2215 IH 45 
6612 Harborside Drive 
3501 N. IH 35 

League City, TX. 77573 
Galveston, TX. 77554 
Georgetown, TX. 78628 

2813320511 
4097447131 
5129304000 

Fax: 2815542592 
Fax: 4097447131 
Fax: 5129304002 

Houston Fax 2813320513 
Email: afence@afence.com 
www.afence.com 
Grounding Recommendations  Installation Guide  Milage Guide
Definitions Of Terms
Low Impedance: The above Parmak models are the latest stateoftheart Low Impedance design which allows more shocking power to be delivered to the fence. Parmak fencers will effectively charge awider range of fence conditions and lengths with less power loss due to weeds and brush contacting the charged fence wire. Parmak Low Impedance fencers will shock through wet weeds and brush and will shock to end of fence.
Fence Load: Electric shock is a product of voltage and current (amps) and it is the current that provides the power of the shock that the livestock feel. Voltage provides the electrical pressure that makes the current flow. Fence load is vegetation (weeds, vines, etc.) contacting the charged wire which creates a short to ground through the weed. The more weeds touching the charged wire, the greater the fence load becomes, causing voltage on the fence to drop and current (amps) to rise. Open Circuit is when the fence charger is operating with no fence load. 500 ohm load equals approximately 5 miles of medium weeded fence. 100 ohm load equals approximately 5 miles of heavily weeded fence.
Joule Rating: The joule is a measurement of heat in British Thermal Units (BTU's) or footpounds 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 watthours (approximately 1 watt second). The joule does not measure the effectiveness or safety of electric shock. The joule is a mathematical equation of (Voltage x Amps x Time). The longer the "ontime" of the pulse, the higher the joule rating will be even though a longer "ontime" is less effective and less safe to use. It is important to point out that Underwriters Laboratories (U/L) and Canadian Standard Association (CSA) do not recognize the joule as a measurement when applied to electric fence chargers. We agree with U/L and CSA that the joule rating is not an accurate way to measure the effectiveness of any fence charger, however, we have provided the above joule ratings so you will have a basis of comparing Parmak with other brands which do rate their fencers in joules. Parmak joule ratings are based on the lowest and highest rating that model will produce based on varying fence conditions.
NOTE: Fence conditions (fence load) constantly varies 24 hours a day and there are no two fences which are the same. The joule rating of any electric fence charger constantly varies as the fence load varies. No one can tell you accurately the joule rating on your fence without actually measuring it on your fence.
How does the joule relate to the Performance of an electric fence charger?
It doesn't. It would take a ten page letter to explain all of 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 Time. The longer the" ontime" of the pulse, the higher the joule rating will be and the longer the "ontime" the less safe the fencer is to use and the less effective. 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 "ontime" 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 ontime 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 Pet Gard (model PG50) is a continuous current, nonpulsing type charger designed for small animals in backyarcts, gardens, 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 as a measurement when applied to.
Grounding Recommendations  Installation Guide  Milage Guide