Faq’s

Points To Consider


Text in italic square brackets “[ ]” indicate our proposal.

 

 How many strands are live? 

[All Strands]

(Wall top fencing has only three live strands & half of the full height fencing is dead earth strands)

Conventional electrifiers are single output units that need to be referenced to Earth – a legacy from the agricultural beginnings of this technology.  This means that fencing strands must be arranged alternately Live-Earth-Live-Earth… to maximise shock potential and short-circuit detection probability.

Earth strands are dead with no shock capability, but indispensable in conventional electric fencing, resulting in up to half the fence consisting out of dead strands!

 

How many strands are dead earth wires, with no shock capability? 

[None]

(Up to half if the strands are dead earth strands)

For conventional systems to work properly every Live wire has to be accompanied with a dead earth strand; thus at least half of the fence will be dead strands.

 

Are the top and bottom strands always live at any location around the perimeter? 

[Yes]

(possibly)

For obvious reasons the top and bottom strands of a fence must have shock potential.  A point to look for is where a fence steps; take note if the top strand is jumped to the bottom strand – in the case of conventional systems, the top strand will end up a dead earth strand!

 

 Which adjacent stands will produce an alarm when shorted together?

  [All Strands]

(Due to strand resistance alarm function is unpredictable)

Some installers configure fencing strands with adjacent strands at the same potential.  This will not result in an alarm if these strands are shorted.

 

 How many strands are monitored for cutting?

[If divisible by Four ALL, else all but two.]

(Only the live strands are monitored for cutting – wall top only two of the five – top and bottom)

Generally up to half (only the Live strands), unless these are connected in parallel, in which case all the parallel strands must be cut to set off an alarm.  Cut strands do NOT necessarily fall onto the next lower strand, as some may lead you to believe, especially if the looping at a straining post is cut off first!

 

Do you have strands connected in parallel? 

[No]

(Not checked)

Especially with thin stainless steel wire and long fences, installers tend to connect strands in parallel to counteract volts drop due to high resistance.  Strands in parallel are bridged and will only result in an alarm if they are all cut.

 

How many electrical loops are monitored for cutting?

[Two Individual High Voltage Circuits]

(only one)

Conventional electrifiers have only one Live output and therefore results in only one circuit being monitored.  Some systems have earth strand monitoring, however, not used often.

 

Do you maintain circuit continuity to detect cutting on sliding and/or swing gates?

[Yes with flexible cable or Chain sliders]

(NO and the emergency gates can be rolled open by pushing the gates to one side) ( also gate connections heath robinson!)

Connections to sliding gates are notoriously troublesome; even patent devices are unreliable and expensive, hence, gates are generally connected as spurs (with no cut detection)

Will I be able to hear the noise the unit makes in the living areas of my house?

Be sure to locate electrifier units away from living areas as generally they generate some level of noise.

 

Do you have a remote control facility that may be installed next to my Alarm keypad?

[Yes]

(NO – electrifiers are in the guard house and long high tention cables are installed to the remote zones – this is flawed as induction between these cables will cause the system to not “see” a cut wire)

Remote monitor facility does not require heavy cables to be connected and can therefore be more conveniently situated in places other than utility areas.

 

Will I be able to see at a glance if the fence is running at full capacity?

[Yes]

(NO)

Most systems are not very user friendly with only rudimentary indicators that even stumps technical minds.

 

Guarantee period on installation? 

[Two years]

 

Guarantee on equipment? 

[Three years]

Are the fence posts Galvanised & Epoxy coated?

Epoxy coatings should only ever be seen as an aesthetic product as it is not a good rust inhibitor.

 

Will the posts be mounted against, or on top of brick walls?

 

What is the probability of raising an alarm when something (like a car mat) is placed on the strands?

(Brackets can be easily bent down for easy access without alarm)

It is important to understand that when a weight is placed on fencing strands, their location in relation to each other should be such that they should in all likelihood come together in order to cause a short-circuit and thereby raise an alarm.  Thus, at least some strands in a fencing structure must be vertical relative to each other (opposing polarities that is!).

 

If ferrules are used for connecting wires, how do you prevent electrolysis between unlike materials?

Often an oversight, when dissimilar materials are used.  Ferrules make for good and neat connections – but only in the short term.  Soon electrolysis sets in that speeds up corrosion.  A green coating on the ferules is an early telltale.

 

Have you considered structures in neighbouring properties that may assist an intruder?

(especially the one corner –SE- one can simply stand on the neighbour’s wall & step over)

Walls intersecting the perimeter, neighbouring structures and trees must all be carefully considered to ensure an intruder cannot easily get to a position where he can simply step over.

 

If an angled fence is offered:

This may “LOOK” more “secure-apparent” but, due to the general light materials used for electric fence structures, they are easily bent a bit further without the strands coming in contact with each other to raise an alarm.  (Half of the bending is done already!!)  Not only unsightly but much less secure as well!  Rather consider a “T” type structure.

 

What specific arrangement do you suggest at corners?

Corners, steps and gates are the main construction headache areas.  Fences at angles other than plumb generally end up looking like porcupine nests.

 

What about the angled fencing at the gates?

If you opt for an angled fence, consider how this will work at gates.  Generally, due to obvious snagging complications, perceived security advantages falls by the way side and gates are left straight up.  As a result, the installation ends up even more untidy with no security advantage.

 

IF YOU ARE OFFERED MORE THAN ONE ZONE:

 

What happens to the zones when one energiser is switched off?

Multiple zones should always be done with individual and independent electrifiers.  With single electrifier multi zone systems, the entire fence is switched of when work is done to one zone.

 

What happens to the other zones when there is a short from the High Voltage line to earth in one zone (or if all the strands are compromised – in Zone 1 for instance)

 

Individual electrifiers for each zone have shown to be the most reliable, simplest to maintain with most options/likelihood to remain functioning in adverse conditions.