hey guys....
ive downloaded some revision questions for my 2394/95 course i have booked for august and ive come across a question im a little unsure about......even when i have used the regs and GN3 to help. a little help would be greatly appreciated as there is no answer sheet for the...
stevo
Thread
circuit
disconnection
earth
impedance
revision
state
trouble
Hi, a bit of advice required. I need to install another d.b to a garage, the tails are to be split. The earthing system is TT, the cable is armoured, clipped to the side of the building & over to the garage on a small cantenary wire. As it is TT would the distribution cable need to have rcd...
found this today on a pre sort-out inspection:
all appears fine apart from the downstairs sockets not on the RCD side...split load board to the 16th ed
now lets pan down a bit:
yep...its TT...heres some more:
i wasn`t too impressed with the workmanship here either:
went into...
I want to remove the fused isolator that fed an old storage radiator, neutral & earth no problem, but the live comes from the timeswitch protected by a sealed cover.
Service fuse seals are often missing :D but not sure about timeswitch?
I thought of terminating in a small henley block?, but open...
Hi all,
Your help would be appreciated. We are mainly domestic sparx so I havn't much experience with cable sizing for motors.
On site, we need to supply a motor control panel which operates the sewage pump. There are in fact two pumps but I think they switch between periodically to prolong...
mark_
Thread
cable
cable size
control
disconnection
discrimination
motor
panel
phase
required
single
single phase
size
Hi guys,
Just doing an EIC for a recent dis board change, I also installed a 50a (type b 60898) shower circuit for an 11.5KW shower. I am looking through my regs trying to find whether it comes under the 5s disconnection time...? I know 0.4s is for circuits less than 32A and non-distribution...
Opinions needed...past the halfway mark in a major house refurb. (for info: am qualified electrician - although it's not the day job - Part P handled via Building Control). Top half of house is still a building site, lower half of house is sort of okay, but rough round the edges. Rang up EDF...
Hi guys had a conversation with the boss in the office after work today about a zs I got on a 32A c type rcbo bs 61009, the earthing system is TN-C-S, he said he wasn't worried I got a zs reading of 0.90 even though a type c 32A rcbo has a max zs of 0.72 his words were "it's just like a TT...
Do I need to notify the disconnection of a shower circuit?
I have disconnected and made safe at the consumer unit and confirmed at the business end that the circuit is de-energised.
If I do need to notify, on what basis am I doing so? Alteration in a special location?
Sage advice/experience...
Hi everyone,
On the drawing it says the system's TN-C-S with declared Ze = 0,008 Ω and prospective fault current declared as 50kA
When I calculate If = Uo / Zs = 230 / 0,716 = 321 A . With this value there's no way to match with 10A curve at fig. 3A6 (appendix 3)
But if I calculate the...
JuniorSparky
Thread
calculate
cpc
disconnectiondisconnection times
size
thermal
times
We have a a grain store refurb that needs completing , but in order to get a new panel board in on the 400a head we will need e-on to temporally disconnect the supply while the old one is removed and the new one is mounted and retailed .
Has anyone else done this before and if so what sort of...
HI.
I have recently installed some circuits at work and i am having problems proving that the fuses will disconnect before the cables used get to their max permitted temperature.
The two circuits are as follows:
1. 6mm L,N,E singles connected to a 32 amp HRC fuse...
Tn system disconnection time 0.4 s under 32a , 5s over 32a
So if a circuit isnt protected by rcd, how do you know if the circuit breaker is tripping less than the maximum disconnection times. Does it rely on low max zs values and ze
I understand that a disconnection relay must disconnect in the event of mains supply failure, however by what means does it achieve this?
If a sterling engine type generator is connected into a final circuit, what is the disconnection relay monitoring to register the mains failure? If anyone...
What is the maximum earth loop impedance to BS7671:2008 for a circuit protected by a 20A BS88 (gG) fuse giving a 5 second disconnection time is:
A: 7.42
B: 2.91
C: 1.84
D: 1.35
The green book says the ln for this type of fuse is 78A p299, that doesnt give you the right answer though.
:confused5:
On the 2391 training course for all of this week and something popped up that I would like to what other people made of it.
So we are talking disconnection times, and the question of RCD's pop up. More to the point, circuits not meeting the required disconnection times. I thought I would use...
sambotc
Thread
circuit
disconnectiondisconnection times
fault
installation
protection
rcd
times
Hi all, looking some advice on s type rcds. Basically can you use them on tt installations for earth fault protection on circuits that don't require additional protection? Know that on a tt installation disconnection times of either 0.2 sec or 1sec must be achieved depending on circuit, but with...
I always been told that an 30m/A RCD should trip within 200m/s (x1) and 40m/s (x5). But something iv never taken much notice of before is on test sheet the maximum disconnection time of a circuit less than 32A is 0.4. So....which is it? within 0.4 or within 200m/s????
hi guys,
what is the max allowable disconnection time times under fault conditions for kitchen lighting, bedroom socket outlets and also for a shower?
thanks in advnace i appreciate all your help
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