Why whole house surge protectors are not enough

Interesting!! Based on what I've read about lightning striking outdoor AC units directly I really think that it's our outdoor units, not our stereos, which need a separate panel.  That is, if I could redo my house wiring, I'd run a panel from the meter straight to the outdoor heat pumps, with their own breakers and surge protectors, and another line from the meter into the house.

I mean of course to meet code 100%.  What I'd avoid if building new is to have the electricity come inside to a service panel then back out to AC units.  As it is, any lightning striking those outside units gets to come inside before meeting a surge protector.

I understand what you’re saying Erik. You’ve given me another idea. As of right now (and as with almost any), my outdoor A/C condenser’s earth ground goes back into the house, and attaches to the panelboard’s grounding bus bar. If we’re looking at lightning protection for a condenser (if it sustains a direct hit), one would want that strike to immediately discharge into the ground, *before* hitting the circuit breaker box, and *then* discharging into the ground via the ground rod(s) feeding the circuit breaker box's grounding bus bar. For many this may not be feasible, but in my case, my ground rod is right beside my A/C condenser. While maintaining the current condenser earth ground connection, I may install another low impedance earth ground directly from the A/C condenser to the ground rod (again, OCD).

Having been a Radio Broadcast Engineer for decades, this is basically the same thing we do when grounding broadcast towers. The main ground system exists around the broadcast tower (many times incorporating a ring of ten 8’-10’ grounding rods cadwelded together), so that the strike can *immediately* discharge into the ground, *before* entering a transmitter building or studio/office building. The rest of the star ground system for the facility then feeds off of this broadcast tower base ground system.

@dpop That is an excellent idea.  As you know, for the sake of others who may read this, you may not have separate grounds, but so long as you bond everything at the same ground potential you may run multiple ground conductors to the same grounding rod(s), which probably should be plural.  

@erik_squires Yes, already aware, and yes, for the sake of others.

One other thing (that I learned in broadcast engineering): many times a lighting strike discharge does not like to take corners. Straight wires (with the least amount of bends) are always encouraged when designing grounds that will dissipate and discharge lightning strikes quickly into the ground. Also, due to the skin effect of wire at certain frequencies, and the general frequency (spectrum) of a typical lightning strike; in the broadcast world, we almost always use 3"- 5" copper strap (very low resistance with lots of surface area) when dealing with lightning and grounding.  

Just to lower the tone for a moment, I did a trip around the house and found that two of my surge suppressors were no longer suppressing anything. One replaced, one on order. Goes to show - some attention required.