SWA cable

[msholmes1]

can anyone tell me where I can get a table of information on the equivalent CSA of SWA cables armour e.g is 16mm 3 core cables armour equivalent to 6mm yellow green earth wire I'm after a table that gives this info

 

[RF Lighting]

Everything you want is in our wiki


//wiki.diynot.com/electrics:earthing_supply_types_and_bonding:swa_earthing

 

[ColJack]

and what is an adiabic ( sp? ) equation?

 

[Stulz]

and what is an adiabic ( sp? ) equation?

An adiabatic equation is a term used that was adopted from thermodynamics and refers to any reaction or equation where there is no net loss or gain by one of the elements in that reaction/equation.

Many calculations in Airconditioning are adiabatic as the expansion or contraction of the gases involved does add or remove energy from the gases to facilitate a temperature change, it is achieved by either expansion or contraction of the respective gas. In the electrical field there are several equations that are adiabatic as there is no net gain or loss of energy. Hope this helps.

 

[ricicle]

The adiabatic equation assumes that all heat energy generated during a high current fault (short circuit) remains in the cable.
It can be used to find the time taken for a cable to reach its maximum safe temperature (without causing damage) so that it can be ascertained that the protective device will operate before this time.
It can also, on transposition, determine the size of conductor to be used for a given fault current.
Some assumptions have to be done as to know fault current you need impedances, but to know impedance you have to have conductor sizes so it can be reasonably involved!

 

[Spark123]

It is referring to S = Sqrt(I²t)/K , where S = minimum size of SWA conductor, I = fault current, t=fault duration and K is the K value for the steel armour. Like ricicle says, it can be pretty involved!!