Adiabatic Equation

[Rauer]

Just reading though "electricians guide to the building regs" that's riveting!!

 

[Amp David]

Sorry ,I'm brushing up for my assessment!

Part P assessment, I wouldn't bother brushing up on calculation method, theres not a cat in hells chance they'll ask for an example.

 

[Rauer]

When they talk about wanting to see design , what do they mean by this?

 

[ipf]

When they talk about wanting to see de sign , what do they mean by this?

The logo on your van!

 

[MarkieSparkie]

When they talk about wanting to see design , what do they mean by this?

The colour and denomination of the wads of cash you're paying them!imp:

 

[Geoffsd]

As a point of interest - working the adiabatic equation backwards -

taking t as 0.1s and k as 115 as most modern domestic cases will be

a 10mm² earthing conductor is good for a Ze down to 0.06Ω and

a 16mm² is only good down to 0.04Ω .

It would seem that the 16mm² is very rarely required, if at all.

 

[Amp David]

For the majority of my MEC I use 143 as the value for k as table

 

[Geoffsd]

That would make the required conductor even smaller.

 

[telectrix]

me too.

 

[Amp David]

That would make the required conductor even smaller.

Exactamondo:ihih:

 

[telectrix]

another few minutes, we can prove that a bit of wet string will do. :sunny:

 

[Amp David]

It usually will, won't it?

 

[telectrix]

judging by some of the Ra values i've seen lately, more than adequate.

 

[IzzyS]

I use 16mm earth and 25mm tails. The local DNO won't connect the supply if I don't - it's not only about BS7671...

 

[Rauer]

The DNO are only responsible to the meter, anything from the outgoing side is our responsibility ........ But they seal it and we are not allowed to cut them to inspect the connections on our side...... Hmm, so tell them to leave you an isolator to connect to