International Lightning Protection Standard

[bphgravity]

I have been reviewing the new TC-81 (IEC 62305 1-5) international standard for lightning protection systems. It definitely appears to be a much more sound and technically accurate standard for lightning protection.

Unlike the NFPA 780 or LPI 175, the TC-81 breaks down LPS into categories based on its purpose, risk analysis, and type.

For example, protection from life and property damages, protection of electrical and electronic equipment, and protection of utility services entering the structure are discussed separately instead of one general protection method. These are again broken down into risk management methods which identify the total level of risk on life and property. And unlike the NFPA 780 which is only a minimum standard, this standard provides 4 types of protection methods based on a set of minimum and maximum lightning current parameters.

Another interesting idea is the installation of horizontal air terminals verses the conventional vertical rod. The standard also calls for short length ground rods (3-4 feet) driven at an inclined angle of 30? instead of the typical deep ground electrodes (8 foot) driven vertically.

The standard is fairly expensive and broken into 5 books each costing around $200. However the standard is being coordinated with UL and other NRTL for compliance with the UL96A.

 

[Pierre C Belarge]

Bryan
Have you found a way to get more than 24 hours out of the day???

Either your time management is very good, your reading/comprehension skills are excellent or you found a way to get more hours out of the day. :wink:

 

[ramsy]

Re: International Lightning Protection Standard

However the standard is being coordinated with UL and other NRTL for compliance with the UL96A.

Brian, are updates to standards like this always limited to the next NEC code cycle, if referenced directly, or does the NEC have a clause that assumes the current prevailing deffinitions?

For example, the NEC is riddled with the terms "Lightning Protection" and "Air Terminals", but the references may be dated: (ie) NFPA 77, 780, API RP, etc..

2002 NEC 500.4 FPN No. 3: For further information on protection against static electricity and lightning hazards in hazardous (classified) locations, see NFPA 77-2000, Recommended Practice on Static Electricity; NFPA 780-1997, Standard for the Installation of Lightning Protection Systems; and API RP 2003-1998, Protection Against Ignitions Arising Out of Static Lightning and Stray Currents.

 

[bphgravity]

The NEC updates to the most current edition of the referenced standard during its code cycle. All referenced standards in the NEC are in the form of a FPN or bracketed immediately following the text extracted from the referenced standard. I would assume that when a referenced standard is updated before the next edition, the most current edition would apply. But I am not sure on that. In general, this information is not enforceable anyway. The individual standard or reference edition must be specifically adopted by your jurisdiction or state.

As long as the NEC publishes a lightning standard, I seriously doubt the TC 81 standard will be referenced in the NEC. The NFPA appears to be sensitive about the IEC as indicated by 90.1(D) and its FPN.

 

[ramsy]

In general, this information is not enforceable anyway. The individual standard or reference edition must be specifically adopted by your jurisdiction or state.

Thanks for clarifying this Brian. The NEC demands I see are 6 foot proximity between raceway/cable and lightning-conductors, bonding lightning systems to the grounding elctrode system, installing protective enclosures for lightning protective devices, and excluding lightning systems from elevator shafts.

Except for irrigation machines, class 2 or 3 primary protectors (enclosures), and buildings without grounding, I see no other NEC demands to install lightning systems, or bond roof top equip. to such systems, without local demands.

 

[don_resqcapt19]

Brayn,
Have you looked at any of the information related to the NFPA's Standards Council decision to withdraw NFPA 780. I think this happened in 2000, the decision was reversed. It all was a result of an attempt to get "early streamer" emmissions type of lightning protection into 780. A task force was formed to study the issue and found that there was no scientific evidence that the early streamer system worked, and then they looked at the air terminal system and found the same. This is from memory and some of my details may be wrong.
Don

 

[bphgravity]

From what I understand, the players backing Early Streamer Emission, Charge Transfer Systems, and Dissipation Array Systems argued and proposed that traditional LPS's were ineffective while their systems are effective. The Standards Council decided to suspend issuance of the NFPA 780 until it could be investigated by commissioning the government and a group of scientists to issue separate reports on their findings.

It certainly appears both completely discredited the above systems showing they have absolutely no merit. It also appears they both reserved comment on traditional systems but claimed they were more likely to be effective so they should continue to investigate them. The Standards Council then decided to continue with the NFPA 780 program basically as is.

The next edition is scheduled for 2007. It is in the comment stage right now and had a fairly healthy proposal period. It does appear many of the proposals and comments are excerpts of the TC -81. This is probably a good thing.