Earth Strip Size for Lift

If you want to double, the thickness should be the same 6mm....

Yes, there is a problem. Your total cross-sectional area is only half the apparent standard.

Yes, you're right.

Two thinner levers may not be enough.

I'll make it unanimous.

Yes, there will be a problem, sometime in the future when you least expect and can least tolerate it.

Like when you are really busy and need it.

Check your cross sectional areas! Something does not add up!

The pronoun <...We...> is a cop-out for individuals unwilling or unable to take responsibility. Now, to the matter in hand:

• Indian Standard 3053
• British Standard 7671
• Etc.

Every country has an applicable electrical code, which Electricians are employed to follow.

• Please explain why the applicable national electrical code is to be disregarded in this particular case?
• Please explain why the installation is to be carried out by individuals apparently so unfamiliar with the applicable national electrical code?
• Please explain why there is a need to post questions like those in the original post in an anonymous international Engineering forum?

There are times I'd like to be a fly on the wall so I could hear you explain to your boss why his earth ground system is costing 3 times more than he budget for? And why the code inspector is making you rip out the substandard work?

Only a bean counter would spend a dollar to save a dime ( US currency)

You'll have to buy more copper tape'

I will say 50x6 seems overkill unless this is part of a lightening system

'But I couldn't understand any of the subject ideas when I am studying'. From your blurb.

25x3x2 Earth strap will work better than a wet string or a dry branch.

To save on copper costs, just twist some fence wire together or better, just use the re-bar in the concrete or a few re-bars tied together with wire. For a well done job with good aesthetics, lug the ends and 'hey presto'. But it will not be as flexible as wet string or as insulating as a dry branch.

Apart from 50 x 6mm, which seems to me to be a colossal size for 24kw (I would check if this was correct) you need to get your areas the same. That means 4 strips of 25 x 3.

Reply to op... the saying goes something like....

Rules (standards) are made for the guidance of wise men, and to be obeyed by fools.

If in doubt follow to the standard and cover your ass! Or, do it your way, and pray forever?

jt.

A guy in the office says... mines 12 inches long... but I don't use it as a rule.

Simple math,really: 50 X 6=300.

25X3=75 X 2=150.

So you will need 4 runs to get equivalent.

Also,there will always be resistance and heat where two or more conductors are joined,presumable at both ends.

Even if CAD welding,the joint will always be hotter than the main conductors to some degree.

Then you have to consider the long term reliability of the parallel connections,due to corrosion,vibration,etc.and the warping and possible separation if required to carry a short circuit load;They could actually try to spread out like a bow string in the center due to magnetic effects of very high current.

The locale may also dictate the length and size and number of the conductors due to soil conductivity,moisture level,etc.

A conductivity enhancing chemical may also be required if the soil is a poor conductor.

Many variables went into specifying the dimensions of the ground strip.

Do not try to be an Ad Hoc engineer.

I hope the term"we" includes a "real" electrical engineer,so go ask him for advice.

If you cannot find the time and money to do it right the first time,where will you find the time and money to do it over?

"Penny wise,Pound foolish."

You're working with 24 kilowatts, that's a lot of power.

The standard for your country says to use a copper strip 55mm x 6mm.

You are using TWO strips that are HALF the width, and HALF the thickness. Each strip has a quarter the capacity of the standard, so together they provide half.

Even if you put in four strips, to meet the current capacity of the standard, the load across them may be imbalanced, due to flaws in the soldering, variances in soil condition, impurities in the copper, phase of the moon, etc. But somewhere, sometime one of those four strips will end up with more that the '1/4 of the total rated current' that you've designed it to take. That will cause it to overheat and stretch (making a 'thin spot' in the ribbon that will produce more heat, even when the loads are balanced again) or even 'blow' like a fuse. Once the ribbon blows, the other three will have to take the current it was carrying, overloading them, abd causing THEM to blow in a 'cascade failure.'

So you have two options:

1. Admit your screw up, pull those substandard ribbons out, and install the ribbons THE CODE told you to use in the first place.
2. Don't change anything, and hope that whoever gets KILLED when this fails (and it WILL fail) believes in reincarnation, had has led a good life up until then.

Why do we even HAVE building codes and standards if people don't follow them?

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