more on assessment

[Mark2spark]

Hi guys,

some of you may have read my other thread about my elecsa assessment, I passed, sort of, had a non conformance due to main bonds on house being covered up/moved by kitchen fitters.

But I thought I'd comment on other aspects of the assessment, in case it helps others.

Much is made about '5 day wonders' becoming DI's and whatever, but I have to say I don't know how. I thought the questions asked were pretty tough, far beyond the knowledge range of someone who (supposedly) just a few days ago didn't know jot all about sparking.

I thought the questions were also phrased in a way to make you guess beyond what was being asked. The example is:

"What 4 factors can affect the current carrying capacity of a cable?"

So obviously I went for thermal insulation, grouping, length of run I said, no, he said, that's volt drop... (WTF?)(it either affects it or it doesn't?) ambient temparature... I couldn't think of a fourth (fifth actually) one... sunlight?

An awkward silence.

"At the start of the circuit..." he said

"A fuse or mcb?"

"yes, that's it..."

Smiles all round... err no, think I'll open my big mouth on that one... "that doesn't really affect the cable like the other factors do though does it? It limits the current sure enough, but I think that's mis leading..."

Another awkward silence.

Think I've got a lot to learn...

 

[NWDS]

Afternoon Iam with Elecsa as well, I thought it was just me that felt like that, the guy who did my assessment was very good with me he explained points I was stuck on and watched for my reaction, before he finished he explained that we all have to start some were and some I got right and the ones I got wrong we talked about untill I had got it.

NWDS

 

[Gforce]

But at the start of the circuit being mcb or fuse is 1 factor-what other 3 are there at start of circuit affecting carrying capacity?

I see what he means though the volt drop stuff isnt directly responsible for what the cable can actually carry-but what is acceptable for volt drop.

The size of the cable would surely be one-as the larger the cable size the greater the amps relative to volts which equates to current.

 

[Mark2spark]

But I might as well have said that a nail right through the middle of a cable will affect the ccc?

It was just worded strangely IMO for an obvious question.

 

[Mark2spark]

The size of the cable would surely be one-as the larger the cable size the greater the amps relative to volts which equates to current.

I said that one too... but he said no, doesn't matter how big the cable is if it's fused at 1 amp that's it.

Strange way of going about things... thermal wouldn't affect it either if it was fused at 1 amp? :_|

 

[Gforce]

Yeah I suppose-but what would the other 3 things be lol

 

[Mark2spark]

Yeah I suppose-but what would the other 3 things be lol

Sorry, didn't realise that I wasn't clear, thermal insulation is one, grouping is two, and ... ummm ... errr... Blushing ?:| Ahh... Ambient temparature!

Page 123 OSG

 

[SPECIAL LOCATION]

"What 4 factors can affect the current carrying capacity of a cable?""At the start of the circuit..." he said

"A fuse or mcb?"

"yes, that's it..."

Smiles all round... err no, think I'll open my big mouth on that one... "that doesn't really affect the cable like the other factors do though does it? It limits the current sure enough, but I think that's mis leading..."

Sorry, didn't realise that I wasn't clear, thermal insulation is one, grouping is two, and ... ummm ... errr... Blushing ?:| Ahh... Ambient temparature!Page 123 OSG

Hi Mark2Spark,

once again congrats on your pass m8Guiness Drink

I think what the assessor was trying to do here was to find out if you knew what "Correction Factors" were,

without actually using the word correction factor!

For the benefit of any others reading.......

you do have the Cc factor for semi enclosed wired fuses...

e.g.

With the type of fuse you have the 0.725 factor which you don't get with an MCB! e.g. 20A MCB is different to 20A rewirable fuse.

(& different Zs's)

We are talking here of when you design a new circuit...

the tabulated cable capacity must be >= design current/(Ca,Cg,Ci,Cc)

Ca Amb temp

Cg grouping

Ci Thermal

Cc Protective device.

So its not the actual fuse rating... more the fuse type!

The assessors problem was how to ask if you understand this lot without using the give-away word correction factor IMHO. :|

Bit like some of the C&G exam questions..... :_|

worded to try and make you think!

 

[Gforce]

Thanks for that guys-ill add that to my homework to studyApplaud Smiley

 

[Mark2spark]

The more I think about it, I think Special Location nails it... he couldn't really ask the question simply without giving the game away!