Cert queries

[Sjn electrical]

Hi all, Have a few queries about filling out test sheets.
I will be using these for my assessment on Tuesday so dont want to get them wrong.

1, Max demand load-is this what i caculate to be max loading of all circuits?

2, Uo- looked it up in the regs but confused!!!

3, Is a BS 88 fuse class II?

4, Will the main fuse have its short circuit capacity written on it as i couldnt see it.

5, Does anyone know where i can find a risk assessments for electricians? looked all over the HSE website but no joy.


Any help would be greatly appreciated.

Steven

 

[Guest123]

Hi all, Have a few queries about filling out test sheets.
I will be using these for my assessment on Tuesday so dont want to get them wrong.

1, Max demand load-is this what i caculate to be max loading of all circuits? Calculate maximum demand for the install using diversity.

2, Uo- looked it up in the regs but confused!!! Uo is nominal voltage line to earth.

3, Is a BS 88 fuse class II? Depends what is written on it

4, Will the main fuse have its short circuit capacity written on it as i couldnt see it. Not always

5, Does anyone know where i can find a risk assessments for electricians? looked all over the HSE website but no joy. Try a search of the forums.


Any help would be greatly appreciated.

Steven

Try searching the forums, there'll be some downloads with info on risk assessments & fuse info to help you.

 

[Sjn electrical]

Hi Lenny, Thanks for the reply.
Do you no where i can find the diversity caculation?
Regards Steven

 

[rocker]

In your on site guide or the BRB

 

[Electricalserv]

Nominal voltage (Uo) for the UK IS 230V but it can vary between 216.2v and 253.0.

I measured one the other day which was 242v. It was the same for 3 houses in that area.

 

[Geoffsd]

The Nominal voltage doesn't change.

 

[Electricalserv]

The Nominal voltage doesn't change.

Who said it changes? I think you will find that voltages are different in different areas if you have ever taken time to measure one....As I've stated they can vary between 216.2v and 253v.

I measured ones at 242v this week and last....not exactly the UK standard 230v mid range

 

[Geoffsd]

Yes, but the NOMINAL voltage is 230.

 

[Electricalserv]

The guy asked what Uo was....He was told its the nominal voltage. Nobody explained it was 230v or what it represents. The nominal voltage is the midpoint of voltages on average across the UK. So I explained what it is....

Not once did anyone mention it changes....

 

[Guest123]

Nobody explained it was 230v or what it represents.

TBH I didn't think I'd have to......!!

 

[Electricalserv]

Lenny I was under the inmpression that if he had already looked the definition up in the regs and he was still confused then maybe it needed a little more explaination

 

[Geoffsd]

Nominal voltage (Uo) for the UK IS 230V but it can vary between 216.2v and 253.0..

......

 

[Electricalserv]

......

Point is....''nominal voltage in the UK IS 230V"...maybe I should have put but the voltage varies across the country. You know what I meant!!!! otherwise I wouldn't have put ''nominal voltage in the UK IS 230V"

Not exactly rocket science knowing that the nominal is 230v...I explained to lad what it is and what it represents...More than you have offered.

 

[Goody]

Hi Lenny, Thanks for the reply.
Do you no where i can find the diversity caculation?
Regards Steven

Plz check this out -> http://www.electriciansforums.net/electrical-forum-general-electrical-forum/33623-diversity.html

 

[ezzzekiel]

counting up breakers then taking the largest and and adding 40% of the remainder is a quick rule of thumb method and acceptable for most domestic installs.
when a more accurate figure is required then using the formula from osg is to be used.

Uo is taken as 230v

dont think ive ever seen (or noticed) the short capacity written on a fuse or carrier but the values are in the book and you will only ever encounter a few types so once noted easily remembered.