Q. What causes an electric fence to fail?
A. The biggest cause for a failed electric fence is HUMAN!!! Most
people do not fully understand what it takes to correctly install
and maintain an electric fence. They do not understand that any
electric fence requires routine maintenance to keep adequate power
on the fence or maybe they just are too busy to take the time to do
the required maintenance.
The biggest maintenance problems are inadequate ground (poor
ground), poor connections, using wrong wire size, using too small of
an electric fencer for the job (under powered fencer), etc.
It all goes back to the “human factor”.
If you decide to use electric fences, take the time to learn how to
correctly build the fence and maintain it. Buy the correct electric
fencer for the job and read your owners manual thoroughly.
Q. What does low impedance mean?
A. In non-technical terms, low impedance means the fence charger is
designed to effectively shock through vegetation and other foreign
matters contacting the charged wire. Vegetation such as grass,
weeds, vines, etc., contacting the charged wire tend to impede or
stop the flow of electricity by “grounding out” the fence. This is a
common problem which exists on most electric fence installations.
The low impedance fencer is a solid-state capacitor discharge design
and has enough power to force the shock through vegetation. The best
low impedance fencers have an on-time of less than 100 micro-seconds
(100 millionths of a second) with a pulse rate of approximately 55
times per minute.
Q. Does Parmak manufacture low impedance models?
A. Yes. The Parmak solar model Mag 12-SP is a low impedance, UL
Q. What is Joule?
A. The joule is a measurement of heat in British Thermal Units
(BTU’s) or Foot-Pounds Energy. The distance a given weight can be
moved in a unit of time, or the amount of heat that is generated for
a specified time, equals a joule, (i.e. a joule is equivalent to
.7378 foot pounds of .0002778 watt-hours (approximately 1 watt
Q. How does the joule relate to the performance of an electric fence
A. It doesn’t. It would take a ten page letter to explain all the
factors which make an electric shock effective. The joule does not
measure the effectiveness of electric shock. The joule is a
mathematical equation of Voltage x Amps x Joule. The longer the
“on-time” of the pulse, the higher the joule rating will be and the
longer the “on-time” the less safe the fencer is to use and the less
The joule is not the correct way to measure the performance of any
electric fence charger because the joule does not consider peak
current value or “on-time” which are key factors in the
effectiveness of a fencer, therefore, the joule cannot define true
shock effectiveness or fencers safety.
What controls livestock is voltage and amperage. You must have
voltage in order to force electricity through the conductor (fence
wire) as well as vegetation touching the fence, etc., and you must
have current in order for the livestock to feel that shock. Joules
or heat has nothing to do with it.
The most effective fence charger will have the highest power
(voltage and amps) possible in the shortest, on-time possible,
thereby allowing the fence charger to develop a sharp spike which is
far more effective in controlling livestock and at the same time is
safe to use.
Example of how misleading the Joule rating is: The Parmak model Pet
Gard is a continuous current, non-pulsing type charger designed for
small animals in back yards, gradens, etc. Using the joule rating
(Voltage x Amps x Time) the Pet Gard would have an unlimited joule
rating making it the most powerful fencer, which it is not.
In summary, it is important to point out that Underwriters
Laboratories (U/L) or Canadian Standard Assoc., (CSA) do not
recognize the joule rating as a measurement when applied to electric
Q. If the joule should not be used then why do imported fencers use
the joule rating?
A. The imports use the joule rating as a marketing ploy to sell
fencers. By using the joule rating and other misleading claims they
create as much confusion as possible in an attempt to “cloud the
issue”, and cover up the true facts about what makes a fencer
What they do not tell you is that the “on-time” of their fencers are
several times longer than Parmak models which automatically gives
them a higher joule rating. No wonder they like to talk about
joules!!!! Because of this longer “on-time” the majority of
important fencers are not U/L listed (U/L limits the “on-time” of
fencers for safety purposes) and are considered by many to be
potentially dangerous to use. What you do not know CAN hurt you!!!!!
Q. Why is good ground important?
A. Regardless of make or model of fence charger, it is essential the
fencer be grounded properly. Think of an electric fence as an
independent electrical circuit. In order for the circuit to operate
properly, it must be grounded. AC models operated on poor ground
will continuously blow fuses and will eventually be damaged by a
poor ground. Battery models operated on poor ground will have little
or no shock on the fence. All models are case grounded. If you
receive a shock when you touch the fencer, this automatically
indicates poor ground. It is recommended that the higher, low
impedance models Mag 12 U.O., Mag 12 SP, M6 and S.E.3 have three (3)
ground rods to insure proper ground. Remember, poor ground costs
you. Refer to the fencer Owner’s manual for detailed grounding
Q. Can Parmak fencers be used on high tensile multi-wire fences?
A. Yes. The Parmak models mag. 12 U.O. Mag 12-SP, M and S.E. are all
high performance, low impedance, fencers specifically designed to
use on high tensile fences. The model S.E.3 is the most powerful
model, capable of charging over fifty (50) mile of fence. All four
models are equipped with Parmak’s exclusive performance meter which
tells the customer the exact condition of fence.
SPECIAL NOTE: For those customers using Poly wire or Poly tape, any
of the Parmak solid-state models can be used with this type of fence
Q. Why are AC models damaged by lightning more often than battery
A. Over 98% of all lightning damage to fence controllers comes
through the power line. The lightning may actually strike several
miles away but is transmitted through the power line and will damage
equipment connected to power line, such as televisions, stereos,
fence chargers, etc. Parmak fencers are equipped with two lightning
arrestors on the AC line. These lightning arrestors eliminate much
of the damage, however, it is impossible to stop lightning damage
100%. It is recommended whenever possible that the fencer be
disconnected during electrical storms. When it is covered by
warranty the fencer can be returned for service.
Q. Why is U/L listing important?
A. An electric fencer is different from any other electrical
appliance. All other electrical appliances are designed not to
shock, whereas an electric fencer is designed to shock. That shock
must be effective and at the same time safe. In North America (US &
Canada) there are only two accepted safety standards for electric
fencers, Underwriters Laboratories (U/L) and Canadian Standards
Association (CSA). It is important that the fencer you use be U/L or
CSA listed because this is your assurance that the fence charger has
been thoroughly tested and is completely safe to use under al
conditions. U/L listed fence chargers are subjected to very strict
safety testing. NOTE: There are many fencers on the market which are
not U/L or CSA listed and are considered potentially dangerous to
Q. Product Liability Insurance Coverage?
A. Yes, All products manufactured by Parker McCrory, are covered by
Products Liability Insurance. It is important to point out several
brands on the market do not offer products liability coverage.
Should a product’s liability claim arise from one of those fencers,
you are on own with regards to liability and any losses which you
Q. What type of fuses are used in Parmak Fencers?
A. All AC models use two, 1 amp fuses. These fuses are designed to
help protect the fencer against lightning and poor ground damage.
When replacing fuses, use (3 AG) 1 AMP fuse only. Do not use slow
type fuses or any fuse rated higher than 1 AMP, doing so will damage
fencer and voids all warranties.
Q. How do you troubleshoot a fencer?
A. Over the years it has been proven that over 95% of all problems
with electrical fencers is a direct result of poor fence
installation (i.e., poor ground, shorts on fence, weeds, etc.) and
not the fence charger.
When trouble shooting the fence, turn fence charger off and
disconnect fence from the fencer. Turn fence charger on and with a
screwdriver (with insulated handle) short across output terminal of
fencer to ground terminal. Allow a spark gap of approximately 1/16”
or 1/8” depending on model. If fencer is not working and you see a
blue spark the problem is in the fence and not the fence charger.
NOTE: if the fencer is not working at all, replace both fuses with
new (3AG) 1 AMP fuses only. If the fencer still does not operate
return it to the factory or authorized service center for service.
REMEMBER, any electric fence requires routine maintenance.
Q. Recommendations on which fencer to use under various needs.
A. The application of electric of fence varies widely from
controlling small pets such as cats, dogs to domestic livestock,
cattle, horses, hogs, sheep to controlling wild animals, deer, bear,
(elephants in Africa), etc. The model you choose will depend on the
fence construction and the animals you are controlling.
S-1 (GOOD) DF-LI (BETTER) DF-SP-LI (BEST) (all Parmak models)
These are six volt models designed to be used on clear weed free
fences. The model Q-1 is ideal for small pets, to protect gardens,
small barn lot, etc. The models DF-LI and DF-SP-LI are low impedance
and will shock through wet weeds and brush. They are designed for
small to medium size fences and is ideal for hogs, cattle, and
horses. The DF-SP-LI is solar powered.
MAG 12 U.O. (GOOD) MAG 12-SP (BEST)
These are 12 volt models designed for medium to large fences. Both
models are low impedance and will shock through weeds and brush, and
are ideal for cattle, horses, hogs, sheep, deer, etc. The Mag 12 U.O.
and Mag 12-SP can be used to control large animals and larger
pastures. The Mag 12-SP is solar powered.
This AC model is for small to medium size fences and will shock
through a medium amount of weeds, brush, etc. The FM is ideal for
hogs, cattle and horses. The FM is not recommended for sheep or deer
MARK 6 (BETTER) S.E.3 (BEST)
These are top AC models for medium and larger fences. Ideal for all
livestock or deer fences. The S.E.3 is the best choice for high
tensile fences and can charge over 50 miles. Both the M6 and S.E.3
also excellent for sheep or deer fences.
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