Earthing

Drive new copper grounding stakes into the ground and run copper wire to the grounding terminal on the PLC. That's basicaly it. Now you may need to give consideration to how you will route the new grounding wire and have the new grounding stakes certified but any electrican can figure this out, you just need to spend the money.

Sir,

Earthing of Medium Voltage Station, Lightning, Low Voltage station, Instrumentation/Automation/Electronic, must be all separated. Load cell and PLC can be one stake/rod, all LV system can be joined to one system of earthing.

Have to contraint in the definition of system because each system level have their own specific hazard different from others.

MV station commonly use mesh grounding system with total value around 1ohm(some say 3ohm), while for electronics should have 0.xxohm.

Lightning, you must have the external and internal surge arrester.

You have to buil a lightening system that is seperated from your earthing system.

Because of they are two different systems with different purposes.

NAM70,

you were the first person with a brain in this Blog! Well done, the rest missed it completely....

I wonder if your tip was fully understood or not!!!! We will see......

Have a great day!!

Dear Andy,

Thanks for your concern!!!.

Have a nice day!

All the others have gone REAL quiet, I think that "the penny has dropped" as we say in the UK!!! Thanks to you!

Have a great day.

It is not a good practice to install separate earthing for PLC's. I recommend you to follow the IEEE Std. 1050-1996 "IEEE Guide for Instrumentation and Control Equipment Grounding in Generating Stations (ANSI)".

Hi.all

Whats the earth rod omh rating requirement for Lightning Rod arrestor ? How about for equipment(chiller, compressor, etc) eathing rod rating? Any guideline? Thanks.

Loads of them. British Standard 7671 is among them, for example. Simply select the electrical code applicable to the country of installation.

If in doubt, consult a qualified local Electrician.

to protect from lightening you have to use lightening protection system.Ingesco from spain is one company.you can follow lightening protection as per british standards for which furse is the manufacturer.to protect electrical system use surge suppressor of emerson in the main LV panel.the rating has to be designed.

you should construct separate earth pit and earthing for your PLC and should be checked periodically to avoid such failures. The general earthing may not be always free of charge as there may be some neutral shift voltage due to unbalanced load and will discharge to earth if it is neutral earth system .Surge voltage may cause voltage in earthing system and will cause damage to PLC if connected with general earthing system. The normal procedure is to provide separate earthing for LP system, electrical earthing and static earthing .All computer controlled machines should be provided with independent earthing.