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  1. R

    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...
  2. 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...
  3. 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...
  4. 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
  5. 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...
  6. 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...
  7. 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...
  8. 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
  9. 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,
  10. 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...
  11. 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...
  12. 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...
  13. 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...
  14. R

    Domestic 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...
  15. 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...
  16. 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...
  17. 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...
  18. 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...
  19. 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...
  20. 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...
  21. 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...
  22. 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...
  23. 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...
  24. 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...
  25. G

    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...
  26. 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...
  27. 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...
  28. 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...
  29. 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...
  30. 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...
  31. CestLaGalere

    Finding infrequent RCD trip

    I have a new breaker panel fitted (March), mostly new appliances, and some from an existing house. The house is divided into 2 sections with an RCD for each, each section has a ring main and lighting as well as a couple of other breakers on it. One of the RCDs trips infrequently time between...
  32. DomB78

    TYPE C RCBO Fails to trip on 1 Times RCD Test

    Hi Can anyone help ? Recently fitted 2 separate Eaton 32a Type C RCBO, on the RCD test it fails to trip on the 1 times test and gives result as >400ms. It trips fine on 5 times test in 7.1ms. Using Megger 1552. They are fitted on 2 new 6m2 radial circuits with Blue commando sockets. IR results...
  33. W

    Timed outdoor lights trip..then they don't?

    Hi all, New to this forum. I have a weird scenario and wondered if anyone might be able to help. I have a Grasslin timer socket switch (not digital) in my garage. This powers 4x lights outside my house. I have 70 Watt bulbs in each. When they are set to come on, at 6pm, it trips the...
  34. Dave Jenkins

    Why are the RCD trip times for I and 5I 300ms and 40ms

    Is there any particular reason why the trip times for RCDs at I and 5I are the values they are (300ms and 40ms). Is there some particular medical reason why?? I'm just curious, no particular reason but may weave that into the conversation next time I'm in the pub!!
  35. littlespark

    What can cause an invertor to trip the MCB?

    When visiting my parents, I noticed their PV invertor was showing zero W generated. On inspection, I found the MCB had tripped. Is there any reason for an invertor to trip it? Powercut, or power surge? The PV system is rated 3kW, and the MCB is 20A, type C. We checked back the history on an app...
  36. D

    Deep fat fryer causing electric to trip

    I have a Tefal 1000 deep fat fryer. It is the first time I have used it. Was given as new a few years ago. I used the same outlet as I use for the kettle 2200w and a microwave 700w. The Tefal was on for around 30 seconds and it tripped the RCD in the house electric. Kettle works fine and also...
  37. S

    TT Ze reading- loop high or loop no trip?

    When measuring Ze on a TT that's RCD protected which is more accurate? Getting 27.1 on high current but 563 on no trip.
  38. A

    Oven Tripping, but only after use

    Hi, I'm new to the forum and to electrics in general, trying to study and get qualified and get practice where I can. One of my friends has asked me to help with his oven, which has been tripping the whole CU, but only after he's cooked in it and opens the door. Apparently someone looked at it...
  39. michaelw6

    commercial industrial zs mccb 3phase question TN-C-S.

    Im specking a large 480a cable over 160m ive done cable calcs and come up with 2x 120mm 70c armored. now Im trying to work out my max zs...with no avail. my main ze is 0.17 but my mccb is saying max zs of 0.054 and my mccb will not trip... why is it so low? its impossible to get my zs less than...
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