Lightning arrestor question

[blazenut]

I was at a house today that had a lightning arrestor on the panel (it said either lighting or lightning arrestor...it was all scratched up). This is the first on of these that i have seen in a panel. The one wire was loose (see picture). How do these work? And, is this how they are supposed to be installed (directly to the main feed)?

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[Mark P]

Well smarter people then me will come along with a response, but until that happens: here are my two cents:

I don't know how they work, but they are typically attached to the main lug, but from what I understand they can be attached anywhere in the main panel. The fact that one of the wires is disconnected is not correct and I would certainly call for an electrician to install it correctly or remove it completly.

[Bill Kibbel]

The main breaker terminals aren't likely labeled for more than one wire each.

Read the lightening arrestor/surge suppressor manufacturers' instructions. Every one I've seen requires the wires to be connected to an additional 2-pole breaker.

Most lightening arrestors/surge suppressors are capacitors that absorb and hold the surge of electricity. Then, they gradually return it to the circuit.

[Jim Katen]

I was at a house today that had a lightning arrestor on the panel (it said either lighting or lightning arrestor...it was all scratched up). This is the first on of these that i have seen in a panel. The one wire was loose (see picture). How do these work? And, is this how they are suppost to be installed (directly to the main feed)?

The installation is wrong for the following reasons:

The main lugs aren't listed to hold the smaller conductors.

The main lugs aren't listed to hold two sets of conductors.

The main lugs aren't listed to hold both copper and aluminum conductors together.

Of course, one of the conductors has come loose.

The arrestor leads are supposed to be as short a possible and terminate on their very own breakers, one on each pole.

I've never seen or heard of it done correctly. *Everyone* pretty much double taps them onto either the main lugs or onto the lugs of a branch circuit breaker.

- Jim Katen, Oregon

[Bain]

I'm tripping on a little deja vu, here. Does that mean I'm becoming a TIJ old-fart?

[Jim Katen]

I'm tripping on a little deja vu, here. Does that mean I'm becoming a TIJ old-fart?

Must be. Of course, we've only answered this particular question about 40 times.

What do you all think about a FAQ section in the electrical forum?

- Jim Katen, Oregon

[esch]

Should there be anti-oxidant paste on the aluminum wire connections?

Matt

Hah, Just did a search on TIJ and found some knowledgable info on the paste, "my bad".

I guess the answer is, Should be, but is not required.

[Jim Katen]

Should there be anti-oxidant paste on the aluminum wire connections?

Good idea, but not required by any rule that I'm aware of. It's certainly not an NEC rule.

I've heard people argue that the wire manufacturers require it (or perhaps suggest it), but I've never actually seen such a requirement. Has anyone else?

- Jim Katen, Oregon

[Bain]

Should there be anti-oxidant paste on the aluminum wire connections?

Good idea, but not required by any rule that I'm aware of. It's certainly not an NEC rule.

I've heard people argue that the wire manufacturers require it (or perhaps suggest it), but I've never actually seen such a requirement. Has anyone else?

- Jim Katen, Oregon

Hah! Deja vu, again. I was once taught in a CE class that paste was required by the NEC. I repeated that misinformation here, once, and Uncle Jim put his foot right up my ass.

[Robert Jones]

I, personally, would appreciate a FAQ section of the most common questions in this forum.

[blazenut]

Me too, that way i wouldnt have to "bother" some of the guys in here.

[Billy_Bob]

Basically think of a mom yelling "That's enough!" to the kids. No more will be allowed...

Newer surge protectors use an electronic component called a "metal oxide varistor".

Others might use electronic components called "zener diodes".

In either case, these components work like electric switches, but they only turn on at a certain voltage. And this would depend on the specific rating of the component.

One might "turn on" at 330 volts. So a surge of electricity comes through and this raises the voltage from the normal 120 volts to above 330 volts.

At the 330 volt level, the component then turns on and creates a dead short.

There are wires from each hot to ground typically. So if the voltage went above 330 volts, there would suddenly be a dead short to ground from each hot.

Then when the voltage dropped down below 330 volts, these components would "turn off' and allow the regular flow of electricity.

All this may happen in fractions of a second and you might not even notice anything going on with your electric system!

The following page shows "oscilloscope" pictures of AC house type electricity. AC is alternating current. It goes from +120 volts to -120 volts 60 times a second. Thus the little white line in the pictures going up and down. Higher up and lower down means MORE voltage.

So in the case of the first picture (Power surges), the white line going up higher/lower shows a voltage spike...

http://www.ackadia.com/computer/power-p ... oblems.php

More...

http://en.wikipedia.org/wiki/Surge_protector

[msteger]

I was at a house today that had a lightning arrestor on the panel (it said either lighting or lightning arrestor...it was all scratched up). This is the first on of these that i have seen in a panel. The one wire was loose (see picture). How do these work? And, is this how they are suppost to be installed (directly to the main feed)?

The installation is wrong for the following reasons:

The main lugs aren't listed to hold the smaller conductors.

The main lugs aren't listed to hold two sets of conductors.

The main lugs aren't listed to hold both copper and aluminum conductors together.

Of course, one of the conductors has come loose.

The arrestor leads are supposed to be as short a possible and terminate on their very own breakers, one on each pole.

I've never seen or heard of it done correctly. *Everyone* pretty much double taps them onto either the main lugs or onto the lugs of a branch circuit breaker.

- Jim Katen, Oregon

I've actually seen one installed correctly.. only once.

[John Dirks Jr]

How does one know what size breaker these devices should be connected to?

[rbaake]

Yea, I typically call out any double taps especially on SE lugs.

As for antioxidant, I point it out almost everyday. Most of homes I service are in coastal areas and salt air really seems to effect aluminum. Guess it depends on location.