sundance-communications.com/forum Forums General General Telephone & Systems Information Grounding of KSU's directly to the cabinet

Westom, please complete your profile with your occupation so that we can know who we are talking to.

-Hal

Excuse the advertising aspect of my post, it is designed to be enlightening not commercial.

We had issues with the old Prostar 816 and one day I was at the CES show in Vegas and EFI (Utah company) had a 2500 volt, 2500 watt circut blowing up other people's surge protectors then substituting theirs, and the light bulb stayed on.

We made installing one of the EFI surge protectors a mandatory part of every system sale. We stopped having problems with dead 816s. We used them on EVERY system.

One day a recent Toshiba customer called up to say his system was dead. Balderdash, Toshibas don't die. All the display screens were dead, we unplugged the power cord from the EFI surge protector that had NO green light, put it in the wall and the Toshiba worked fine.

The surge protector was a mass of burned parts inside, we received a warranty replacement. You can say all you want about grounding, power spikes kill systems and they are so transient that you can't recognize them.

Sorry if anyone is upset that I recommend a REALLY GOOD company, but we made money selling EFI surge protectors, our dead power supply problems went to zero and the trouble you go through with warranty repairs stops with an EFI "One millionth of a second response" from their units.

No, I don't get paid for this advice, not even a free surge protector, they just saved our asses a lot of trouble and I felt the need to pass this on. Bracha

I don't take it as advertising. As techs, we need to know what works and what doesn't.

Hey Westom,

I happen to live in Western PA and Westinghouse spent multiple millions of dollars building a man made lightning lab in Hunker, PA. Those statements are NOT wild speculation. The examples you site as proof electronics can survive direct lightning strikes are Faraday cage protected. If you want to know about telephone companies being wiped off the air due to direct lightning strikes, just do a simple Google search. There are MANY incidents.

The information given is well documented and real world proven.

Rcaman

Telesystems: Grounding (as some have described) is essential and defines hardware protection. But what others have posted does not completely describe what you must understand to have a useful answer. Some cite another's facility as if it proves they also know what those others know.

One cites a Faraday Cage while completely ignoring what should have been obvious. Described by proper earthing and current flows were the basic concepts of a Faraday Cage. If he understood what I had posted, then he understood I was discussing what makes a Faraday Cage effective. He did not understand I had posted 'Faraday Cage' concepts.

Appreciate these concepts are mostly unknown to electricians (technicians). Electricians are taught what must connect to what mostly for human safety. Concepts relevant to your questions include impedance. Electricians are not taught about impedance. Or why metallic conduit, sharp wire bends, and longer wire increase impedance. Even wire thickness is mostly irrelevant to impedance.

Fundamental to protecting a KSU is to identify how a surge connects to earth. Earth the surge; not its victim (KSU). Chassis bond (safety ground to meet UL or NEC requirements) is irrelevant. Hardware protection is about a current that does not enter a building (to duplicate what a Faraday Cage does). When a surge does cause damage, then professionals eliminate the human mistake that made damage possible. hbiss introduced some of this. Others do not even know that proper earthing routinely makes direct lightning strikes irrelevant. One even invented a mythical number (billions of volts). Remedial efforts focus on correcting the only and most important component that must exist in every protection system - single point earth ground.

Yes, ground redundancy can be part of a solution. As long as it does not violate what is important - single point ground. Protection is a building wide solution. Protectors adjacent to a KSU can even make damage easier for many reasons. Including no low impedance connection to earth.

Significant useful information can be provided if asked for. Some of that was summarized in what was only an executive summary. No reason to provide relevant details for others who only want to deny, attack, contradict 100 years of well proven experience and science, and who do not provide specific and useful recommendations. Protection is always defined by the most important component in every protection system - single point earth ground.

Westom, You should of named yourself, "Mr. Ground"

This is still pinned in Outside wire construction and after a quick read I'd still say it's still pretty spot on.

Everyone's opinion has value, but proper grounding and bonding can save you and the customer some bucks. We've all learn a few tricks and experience is worth it's weight in gold.

Ok guy's...Been watching this thread and everyone all has some great ideas as to what happens with power/ground ! But now were starting to question each others knowledge and turn it into a wizzing match...Let's try to keep it on the topic and not on each other if we can..That's what the forum is for to learn..heck I can argue with my wife..:-)

Thanks

...bob...

Why do some manufacturers not put grounding lugs on their KSU. Like x16. Is it because they do not need them?

That's probably fodder for another topic so we don't hijack this one.