Originally Posted By: roconnor This post was automatically imported from our archived forum.
I was asked a question that I thought I would post here for discussion.
On an older main panel, what would be the acceptable installations of lightening/surge protection? Would it be acceptable with lightening/surge protection double tapped off the main lugs of a service panel, or what issues do you see? Was it always done that way, so this is only a "concern".
I am not used to seeing that on a residential panel, and for commercial installations I am used to seeing that connected off one of the breakers.
The double lug would not cause what I would consider the major hazard of that, which is possible overloading of the feeders. The only real issue I see is the double lug on the panel mains causing wire-to-wire contact and possible deterioration. Any thoughts?
-- Robert O'Connor, PE
Eagle Engineering ?
Eagle Eye Inspections ?
NACHI Education Committee
I am absolutely amazed sometimes by how much thought goes into doing things wrong
Originally Posted By: dbush This post was automatically imported from our archived forum.
Robert, if we are talking about the same type, there is a very nice surge protector that fits under the meter through the lugs, it is a plug in type that the meter plugs into. They can be leased from the electric company and provide whole house surge protection.
Originally Posted By: jfarsetta This post was automatically imported from our archived forum.
A double tap is a double tap. The correct way to provide protection is broken into three variables: protect the contents of the panel, protect a branch circuit, or protect a device.
Protecting a local device(s) can be accomplished vis portable, plug in surge protector or UPS.
Protecting a branch circuit is an in-and-out thing, where the protector sits on the out side of the breaker, and branch wiring can connect to it.
Panel protection should take place before the branch circuits, and after the main disconnect.
Of course, if the system is not properly grounded, or if ground loops exist, it doesnt matter what type of spike/surge/sag/lightening protection you have. Grounding is the key element.
-- Joe Farsetta
Illigitimi Non Carborundum
"Dont let the bastards grind you down..."
Originally Posted By: roconnor This post was automatically imported from our archived forum.
Thanks Joe. I agree about the double lug being a concern, but wasn’t sure about common ways of protecting a residential service at the panel.
On smaller commercial services with sensitive equipment I am used to seeing a dedicated 2P/3P breaker for connecting service surge protection, which is located in a separate box below or next to the panel. There are most likely lots of ways to do it, but that surge protector at the meter Dave described sounds like a good option too if available.
It was actually described as a small unit inside the service panel, with the wires double lugged off the panel main. Just seemed unusual to me, besides the wire-to-wire contact issue on the tap.
-- Robert O'Connor, PE
Eagle Engineering ?
Eagle Eye Inspections ?
NACHI Education Committee
I am absolutely amazed sometimes by how much thought goes into doing things wrong
Originally Posted By: jfarsetta This post was automatically imported from our archived forum.
If you’d like to know more regarding this type of protection, for residential and commercial, visit Best Power Technology.
I had one of their FerrUPS units sustain a direct lightening hit, and still protect the data and communications equipment behind it. The control panel looked like toast, the batteries were burned and cracked, but the ferroresonant isolating transformer within the unit took the hit, protected the systems, and continued to run. That $6000 stystem protected $800k worth of equipment...
-- Joe Farsetta
Illigitimi Non Carborundum
"Dont let the bastards grind you down..."
Lets go conservative and say 10 million volts and lets say your surge suppressor is 99% effective, that still lets through 100,000 volts. 
If your equipment takes a direct hit there is nothing that can be done it will be destroyed.
All you can hope for is a little more protection, against a nearby hit.
Of course you could build a Faraday cage over your house.
Yeah that's a guy in there, I have seen this in person it is pretty cool. 
Originally Posted By: Bob Badger This post was automatically imported from our archived forum.
roconnor wrote:
Would it be acceptable with lightening/surge protection double tapped off the main lugs of a service panel, or what issues do you see?
Along with the double tapping if you mean it was tapped on the supply side of the service disconnect you have a violation of 230.82 Equipment Connected to the Supply Side of Service Disconnect.
There is also the issue of overcurrent protection of the conductors and the device itself.
The "tap" rules do not apply unless there was a overcurrent protective device in line with the surge suppressor.
A better method for a home service is a two pole breaker sized to the conductors on the surge suppressor.
There are a lot of requirements when installing these, few bends in the conductor and no sharp bends.
Originally Posted By: roconnor This post was automatically imported from our archived forum.
Bob … That sounds pretty cool. Where do I sign up to almost get zapped …
I agree with Mike and Bob that any protection at a residential panel is really only for "surge protection", and wouldn't even come close to true "lightening protection". It's really intended to protect from voltage surges on the line/utility side, either caused by lightening strikes there or the more common voltage spikes.
I have worked on small commercial jobs where we specified special provisions like "air terminals" on the roof, large diameter wires for a "ground path", and elaborate "ground loops" and "XIT ground rods" below grade ... even that wasn't called lightening protection ...
And talking about lightening, how the heck did Ben Franklin not get zapped with the "experiments" he did ...
-- Robert O'Connor, PE
Eagle Engineering ?
Eagle Eye Inspections ?
NACHI Education Committee
I am absolutely amazed sometimes by how much thought goes into doing things wrong
Originally Posted By: jedwards This post was automatically imported from our archived forum.
roconnor wrote:
And talking about lightening, how the heck did Ben Franklin not get zapped with the "experiments" he did ... 
Even I know the answer to this one. The honorable Mr. Franklin prepared himself mentally and physically for all of his "revolutionary" endeavors. In his own words...
"Beer is proof that God loves us, and wants us to be happy."
I have a T-shirt with this quote. God bless the Founding Fathers.
Originally Posted By: rpasquier This post was automatically imported from our archived forum.
jedwards wrote:
roconnor wrote:
And talking about lightening, how the heck did Ben Franklin not get zapped with the "experiments" he did ... 
Even I know the answer to this one. The honorable Mr. Franklin prepared himself mentally and physically for all of his "revolutionary" endeavors. In his own words...
"Beer is proof that God loves us, and wants us to be happy."
I have a T-shirt with this quote. God bless the Founding Fathers.
I gave that T-shirt to my father 2 years ago, and he has just about worn it out he wears it so much.
Gotta love it!!
My favorite T-shirt says this, I don't have an attitude problem, You have a perception problem.
Sorry, went way off the subject there, what were we talking about?
I do not recall them saying anything about Ben's love of beer, but it would take a lot of it to get me flying a kite in a thunderstorm. 
