Earthing Requirements

[rajeshbahl]

Generally it is mentioned in the computer/printer manuals that the equipment should be connected to "Properly grounded" outlet. If referred to the word"properly", there are different versions available.

Where can I find the details of electrical requirements (particularly earthing) for installation of computer equipment ? What can happen if this "proper" earthing is not there? We have seen PCs and peripherals working okay at sites where there is NO earthing at all.Why the equipment keeps working in such conditions if these are mandatory to the installation and operation of PCs?
Are there any additional electrical requirements for serial communications/Networks?

Can anybody suggest/guide some details/insight in to this?Is there any website that describes these standards in details ?

Thanks In Advance
Rajesh K. Bahl

 

[denodave]

Bottom line is that earthing provides a way for AC power to leave the device rather than remain trapped. Same goes for static charges that build up inside machines or are introduced from outside.

Earthing is not absolutely necessary! It is the primary and best way to prevent an electrical mishap should a charge build up for accidental or failure reasons.

I will try to get back with some references later in the day if possible. Try searching some major electrical manufacturers' websites, like Siemens or Hubbell-USA. Email me! denodave@yahoo.com
Real men pray...especially techies!

 

[edfair]

Try a search for "national electrical code". Specifications are for the ground to be tied to either a buried conducting water pipe or other conductor of a specified length.
Grounding a case is a safety procedure to keep a potential fatal wiring error from placing a voltage potential on the case that could flow through a person to another grounded case or conductor leading to ground.
Electrical equipment is designed to work with the potentials provided between the hot and neutral wires in the system. The ground is a safety feature.
For serial communications the signals are generated with respect to a common voltage which is not at ground level since they may be involved with machines at different potentials because of where they are on the electrical grid.
For networks, coax is normally grounded on one end only, cat5 uses the potentials between the send and receive wire sets and grounding is not used.
Ed Fair
unixstuff@juno.com
Any advice I give is my best judgement based on my interpretation of the facts you supply. Help increase my knowledge by providing some feedback, good or bad, on any advice I have given.

 

[ceh4702]

Usually grounded outlets just have a connection to a cold water pipe that goes into the ground; Metallic, preferrably copper. If you have an above ground house you can get a grounding rod and put it in the ground under your house and run the ground wire to an outlet. If you only have 2 wire plugs you can buy a 3 wire outlet and ground it yourself. More modern houses are suppose to have 3 prong outlets. It is possible to run 3 prong electrical wire to a small utility box back to the main panel and provide power from that. I have had many computers plugged into 2 prong plugs through a surge protector without any problems.

You are more likely to get your computer equipment zapped from a lightning strike coming through the phone lines or a cable modem!!!! If you do not like my post feel free to point out your opinion or my errors.

 

[rajeshbahl]

Thanks to all of you for responding to my query. There is still one confusion: Some techies say that if earthing is not there or improper, the component (motherboard/hard disk/RAM) burning rate will increase.I do not know how far this is true ?

Is there any connection between component burning and earthing? I have also seen some machines fully burnt and as per engineers happened because of improper earthing.

Also in case of serial communication, is the number 7 signal on the serial connector is to be connected to electrical earth ? And in this case the potential difference between these two "earths" can always create problems?


Regards
Rajesh K. Bahl

 

[edfair]

Burning rate will not increase if no earth is present.

There are problems that can occur if things are hooked up wrong. But in general I would be suspicious of those claims unless the engineer could explain in a way you understand.

Common (pin 7 on D25) is not to be at earth. It can, but doesn't always , create problems. Ed Fair
unixstuff@juno.com
Any advice I give is my best judgement based on my interpretation of the facts you supply. Help increase my knowledge by providing some feedback, good or bad, on any advice I have given.