Someone told me that surge protection only *really* works when it is at
the Main panel.
- Is that true?
- Is it worth putting in when upgrading the main panel?
- How much should it cost for a 200A supply?
It is certainly true that you want to stop these transients as soon as
possible. The panel protector works so well because it has a very short path
to ground. Make sure that is a good ground and that all of the other providers,
phone, cable etc, use it. Then your point of use protectors are only stopping
things that happen past your main. That is usually the lightning that hits the
tree in your yard.
well worth it
cost $75 to over a million buck, depends,, probably $300 area be good enuff
and might be all it takes to bump you into a secret % off your homeowners
insurance annual cost, if so, it'll pay for itself pretty quickly.
What kind of surge protecter did you put in for $50? I ask because a real
whole-house protection system from PolyPhaser or APC will run you about
$2000 for the parts alone and installation of a satisfactory ground system
is not trivial.
Obviously we are not talking about the same thing!
Mine was a small box that attaches to the breaker box I bought at HD for
$50. It has 4 wires; one to each leg, and two to the ground bus.
I am not sure how effective it is, but seemed worthwhile for $50.
I have never had a surge problem, nor have I heard of anyone having a surge
problem that would justify a $2,000 investment! Perhaps your electrical
system is different.
The quality of the protector is defined by its life
expectancy. A number defined by joules. As joules increase,
the life expectancy of a protector increases exponentially.
Minimal parameters for residential AC electric protection is
1000 joules and 50,000 amps. Most (but not all) 'whole house'
protectors meet this requirement.
The quality of a protection 'system' involves more than just
a protector. As others have noted, 'system' quality is
defined by the earthing system and how connections are made to
that 'system'. Some characteristics that make quality. Every
incoming utility has its own, separate, less than 10 foot,
dedicated connection to a single point earth ground. IOW
every earthing wire (from cable, phone, AC electric breaker
box) runs independently until all meet at that earth ground.
No splices, no sharp bends, not inside metallic conduit, and
run separated from all other non-grounding wires. That means
a grounding wire must not be nylon ty-wrapped to a phone wire
or cable wire to make it look neat. Neat tends to mean less
'quality' protection. That grounding wire should make a
bee-line right to single point earth ground.
Does that bare copper ground wire rise up from breaker box,
go over top of foundation, and then drop back down to an
earthing rod? Then the system has less 'quality'. Too long.
Too many sharp bends. That earthing wire should go right
through foundation wall to connect short to the earth ground
If a plug-in (point of use) protector does anything
effective, then that protector is already inside the
appliance. Appliances already have effective 'point of use'
protection. Protection that can be overwhelmed if the primary
and secondary protection systems are not properly installed.
The 'whole house' protector is called secondary protection.
Primary protection not properly installed is demonstrated in
Most homes have near zero protection - even with plug-in
protectors. Installing a properly earthed, $50 'whole house'
protector causes a major increase in protection. But
protection numbers exceeding 97% is not sufficient for high
reliability facilities. To get closer to 100% protection,
high rel facilities will spend an additional $1000s. For most
residences, the earth ground rod is sufficient earthing. But
to enhance that earthing, one installs Ufer grounds or halo
grounds. They cost so little if we built homes as if the
transistor exists. But we don't.
One may even put rebar mesh in the concrete basement floor
and connect that mess also to the earthing system. Purchase a
2000 joule protector for AC electric, enhance the phone
protector (provided free by the telco) with larger protector
devices, and reroute utility pipes and well water pump wire so
they too enter at the same service entrance.
Even a $50 protector is a massive improvement over what most
homes have. But don't confuse a protector with protection.
Any protector without a less than 10 foot connection to a
single point earthing ground does not provide effective
protection. Shunt mode protectors do not stop, block, or
absorb surges - as plug-in protectors would have us believe.
Protectors are effective when connecting a surge, less than 10
feet, to earth ground. Therein defines 'quality'. Not some
silly warranty that is so chock full of exceptions as to be
rarely honored. 'Quality' is first and foremost defined by
the one thing everyone forgets because it is out of sight -
rarely observed - earth ground.
To hype their ineffective protectors, some manufacturers
will vastly increase the price and offer what looks like a big
buck warranty. However lets look at one warranty exemption
Install a 'whole house' protector from Square D and the APC
warranty is void. Warranties are chock full of exceptions so
that those warranties need not be honored. Benchmarks in
surge protection (a brand name known to everyone who knows
surge protection - Polyphaser) provides no warranty. Therein
lies the trend. The smaller a warranty, then the better
'quality' that protector.
How to define quality? Quality of the protector OR quality
of the protection 'system'? Start with earth ground
inspections both for house and for utility pole. No earth
ground means no effective protection - a problem that all
plug-in protectors prefer to avoid discussing. No earth
ground means no effective protection. A problem commonly
observed among protectors that are both expensive and low
Grounding an AC power plug is not earthing. Impedance in
wire dictates that a connection from incoming utility wire to
earth ground must be short, direct, and independent. Short as
in 'less than 10 feet'. Wall receptacle is typically many
times too far away. Making matters worse, that safety ground
wire (ie romex wire) is bundled with other wires and has too
Effective shunt mode protection cannot exist at the
appliance. Obviously - all but no earth ground connection
which is why plug-in protector manufacturers avoid this entire
subject. Protection that can be effective is already inside
the appliance. That series mode and galvanic isolation inside
appliances is not overwhelmed when a 'whole house' shunt mode
protector is properly earthed.
Appliances already contain effective 'point of use'
protection that is effective IF a destructive transient is
earthed at the service entrance. Inernal protection circuits
that don't require earthing at the appliance AND assume
earthing will be performed at the service entrance. No 'whole
house' protector means appliance internal protection may be
Again, that wall receptacle has all but no earth ground -
due to excessive wire impedance and other electrical factors.
So plug-in protector manufacturer simply avoids the entire
technical discussion. They don't even claim to provide
protection from a typically destructive transient.
I have a whole house surge protector at my main panel *and* I have good
quality surge protectors on all outlets for electronic equipment.
I figure "good quality surge protectors" are those which come with a
warrantee which covers any equipment plugged into the protector. They cost
a lot, but you get what you pay for...
That statement is just TOO glib and simplified to be "true". What
seems reasonable: A surge protector in the main panel, with a good
connection to ground, is a very cost-effective first line of defense.
It might actually do all this is reasonably needed, excepting very
sensitive and very expensive equipment.
Given that it is quite cheap, and probably quite effective (assuming
you have a good ground at the main panel, without that it is probably
still somewhat effective), it seems to be a no-brainer to install it.
The ones that are easiest to install look like a 2-pole breaker, and
clip onto the distribution rails in the main panel like a breaker.
They have a ground/neutral pigtail hanging out, which you connect (via
the shortest possible path) to the ground/neutral bar. Remember, in
the main panel, ground and neutral are just about always bonded
together, with the main ground connected right there. We have a
Square D (I forget the model number) in our main panel.
That's a loaded question.
Let's look at one extreme: You have an existing main panel which has
spare space for the surge suppressor, and which has a really good
ground. You buy the surge suppressor at an electrical distributor,
through a drinking buddy who is an electrician and gets a good
discount. You install it yourself in 10 minutes. Total cost:
$50-$100 for the suppressor, and $3 for a beer for your buddy. Our
Square-D suppressor was about $70 plus tax, and I had left space for
it, and I know that there is an excellent ground right there.
Other extreme: Your main panel is stuffed to the hilt, so the surge
protector has to be in a separate box (requiring a hole to be drilled
in the main panel, and conduit fittings attached). There is no good
ground present (and never has been), and several grounding rods need
to be installed first; in extremely rocky ground this might require
trenching or drilling. And you don't want to do any of this yourself,
and hire an electrical contractor. As you should, you first pull a
building permit (in many jurisdictions, for example ours, a permit
would be required for this). At this point your are probably looking
at a few thousand $ (beginning with the permit fee of a few hundred
$), plus a visit from the building inspector. When the building
inspector comes by he finds that your whole electrical system is a
desaster waiting to happen (remember from above, it didn't have a good
ground either), and red-tags your house, causing the power company to
shut off power to you until you have the expensive contractor rewire
the whole thing. At which point you are better off mailing the keys
to the bank that holds the mortgage, declaring bankruptcy, and moving
[ For amusement, I can make the story a little nastier: Don't do like
a neighbor of ours did, when he had a "technical disagreement" with
the building inspector: He pulled out a loaded shotgun and pointed it
at the inspector. Good thing he didn't fire it. The building
inspector came back the next day, this time in the back seat of a
green car with blue lights on top, and two burly deputies in the front
seats. The relationship between applicant and building department
went down hill from there. ]
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