician RCBO trip test query - Testing wrong or is there a fault?

    Hi, Can anyone please explain why my friend's 30mA trip RCBOs passes the trip test (e.g. x5 is less than 40ms) when the test is done at the consumer unit but fails when the test is done at the sockets. Is he doing something wrong or is there a fault somewhere (the RCBO or the circuit...
  25. S

    Washing machine trip the breaker.

    When my washing machine (7 year old ) was running yesterday it trip the breaker ( that one ,first on the left , RCD i guess?!) and no power in home. We reset the trip and the same happened twice more (took me a ittle while to realise it was the washing machine!). The socket is OK, and I presume...
  26. Marti

    Random RCD trip & interconnected circuits. Suggestions appreciated.

    Hi There, I was called out to a house RCD trip which would not reset. An old style 10 way split board with a single 30 ma RCD (half without RCD protection). RCD checks out fine but I found a faulty chandelier & replaced it with a single bulb for now. Also a faulty 12v transformer flickering; now...
  27. Tallman

    Domestic Spur circuit cutting out then restoring - no RCD trip

    This is a new one to me.. a small spur circuit (3 double sockets) on ground floor, several small load items connected - table lamp, assorted AV kit (TV, Amp, DVD). On just these 3 sockets only, the power cuts, sometimes flicking on - off - on again. Other times it'll stay off for 1-3 minutes...
  28. A

    Fault finding an intermittent RCD trip

    Hey all, really hopping someone will be able to help me with my issue. This problem relates to my personal home, but i can't seem to figure out the issue. Quick background. The main switchboard at my house feeds into a sub-board in my shed. This sub-board then feeds into another sub-board which...
  29. F

    Random socket tripping

    Hi, Our breaker box is located in the cellar. We experience random socket trips throughout the year. Summertime seems to be the best when we can go months without an issue. Autumn/winter time is awful. We have had 3 trips within the last 24 hours. No new appliance has been switched on when the...
  30. Stephen

    New electric cooker causing power to trip at fuse. The fuse is reluctant to flick back on after.

    Hi all. Thank you all in advance for your help and advice. I was hoping to get some help and advice on a cooker issue I'm experiencing. My cooker is "brand new" and I recently had it installed by my father inlaw (competent tradesman although not an electrician) The cooker is brand new but...
  31. M

    Fault finding an intermittent RCD trip.

    Hi all, I’ve had a headache of a fault and can’t think what to do next. The house has an RCD main switch, and I’ve verified the circuit which has the fault to be the kitchen ring final. The RCD has tripped once without interference, and several times when a switched fuse spur is turned on...
  32. T

    BG RCBO ramp test on one of them shows trip at 15ma every other one is 24 ma

    So just did an EICR few problems mostly rectified. Customer wanted new CU so put in BG with RCBO just five circuits. Tests on EICR were fine except for high ohms on Zs for lighting first floor so tracking that down. All RCBO are fine except this one 32a ring final circuit. RFC tests all fine IR...
  33. A

    Shunt trip in a domestic CU? Looking for a complaint way of remotely switching off power

    Hi. A thought of a domestic fire in my house terrifies me, so I installed a really sophisticated fire alarm in my house. This system optionally can even turn off the gas valve (it has a motorized arm which is installed on the main valve) and switch off electricity in case if the fire is detected...
  34. T

    RCBO trip when cabinet lights switch on

    Call out for tripped 20A RCBO on TT system, 3 Halolite T4 fluorescent cabinet lights (class 2) on 3A FCU from radial socket circuit, trips occasionally when lights are switched on. Circuit tested including IR, all results good, RCBO tested including ramp test, all good. Connections checked...
  35. GBDamo

    Will a B type 32 trip before a C type 16?

    Morening all, I have a dilema that you may be able to help with. Manufacturers instructions ask for the unit to be fed from a C Type 16Amp MCB. At the moment this is all the technical information I have. In one in twenty cases they experience nuisance tripping and have now recommended fitting...
  36. D

    Both RCD's trip randomly

    Scratching my head a bit on a job today. Been to clients house to investigate fault with installation. For the past few months client has reported that both RCD's on his dual RCD board have tripped at the same time on odd occasions thus losing all power to house. House was rewired by another...
  37. M

    RCD trip across board

    I am a relatively newly qualified electrician and have completed a re-wire but come across a problem i dont understand. I have a dual board with a lighting and a power circuit on each side. On the right side the power and lighting is entirely stable, but whenever a load is applied to the...
  38. Pete999

    One for Gavin, a trip back in time

    Gavin, Milsom Steet, still there I hope. My old Boss when I was a Lad, had the contract to provide Christmas decorations on the shops and businesses on the whole length of the street. Used to string TRS twin from building to building, using ladders, no Cherry pickers in those days, men where men...
  39. D

    Unsure of trip switches on fuse box?

    Hey folks I'm in a bit of a pickle right now, the new house we moved into has this: what is this switch with the FG on it? when I flip it up it just comes back down again, won't stay up.. all the plug sockets in the walls are dead at the moment so I'm guessing this is the key to getting them...
  40. satori

    Turn off hob and both MCB and RCD trip.

    Parents in law are experiencing and intermittent fault. Occasionally, when one of the rings on the hob (I think the hob is of the induction type) is turned off, both the hob MCB and the associated RCD trip. I can't envisage a fault that would trip both. The property is a bungalow that had an...
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