disconnection | Page 5

disconnection

Recent contents View information Top users
  1. S

    Disconnection time on TT system

    Can a Sunnyboy SB3800 inverter disconnect on a TT system fast enough to prevent injury through shock? The installation has an RCD fitted and the inverter is connected to a 16 amp MCB. With the inverter having simple separation, does this negate the need for an RCD to protect the cable...
  2. D

    Max disconnection time

    hi lads i have few questions: what is max disconnection time for site hut lighting on a construction site ? max disconnection time for 110 V reduced low-voltage system ? reasons for the use of a 20 mA RCD ? Thanks for your fast reply!
  3. S

    disconnection times

    Hi Guys, Wonder if any of you could try and explain to me if the reason for disconnection times for fuses /proctective devices etc. As on one hand, i was told at college it is to protect the cable from catching fire etc, and then iget the impression the reason for having say 0.4 disconnection...
  4. J

    Shed Installation Disconnection time?

    Hi I have a socket Radial off a 20A MCB and a lighting Radial off 6A MCB in a shed the board is fed by a 32amp MCB protected by an RCD on a TNCS syatem in the house. If I want the first point of fault ie the shed to trip first should I be using an RCBO for a TT system that trips under .2s? This...
  5. B

    Disconnection Times

    I've always wondered why BS7671 states that a disconnection time of 0.4s is required for circuits NOT exceeding 32A and for circuits exceeding 32A it is 5s Surely you would want the higher current to trip quicker? Can someone clarify this?
  6. W

    TT System and 30mA RCD tripping times

    Help! Sorry having a bad day. I understand the concept behind touch contact of 50v and the above 1666 ohms. But when physically testing with 17th ed dilog and testing a TT system 30mA RCD. At 1x and 5X what reading would you see on your meter? or would you just test the mechanical aspect...
  7. J

    Disconnection times

    Hello all I no the disconnection times for TN circuits are 0.4s for final ccts with an (in) not exceedind 32A AND 5 s for final circuits exceeding 32A Distrubution ccts I have just installated some lights within a industrial building in a riser and have tested all came back ok just have...
  8. T

    Disconnection Times

    Hi all, Just got a query regarding what values to use from the Red Book 32a Ring Main Domestic Circuit. Do I use the 0.4s Disconnection times or the 5s Disconnection times? regards Tom
  9. J

    Disconnection Times

    Am l right in thinking that its 0.4 seconds for under 32A and upto 5 seconds for anything 32A and above? If so why is that? :confused:
  10. S

    PIR Question

    My uncle wants his property tested as theres a new tennant going to be moving in and just by looking at it i can see its only his sockets that have rcd protection, shower etc don't. What code does this go down as on test sheet and do they have to be changed so that all circuits are rcd...
  11. S

    Part P Assessment ... disconnection time of an S Type Circuit Breaker w/ timed relay.

    Just had my Part P Assessment (and passed!) :) Although I was asked one question particulat question ... so Stuart, whats the disconnection time of an S Type Circuit Breaker with timed relay. My jaw and other parts of my body hit the floor! Funny thing is after I tried for 5 mins, he couldnt...
  12. O

    Help with PIR

    Hi Needing help with a PIR. 1. Old wylex type 2 CBs what BS is this an what Ka rating does it have. 2. MEM Memway 3 phase DB with rewireable fuses i take it they are a BS3036 3.The Memway is fed via an 60A TPN switch fuse Oterail make would this have a BS No 4. Method of protection on PIR...
  13. D

    Cooker Disconnection Time

    Cooker 30A I assume the disconnection time is 0.4 seconds, even though the outlet does not have a socket. Only circuits for distribution above 32A are 5 sec. Ta New comer:)
  14. H

    Is there any point testing earth loop impedance

    In a tt system? The earth spike is Reading greater than 50 ohms so clearly the mcbs won't make their rated disconnection times. Waste of time?
  15. albi

    315amp fuse max Zs

    does any one know the max Zs permitted for a 315Amp BS88 fuse got brain freeze know on page 45 of periodic report :mad:
  16. A

    16th Edition and RCDs?

    Can anyone give me a quick answer on whether or not the 16th Edition permitted the non-use of RCDs for additional protection? I've just had a call from a woman buying a house and she's described the consumer unit as having one rcd protecting cooker, shower and two socket circuits, but three...
  17. P

    schedule of inspections/supplementary bonding

    On page 3 of schedule of inspections (where you put a tick, X or N/A in the boxes), presence of supplementary bonding conductors appears twice - once in fault protection 1) automatic disconnection of supply and again near the bottom of the page under Additional protection. Have looked in the...
  18. P

    Domestic

    Guys don't have my big read book handy at mo can you answer the following 1. 32amp circuit were protective measure against electric shock is ads is the maximum disconnection time permitted by bs 7671 = 0.5s 2. maximum Zs permitted by bs7671 for a 32amp circuit 3. What is the bs(en)...
  19. W

    disconnection

    when filling in test sheets can you still put eebads or do you use ados
  20. D

    disconnection times

    would someone please explain the reasons for having a 0.4 second disconnection time and a 5 second disconnection time, why is there a big difference between the two readings :confused:

OFFICIAL SPONSORS

Electrical Goods - Electrical Tools - Brand Names Electrician Courses Green Electrical Goods PCB Way Electrical Goods - Electrical Tools - Brand Names Pushfit Wire Connectors Electric Underfloor Heating Electrician Courses
These Official Forum Sponsors May Provide Discounts to Regular Forum Members - If you would like to sponsor us then CLICK HERE and post a thread with who you are, and we'll send you some stats etc

YOUR Unread Posts

This website was designed, optimised and is hosted by untold.media Operating under the name Untold Media since 2001.
Back
Top