Aviary Court, Wade Road, Basingstoke, Hampshire, RG24 8PE UK
TA Series - System Design Notes
General Beam Tower System Design and Installation Notes:
a. Which Beams To Use:
TA series towers will accept all Takex Twin and Quad beam sets. These standard beam sets are supplied with plastic covers which are not required when used inside towers, and the beam metal backplates are retained in channels in the tower spine using slide-bolts and nuts. However, for preference use Takex KH series Quad beams which are designed specifically (and only) for use in beam towers. KH beams are supplied without the un-necessary covers and backplates, but are supplied with Quickfix PTKH tower mounting brackets for quick and easy installation.
b. Floor-Mounting / Concrete Base Requirements:
TAS and TAD Series floor-mount towers are supplied with side-supports which can be rawl-bolted directly onto set concrete, or mounting-base bolt-sets (CRFB) are available for setting into wet concrete (at additional cost, if required). The side supports allow the tower to be raised above ground level to accommodate uneven ground, surface cable conduits, or to avoid water-pooling etc. In firm soil floor-mounted towers up to 2m high will require a base cube of concrete with sides at least 0.4m, with cable access conduit(s) set into the base for concealed cable entry, if required. 3m towers will require a base cube of at least 0.5m sides. For unstable soil a more substantial base may be required, or for exposed / windy areas, towers can be stabilised with guy-wires. We suggest using an actual tower with side supports as a template for the groundworks, as paper templates can be re-scaled during copying or transmission which can lead to errors. Concrete bases on grass should be level with (or just below) ground level, to facilitate mowing etc. Deeply sunken bases can lead to water pooling in wet / marshy areas. Cable runs/terminations can be made directly to the towers, or to draw-pits near the towers (within the protected area) as preferred.
c. Tower Sizes And Headroom Required:
Standard towers sizes are: 1m, 1.5m, 2m, and 3m (other sizes available on request). Note that the covers for TA series towers slide from the top into retaining channels in the aluminium spine, therefore there must be headroom access space at least equivalent to the height of the tower to allow for the insertion of the tower covers. Solutions are avaialable for installations where headroom is restricted (e.g. under canopies). Please contact us for advice.
d. Beam Head Adjustment:
The beam heads can be adjusted horizontally Left 90° or Right 90° within the towers (a total of 180°). Where a double-sided tower is mounted in the corner of a site it may be preferable to fix the tower at 45° to the perimeter boundary to allow for maximum head adjustment when aligning, particularly where the boundary perimeter angle may be less than 90°. The beam heads allow for a vertical adjustment of +/-10° from horizontal to cater for slopes or uneven ground. (+/-20° vertical adjustment is possible with the PXB Series Beams)
e. Beams Near Solid Boundaries:
Where a beam 'run' is parallel to a wall / fence or other solid boundary we recommend positioning the beams away from the wall approximately the same distance as its height, to prevent it being used as a solid point to jump over the beams. e.g: if near to a 2m high wall, position the beams approx. 2m away from the wall. Alternatively, use additional beam(s) at high level to detect intruder access over the wall, or (if using wall-mounted towers) off-set ('stagger') the tower mounting positions so that the 'beams' cross in mid-air away from the towers and the wall.
f. Pressure-Sensitive Anti-Climb Switches (TAPS):
Available for situations where intruders could lay a ladder/plank or similar aid from a wall or other solid point on to the top of a tower to try to gain access, or may try to use the tower as a climbing or jumping-off point.
g. Beams Above Walls:
If mounting beams or beam towers to protect the top of a wall or fence, it is good practice to mount the beams off- set slightly to one side of the top of the wall using suitable locally-sourced bracketry, to prevent nuisance alarms from birds perching on (or animals walking along) the top of the wall.
h. Environmental Warning ('Fog Warning'):
This feature can generate a warning when the beam signal strength is reduced below a factory- preset level, and can be used to warn of the build-up of mist / fog / snow on the site (HF, AT, and KH series beams only). The Environmental Warning output contacts are separate from the main beam broken alarm contacts and can be used or not, as required.
i. Multi-Channel Units / Crosstalk:
Where beams are stacked above one another, or where multiple beam runs are in-line , or where Receivers are in close proximity, use four-channel beam units to avoid crosstalk (interference) between beams operating on the same channel. Please consult Takex for advice or assistance with system design.
Power Requirements - General Guidance:
(PSU's with Standby Batteries Recommended)
a. Beams can be powered from 12VDC or 24VDC PSUs with standby batteries (24VDC may be preferable for long cable runs where volt- drop is unavoidable). Allow 12VDC 75mA for each Transmitter (Tx) or Receiver (Rx), approx. 150mA per beam set.
b. We recommend the use of thermostatically-controlled heaters for sites where frost is anticipated. Note that 1 x Thermostat (PTS) is required per tower, and 2 x heaters (PTH) are required per beam set (1 for the Tx and 1 for the Rx). One thermostat will control all the heaters in a single tower, and one heater should be mounted immediately beneath each Tx or Rx to keep the tower cover frost-free.
c. The tower heaters (PTH) are rated at 12VDC 250mA ONLY each. See Note d. below if using 24VDC PSUs.
d. Beams and heaters can be powered from the same power supply (as long as there is sufficient current available) BUT if 24VDC power supplies are being used for the heaters, always wire 2 x heaters in series to avoid damage due to over-voltage. Please contact Takex for details on using 24VDC power supplies with PTH heaters.
e. The beam Transmitters and Receivers can be powered from separate PSUs for convenience if required - i.e. you do not have to use the same PSU to power each end of a beam set: each 'end' can use its own local power supply (this can avoid the need for long cable runs between each 'end' of a long beam run). Similarly (unlike some 'other makes' beams) you do not have to run a synchronisation (sync) cable between Tx and Rx: Takex units are self-synchronising.
f. If volt-drop problems are anticipated it may be good practice to power the beams from separate power supplies to the heaters to avoid beam power instability in cold weather. Alternatively, run separate cables to the beams and heaters from the same power supply (heaters are usually the main cause of excessive volt-drop as they require relatively high current).
g. To avoid over-running the power supplies we suggest you allow approximately 25% to 50% 'surplus current capacity' when selecting the power supplies e.g: if the system requires 12VDC 2A power, allow for a 12VDC 2.5A or 3A PSU. h. For advice on power / current requirements for specific projects, please contact Takex.
Cabling Requirements: Each Tower Will Require:
1. 12VDC Power (or 24VDC if preferred) for the beams and heaters (see Power Requirements section above).
2. An alarm output pair for each Receiver (Rx) unit in the tower.
3. An alarm output pair for the tower cover tamper switch(es).
4. An alarm output pair for the TAPS pressure-sensitive 'Anti-Climb' switch, if fitted.
5. (Optional for HF, AT, KH beams only) an alarm output pair for the Environmental Alarm ('Fog Warning') facility, if required. To economise on cables / circuits on multiple-beam sites if required, use only a small / selected sample of Fog Warning outputs.
note: Always use a separate circuit for each alarm or tamper output to assist in problem-solving / fault location.