Panel Earth ground

So the recent topics regarding lightning and surge protection got me thinking about my HAI install.  I live just south of Tampa, which has the highest incidence of lightning in the US.
 
On my last HAI install, I ran a new AC drop directly from my breaker panel to the closet, and I used the ground lead in the AC wire to Earth the OPII panel.  I used an Elk transformer, and just connected the panel ground to the ground lead on the transformer.  It ran (and is still running today) for years without a single hiccup due to lightning.  I'm thinking of doing the same thing again.  Is this reasonable?  The OP installation manual says to use a cold water pipe or a 4-foot ground rod, but I see issues with those ideas.  I don't see a ground on the water main, and both the water main and house AC ground rod are about 40ft. away from where I'd like to install the panel.  Using a ground going to the panel seems more safe to me, in the event that there is a strike and there is current flowing in the ground.  (Everything in the house would experience the same offset, so there shouldn't be current flow between them.)  I'd install the OPII next to the breaker panel, but that's in my garage which gets painfully hot in the summer.
 
Also, I'm using shielded wire for the various zones, and I'm thinking about connecting the shields together and to this same ground at the panel.  Is this the strategy people generally use for shielded wires for the various zones?  Is there a cleaner way to connect them all, other than using a terminal block inside the panel enclosure for the drain wires?

I agree with where you are going the best strategy to prevent surges crossing through your devices is to use a single ground for everything or less effective tie your grounds together with a more preferred path.  But having multiple isolated grounds for dish, phone, cable, electric, etc (which seems to be the norm in the stix where I live) is a recipe for disaster.    
 
Also grounds are more effective the more natural earth they have around them, concrete, etc diminishes the capacity making it more likely to seek another ground.

The panel earth ground is a different consideration than the surge protector that is installed to prevent stray current from entering your building via a cable that is buried underground between two buildings. The panel earth ground is there to conduct stray current originating in the panel safely to earth rather than through a person's body to earth and the Elk installation manual requires you to isolate the panel from earth ground altogether.
 
The spd that is connected to wires in a buried cable at the entry point of a building is there to conduct excess current originating  in the external buried cable (maybe lightning) harmlessly and directly to earth rather than through your equipment to earth.
 
Mike.

As per Mike above, adding another ground to equipment inside the building can actually attract lightning and surges to the equipment where it can find another way across the equipment to earth.
 
Keep inside equipment grounded and surge protected to it's own cable ground wire to limit differential surges.
 
Use panel grounding and whole home surge protectors at the panel to limit incoming single-ended surges from coming into the house.
 
IOW: where surges can enter, get them to ground as fast as possible at the entrance. Inside the house surges created by your own equipment, clamp them to the same lines inside the same cable that feeds that equipment and/or as close to the offenders as possible.
 
When inside equipment has wiring travelling outside it becomes very complex and artsy to protect. Another matter and art.

I'm not looking at surge protection at this point - only grounding and shielding.  I don't have any buried cables, and I don't plan on any cables leaving the footprint of the house.
 
The best ground is the one which stays at a common potential with all devices and has the lowest impedance.  This is why I tied the last install to the house ground back through the breaker panel via the electrical outlet's ground pin.  It was the shortest path and was common (at the panel) with all of the other outlets.  I'm just not sure if it's a bad idea to do it this way for some other reason.  (NEC, etc.)
 
I'll be installing a whole house surge suppressor at the breaker panel in addition to the surge protection on many outlets throughout the house.

Ideally, you'd like to have the earth ground connection to have as low an impedance as possible. That means having as few connection points as possible, which would be a continuous wire from the earth ground terminal on the OP2 to the grounding electrode outside.
 
If you connect the ground terminal on the OP2 to the transformer, then you have the following connection points.  Each one increases the impedance.
 
1. OP2 earth ground terminal to wire
2. Wire to transformer ground terminal
3. Transformer ground terminal to ground pin (internal to transformer. might be 2 connections depending on how its done)
4. Transformer ground pin to outlet ground pin
5. Outlet ground terminal to cable ground wire
6. Cable ground wire to electrical panel ground bus bar
7. Electrical panel ground bus bar to grounding electrode cable
8. Grounding electrode cable to grounding electrode.
 
The best thing would be to mount the OP2 as close to your electrical service entrance as possible, so you can have as short a ground wire as possible.   Otherwise, you have to accept the trade offs of the best grounding connection vs wiring convenience.

RAL said:

Ideally, you'd like to have the earth ground connection to have as low an impedance as possible. That means having as few connection points as possible, which would be a continuous wire from the earth ground terminal on the OP2 to the grounding electrode outside.
 
If you connect the ground terminal on the OP2 to the transformer, then you have the following connection points.  Each one increases the impedance.
 
1. OP2 earth ground terminal to wire
2. Wire to transformer ground terminal
3. Transformer ground terminal to ground pin (internal to transformer. might be 2 connections depending on how its done)
4. Transformer ground pin to outlet ground pin
5. Outlet ground terminal to cable ground wire
6. Cable ground wire to electrical panel ground bus bar
7. Electrical panel ground bus bar to grounding electrode cable
8. Grounding electrode cable to grounding electrode.
 
The best thing would be to mount the OP2 as close to your electrical service entrance as possible, so you can have as short a ground wire as possible.   Otherwise, you have to accept the trade offs of the best grounding connection vs wiring convenience.

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Which is when a copper plumbing pipe starts looking like a good idea.. That is assuming that the pipe makes a full path to the earth with no breaks like a plastic water filter. I don't know if that is an acceptable practice now but it was common years ago.

Still in practice bringing the plumbing up to the potential level of the panel, to avoid voltage differences between the faucettes and the framing/floors in the home.
 
It is more about having everything metal in the house at the same potential. Now you have more of a Faraday cage and not much can bother you inside.
 
I am surprised that metal siding and roofs don't have to be grounded, yet,  as there must be a lot of induction from atmospheric discharges and charged clouds overhead with such large capacitor plates. I see houses under 230kV lines and wonder if the siding is spot welded anywhere after a few years.

mikefamig said:

The panel earth ground is there to conduct stray current originating in the panel safely to earth rather than through a person's body to earth and the Elk installation manual requires you to isolate the panel from earth ground altogether.

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I have never understood why Elk requires you to isolate the panel from ground, while HAI requires the panel to be earth grounded.   

rockinarmadillo said:

I have never understood why Elk requires you to isolate the panel from ground, while HAI requires the panel to be earth grounded.   

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Unless grounding is done properly, it can be a source of noise that can cause a whole slew of other problems.  I suspect that's why Elk doesn't recommend grounding the alarm panel.

rockinarmadillo said:

I have never understood why Elk requires you to isolate the panel from ground, while HAI requires the panel to be earth grounded.   

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Google "ground loop" and it's effect on stereo amps and speakers. i think that this is what RAL is referring to.
 
Mike.

LarrylLix said:

As per Mike above, adding another ground to equipment inside the building can actually attract lightning and surges to the equipment where it can find another way across the equipment to earth.
 
Keep inside equipment grounded and surge protected to it's own cable ground wire to limit differential surges.
 
Use panel grounding and whole home surge protectors at the panel to limit incoming single-ended surges from coming into the house.
 
IOW: where surges can enter, get them to ground as fast as possible at the entrance. Inside the house surges created by your own equipment, clamp them to the same lines inside the same cable that feeds that equipment and/or as close to the offenders as possible.
 
When inside equipment has wiring travelling outside it becomes very complex and artsy to protect. Another matter and art.

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Wow.
 
Grounding doesn't attract lightning or cause surges. The main item is to make all the connections within the house be at the same voltage potential, which doesn't insure or protect from a rising ground voltage transient.
 
The surge is not caused by anything other than a potential voltage difference. The hardware doesn't cause a surge, the transient voltage induced or directly broadcasted to a peripheral is what causes the surge.....
 
Suppression is only to bleed off dangerous or damaging transients before they get to critical components. Transients won't be caused from say, your panel seeing too much AC voltage or a supply going south (caps drying out or a supply heading south is a different discussion).
 
Elk's suggestion stems from the inherent nature of connecting an alarm panel to POTS lines and then to AC power and the inherent voltage potential differential between the two systems and the link through a EG at the panel. Generally, though required by NEC, the majority of manufacturers state to NOT ground their panels unless extra transient protection is desired.
 
The best ground location for a panel is bonded to the same EG as the electrical panel and other systems being bonded to that as well.....assuming the rod is not glazed over. Have seen it with older rods and houses that saw a couple of hits or surges, the ground essentially turned to a glass covered copper rod over time. Megger needs to be used to verify or in doubt, pull the rod.

I'm just going to do what I did on the previous install, then.  I'll use the electrical outlet ground to Earth the OPII, and everything will tie together at the panel.  I'll see what I can do to verify that there is a good Earth ground at the panel, too.
 
DEL, have you used shielded wire on installations?  Do you just tie the drain wires together at the panel and Earth them there?

Tying the shield to the EG isn't for suppression purposes, it's to drain off induced currents, but generally, they'll get tied to an EG connection within the enclosure (most should have a ground lug).

DELInstallations said:

Tying the shield to the EG isn't for suppression purposes, it's to drain off induced currents, but generally, they'll get tied to an EG connection within the enclosure (most should have a ground lug).

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Yes, exactly - I'm looking at shielding the zone wiring from induced currents.  The differential zone impedance is reasonably low with the 1K EOL resistors, but the shielding should give common mode noise a place to go.  Otherwise, the zone wires make nice, long receiving antennas! 
 
I don't plan on any additional surge protection for the zone wiring at the panel.