Last year our HVAC repair tech recommended that we should get a surge
suppressor installed on our furnace/ac unit to prevent damage that
might be caused by power sikes or electrical storms.
No one else I have talked to in the neighborhood has one of these
Is it soemthing I should be concerned about?
Surges that may overwhelm protection already inside all appliances
(including the furnace) may occur typically once every seven years. A
number that can vary significantly even within same town due to
variables such as geology. A survey of the neighborhood may learn
Do you install a $100 protector for the furnace? Or do you install
something so that everything - including furnace - is protected. When
is your smoke detector most important? Maybe during events that
create surges. What protects that smoke detector?
This solution has been standard even in telephone exchanges for what
- 100 years? Standard in commercial broadcasting, 911 emergency
response centers, etc. In no case is a surge protector called
protection. A surge protector is the device that 'connects to'
protection. Protection is earth ground.
Ben Franklin demonstrated the concept in 1752. Lightning obtained
earth ground destructively via church steeples. How did Franklin
divert a surge so that a steeple was not damaged? Lightning rod
connected to protection. That protection is earth ground.
Lightning striking a utility wire down the street can be a direct
strike to every household appliance including furnace, smoke
detectors, and bathroom GFCI. How is protection installed? Just like
Franklin's lightning rod, earth a surge before it can enter the
building. One protector connected 'less than 10 feet' to an upgraded
single point earth ground does what your telco installs to protect
their computer. Their computer is connected to overhead wires all
over town. Do they put a protector adjacent to the computer? Of
Every incoming wire in every cable must connect to earth ground.
Some cables such as cable TV and satellite dish are earthed only by a
ground block and wire. Others, such as telephone and AC electric,
require a protector to make a 'less than 10 foot' connection. IOW one
'whole house' protector for about $1 per protected appliance verses
how much for that furnace protector?
This was long. Many just have trouble learning that earthing - not
the protector - is protection. Many assume a protector will somehow
stop or absorb what even three miles of sky could not. And yet that
is what the protector adjacent to the furnace would do to be useful.
That furnace protector also does nothing for smoke detectors,
dishwasher, or bathroom GFCIs.
How to installed effective protection? First, building earthing
must be upgraded to and exceed post 1990 NEC requirements. IOW all
incoming utilities must be earthed to the same electrode (ground
rod). Earthing wires to that electrode must have no sharp bends, be
separated from other non-earthing wires, no splices, not inside
conduit, and all meet as the same earthing electrode.
Second, for utilities that require earthing via a protector,
manufacturers with responsible names such as Square D, GE, Leviton,
Cutler-Hammer, Intermatic, Siemens, etc manufacturer a 'whole house'
protector. Protector must exceed 1000 joules and 50,000 amps.
Protectors has a dedicated wire for that essential ('less than 10
foot') earthing connection. Some are sold for less than $50.
Names such as APC, Tripplite, Panamax, and Belkin are not listed.
Their protectors don't even have a dedicated earthing wire. How would
their products earth as Franklin demonstrated in 1752? Protectors
without that earthing wire quietly don't claim to protect from the
typically destructive surge - one that may overwhelm protection inside
Separation between the protector and furnace is part of a protection
'system'. But more important, distance to earth ground must be as
short as practical. That means an earthing wire from breaker box,
over top of a foundation, then down to an earthing electrode, is too
long. That wire must route through the foundation and down to
earthing electrode - short distance and no sharp bends is important.
What will a protector at the furnace do? What is the shortest path
to earth? If through a furnace, then the protector may have
compromised protection that is already inside that furnace.
Do not yet let anyone promote a protector as protection. Protection
is earthing. A protector is simply a connection to earthing. But if
that earthing connection is too long, then the protector may earth,
destructively, through and adjacent electronics such as a furnace.
Your telephone also needs a 'whole house' protector. Did you know
the telco installs one for free? Why? Because a 'whole house'
protector is so inexpensive and so effective. But again, you are
responsible for providing earthing. Is that telco protector connected
short to the same earthing electrode used by AC electric, cable TV,
etc? If not, then you still do not have protection.
If not obvious, most important component in this (your 'secondary')
protection system is the quality of and short connections to a single
point earth ground. Yes - 'secondary'. Also inspect your 'primary'
An industry professional demonstrates the concept in an application
note. All incoming cables connect to a single point earthing
(directly or via a protector) before entering the building. Surge
protection required even on underground cables:
A protector will only be as effective as its earth ground. We earth
so that a destructive surge, maybe once every seven years, does not
enter a building. Therefore protection already inside all appliances
(and the furnace) will not be overwhelmed.
There are earth ground, digital ground, safety ground, a ground
between audio components, floating ground, analog ground,
counterpoise, equipment ground, and ground inside a mains breaker
box. Why a ground wire with no sharp bends, no splices, and not
inside conduit? Because ground even at opposite ends of a wire is
Also noted were surges made irrelevant by protection inside the
furnace controller. Phase to phase surges are irrelevant AND made
even less problematic by a single 'whole house' protector that earths
typically destructive surges. Protection already inside a furnace
controller and other household appliances is not overwhelmed.
Was that post long? Well proven technology is little understood
even by electricians if only trained in safety codes - not in the
radio frequency energy so common in typically destructive surges.
Surge protection involve electrical concepts often not taught to
electricians. Note referenced to impedance which is why wire length
(not wire gauge) is important.
A furnace protector will only be as effective as its earth ground
which is why superior protection is installed where surges would enter
a building. Earthing - not a protector - is the protection. Which
ground is relevant? In the US, the important ground is a single point
Surge suppressors are normally use across the contacts
such as relays contactors and solenoids, purpose of surge
suppressors is to limit reveres voltage BkEMF and to limit
arcing across the contacts lengthen life of the item and to
limit noise on electrical lines. suppressors can help incase
of lighting but very much is limited to that, how to limit damage
to you appliance from the storms, some one around the
Allentown PA. can tell you that only sure way disconnect all.
good luck Tony
Snubber circuits are not surge protectors. Arcing only creates
noise and may harm contact life expectancy. These are not surges.
Your telco, commercial broadcasters and 911 emergency response
center install a 'whole house' type protector AND earthing so that
direct lightning strikes never cause damage. Your telephone Central
Office may see hundreds of surges during just one thunderstorm - being
connected to overhead wires all over town - as even demonstrated by
1950 and 1960 Bell System Technical Journal papers. How often have
you been without phone service for 4 days while that computer is
replaced? Surge protection is installed for direct lightning strikes
- also making lesser transients irrelevant. Anyone who is suffering
appliance damage due to lightning should look at themselves as reason
that a protector and sufficient earthing was not installed.
Allentown, being an old industrial town, has many buildings with
earthing that does not even meet post 1990 NEC requirements. No earth
ground means no effective protection. Earthing that must exceed code
requirements. Those who did not upgrade their earthing or thought
some magic plug-in protector would protect them must then proclaim,
"Nothing can protect from lightning". So why do phones work just fine
all through and after the T-storm? Protection from lightning does
work when properly located, sized, and earthed.
A 'whole house' protector for even less than $50 is sold in Lowes
and Home Depot. Protectors that also include the essential and
dedicated earthing wire.
Snubber circuits are for noise. Noise voltages are so low that
surge protectors would completely ignore those tiny spikes. Tiny
snubbers are not surge protectors.
Go radio shack buy MOV.
Also buy fuse block--MOV go in line just afer the fuse block.
Could be saves this your ass inna one heartbeat.
Much added to the gleeful situation if /when the lightening actually hits
and all your fucking lowlife neighbors suffer bigtime wherein all you need
to do is you have to replace a fuse snip out the cooked MOV.
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