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  1. G

    Disconnection times, some clarification

    Evening, just revising for 18th update course and wondered if someone can just clarify something. (I might just be confusing myself, too long staring at the BBB) Reg 411.3.2.2 ii) does that also include luminaries? I understand 411.3.4 applies. Do notes 1 & 2 of 411.4.4 mean that the use of an...
  2. Pretty Mouth

    Short circuit disconnection times

    Could someone shed some light on the following please? 411.3.2.1 implies that the 5s / 0.4s disconnection times only apply to earth faults. I've not found anything else in the regs that suggests they apply to short circuits. 435.5.2 says faults should be disconnected before the fault current...
  3. S

    RCD disconnection times on 2018 forms

    Evening all, happy Friday! On the new forms there is only one column for RCD disconnection times. I understood you would just record the highest of the 5x readings but on looking around to confirm I found this article on Professional-Electrician: "The model forms in Appendix 6 have been...
  4. C

    Commercial Max disconection times

    Having a debate on site as to disconection times on a TN system, does the 18 addition say 0.4 up to 32amp and 5 after and 5 for distribution circuits?
  5. M

    air bag light comes on at strange times

    My niece has a 2004 Mazda Tribute with a strange air bag light problem. She can make a 40 mile round trip without the light coming on if there are no high load devices on, but if she turns on the heater or lights the air bag light comes on a few seconds later. To me this means the problem is due...
  6. J

    Domestic Changes to the requirements on recording RCD disconnection times

    Hi everyone, long term visitor to the forum but first time posting a question... be gentle This question is with regards to the changes to the 18th edition certificates, which only require one disconnection time recorded. When recording the highest value taken when carry out RCD tests, Reg...
  7. Blehstor

    Tachometer reading four times as normal

    Hello everyone. I installed a new instruments panel with a tachometer for my old car (Fiat Uno) the board is for a Fiat Palio but the connections are the same and the panel fits perfectly. The only problem is the tachometer, it displays 4000 rpm when the car is turned on but idle, and goes all...
  8. happyhippydad

    Tripping times for a 100mA RCD?

    Could anyone confirm if we test 100mA RCD's at x5? There is a lot of information on the web that says you only test at x1 but Table 3a in appendix 3 clearly shows a max disconnection time for a 100mA RCD at x5 to be 40ms. Thanks all.
  9. a-z electrics

    Car chargers coming...

    Bought a new little Cudis metal DB the other day.. on the circuit labels they now have CAR CHARGER.. the first of many I'm thinking! Have many sparks fitted any of these yet and what have been your experiences? I've done one for myself, just like a new cooker circuit really. I believe the...
  10. R

    Disconnection times for finals

    Just received a completed test sheet from an installer on a TN system with the max permitted disconnection time column filled in for the lighting circuit and 20A heater circuit as 5secs, surely 0.4
  11. P

    Disconnection times help

    Hi all just a little bit of advice at the company i work has just had a condition report done and they have marked down excessive zs for a 63a type d breaker but they have put it at 0.4 disconnection time it is a permanent fixed compressor I thought this would have been 5 sec it also has a b.s...
  12. John Lundrigan

    I'm confused about Type C Breaker Disconnection Times

    Hi All, When I consult Table 41.3 for a Type C Breaker rated 16A I see s max Zs of 1.37 Ohms. However this value is defined for both a 0.4s AND 5s disconnection time. This is obviously correct so I am missing something. Fig 3A5 also shows the table 0.1s to 5s. Can anyone explain please...
  13. haptism

    RCD testing times BYB vs OSG

    Happy new year folks; just been looking at trip times as i need a photocopy for a client. Anyhow, in the OSG (page 112) for a general RCD, it states "with a leakage current of 100% the device should open in less than 200ms". However in the BYB (Table 3A, page 318) the table says device should...
  14. 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...
  15. 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!!
  16. Vortigern

    Just had to post this! Western power replace main fuse twice and it popped both times

    Called to inspect power completely off. As title suggests main fuse had popped and DNO said call an electrician. You will not believe this job! The boxes are rotting away. The cables full of verdigree and corrosion. Soaking wet. All at a chinese take away. The cellar has no light. The only way...
  17. Pete999

    Workwear how times have changed, what do you wear to work?

    Just harping back to when I started, herringbone jacket, flannel shirt with matching tie, bib and brace overalls an polished shoes, bits of bog paper stuck to your face where you cut yourself shaving in cold water, catch the bus, get to the office to find out what your next job was, none of this...
  18. Gawa

    Newbie from South Africa

    Hello everyone. Just a heads up, English is not my native language. I rely heavily on the the spellchecker to help me correct my words. So some of the words may not have the meaning that I intended. I am from South Africa, a white male, 44 years old and one of an identical twin (we shared one...
  19. Lou

    Marks Electrical Services

    Marks Electrical Services offer a complete service in both domestic and commercial sectors in Cambridge and the surrounding areas. Run by Dean Marks, a Cambridge man with 20 years of experience, Marks Electrical Services will undertake to provide quality workmanship that you can trust. We pride...
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