Hello,
Relating to a house/domestic installation, is there a maximum length for 25mm meter tails? I have got it into my head (old age creeping in!) that it is a metre - need confirmation/advice about this from any kind souls watching. Thank you, from member's first posting.:o
Hi all can anyone help me get my max D calculations down to under a 100a not sure if ive compltely got the wrong end of the stick with the maths any ideas would be greatley welcomed. Ive attached jpeg below, please double click on image to view.
Guys did a consumer unit change over the weekend and hit 2 snags
1. The suppliers cut out fuse has no markings on it ie no BS 88 60 amp instead the unit is black with no markings on it so how to I id it for the cert. The property is a 3 bedroom 1950s flat TNS supply.
2. Maximum demand I...
Hi,
A while ago I remember somebody mentioning a quick way of working out max demand with out doing it properly and it came out roughly the same as if you work it all out. It was something like add up add the rcb's and divide by 4 or something.
Anybody know what I am on about or was is this...
Hi Guys New guy here can someone advise me what is the maximum earth continuity reading allowable on a lighting circuit which is protected by a 5 amp fuse and has about 100 mts of 1.5mm T&E utilised
I'm doing 30mA & 100mA RCD resting on a TN-S system
TN-S earth fault loop impedance max is .8 ohms
TT earth fault loop impedance max is 200 ohms
Regs state approx 1500 ohms for RCD on TT system
What should the maximum Zs be on a TN-S system when testing an RCD?
Looking at job this week, involving fair bit of additional 3phase equipment...
Just wondering how to go about calculating maximum demand + diversity for this ?
Any Ideas please?
can someone please help me with this question
There is a 40A BS88 fuse, protecting a 10mm cable with a 4mm Earth, it is wired to Reference method C, supply is TNS and it is protected by a 30mA RCD. What is the maximum length the cable can be?
(thats all the info i have! I haven't been to...
can someone please help me with this question
There is a 40A BS88 fuse, protecting a 10mm cable with a 4mm Earth, it is wired to Reference method C, supply is TNS and it is protected by a 30mA RCD. What is the maximum length the cable can be?
(thats all the info i have! I haven't been to...
We are all familiar with the requirements for measuring Zs and verifying that it is within the limits for the particular type of protective device. I use a single guide of 1.2 ohms as the maximum though there are of course many variations.
What we (I) have not been noting is (R1+ Rn) and the...
for a TT system in domestic house with 0.2 disconnection time, with either mcbs or fuses. do i use the max Zs values in Tables 41.2- 41.4 which have 0.4 and 5 s disconnection times ? obviously depending on type of circuit.
Hi guys,
ready for it yet another blonde moment from me, trying to get my head round my training.
Regarding Maximum Demand load Amp/kA on the certificate
If you have an existing installation you can measure the maximum demand load by by switching almost everything on the circuits and...
hey guys i am studying for my C&G level 3 and i have my practical inspection and testing next week and i cant find anywhere thae values that are aceptable when you read continuity on a lighting circuit for instances and they havent told us at college
i presume it is somethning to do with the...
I did find the answer pretty much to this in an old thread & was answered by Chris...
But wonder if I could get a few more suggestions as to being correct.
Installed a Main Water Bond from a DB Board to the Main Incoming water supply which was (in my opinion) well over 25m away. We ran it along...
I can't find anything in the regs. On a ring it's fine to run a spur from the MCB (so 3x2.5mm). On a radial technically it doesn't matter where connections are made to the circuit as long as the cable at any given position can withstand the load. So how many connections from the MCB would be...
i have my 2392 practical coming up.i'm fairly confident of the testing to be done on the board. the problem i'm gonna have is the three certificates to fill in. schedule of tests i'm fine with. schedule and inspections i'm ok with. but the certificate itself i haven't even seen and we've been...
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