Only for the more subtle skills of construction burglar alarm detection
Engineering practice in the past , you will find that part of the hidden dangers exist burglar alarm works in pipeline construction. Here we are talking about is not the hidden dangers of fire hazards , but to sabotage risks. In some parts of the detector is installed , we can often see the use of PVC pipe sleeves or bare alarm detection cable , pipeline installation height is not enough manpower palpable , so these can be regarded as the system exists vandalism problems.
Some people think it is not important that the host portion of the entire system may be provided with a tamper-resistant feature, the system can react to any damage is detected . But it might work great impact on system performance , or even cause system downtime for repairs . Then the system maintenance engineers need to invest more physical and mental closer look this point of failure. Can not find the words in such a short time , for some systems will not allow the system to alert the user to arm within the specified time , because the system will think the fault has not been ruled out.
Use some of the existing projects for PVC pipe or tank guards pipeline anti-theft system , I think this is clearly wrong . While the construction or investors, this is extremely unethical . With respect to the terms of galvanized steel , PVC pipes are very vulnerable to vandalism , although its low cost , but the extreme lack of hardness index galvanized steel . From some of the media have been able to see a lot of outside contractors to install burglar alarm sensor in the picture , you can see the picture carefully studied extends from the probe out of the sheath tube is made of metal hose, a special card connector this hose is connected to the detector , the other end of the hose connected to a sealed metal over junction box, the other end is connected to galvanized steel boxes .
In the actual installation process, especially for some of the new building . In the design, installation , should fully take into account the hidden detector pipeline installation , can be embedded or embedded should be considered when the protective tube . This work can be when pouring concrete structure of the building with the civil construction unit to complete, so the entire transmission path to ensure the greatest degree of concealment. Should also consider the good of the protective tube can be easily embedded with a trunk tray feeder can be flexible for the future so that 's easy to use with threading path as a sheath tube preamplifier in every small diameter steel cable .
In the past, engineering, installation , and for the installation of an indoor wall-mounted alarm probe , given the project cost without optional mounting bracket , and even some people completely ignore the importance of the mounting bracket , causing the instability of the whole system , including increasing the difficulty of debugging , because not stand " universal " in order to adjust the characteristics of long time can not be precisely adjusted to the probe within the area to prevent detection . So sometimes this can not be omitted from the purchase price , calculate the time -consuming installation labor costs and labor costs for future maintenance , which may be far more than the intrinsic value of small parts. For a project manager is concerned , this account was able to clear enough of .
Of course, sometimes do not need to choose this installation accessories , such as : When you install an alarm detectors on both sides of the vertical angle of 90 degrees to the wall , then you can not use to the mounting member , simply install the wall on the site hammer drilled with several holes, and then the expansion of the rubber plug installed, the detector back to live with a wooden pallet stopper scored gong ribbons can be. This setup can be omitted a mounting bracket , so for indoor wall-mounted alarm sensor installations often require everyone according to their installation environment to determine whether the use of which installation method .
Section 2 : the length of the connecting cable redundancy
Redundant connection cable length
When a probe is fixed after installation , you need to do is connect the probe stripping . Then there are some people tend to ignore how to calculate the exact length of the cable should be set aside . Feeder cable is too short will cause difficulties on the debug probe , found only adjust the angle of the detector cable is too short ( excess cable has been cut ) to be necessary. The long feeder cables will shine into the detector surface cover is difficult to close , then it can only pull out the excess cable box outside the detector . But this time new problems will arise , extra cables will be exposed to security risks caused by the detector outside . When these situations arise , we can install fixed target detection and adjustment after a good azimuth angle detector, then you can probably needed to determine the actual length of the required length , remove the excess cable connections to facilitate stripping probe circuit board wiring base .
Tamper switch connections
When connected to the detector , the detector should try to tamper switch connected to the system , the benefits of doing so is to enhance the anti- destructive of the whole system . On the project has been implemented or are being implemented , the carefully according to specifications to connect tamper switch works to very little , often using a RVV4x0.5 four -core cable to connect the detector.
Meanwhile two of the core power supply for connecting the detector , the other two core switch connected to the alarm signal , rather than using the 6-pin cable to connect the switch and the power supply , the use of the remaining two cores to connect tamper switch signal . If this case is not connected to the system when each detector tamper switch , anti-theft alarm system for understanding the terms of the thieves , he can disarm the system in a period of time ( ie, non- working time ) , the easy open each detectors and their " hands and feet " , one can imagine such a safety factor is very low . Of course , connect the tamper switch can not become a finished building high-security protection , then even tamper switch will connect the cable to the host 24-hour standoff terminals up, so you can ensure the entire system equipment 24 hours in front of the probe within a tamper alert time . Here we can think of the words to the current number of burglar alarm works will seriously implement this procedure, I think this project will be rare.
Installation of pre- determined locations
Determine the installation locations of the detector, the actual project is also likely to be ignored. Anti-theft alarm detector installation process is different from the position of the selected camera mounting locations is determined , the process will not lead to false positives and false negative rates continue to rise, thereby affecting the effective use of the system. When the installation works are finding that locations is not ideal , it takes to move the position of the detector is installed you will find there are many problems.
First, the pipeline will need to move ; If you reduce the distance is also easier to shorten the pipeline , afraid afraid to extend the pipeline when the need for additional cable docking it certainly needs to face the question of extension , in order to facilitate future maintenance of the premises must be designed to a junction box, the junction box is also bound to have a hidden point . I think this problem is that the owners do not want the public to see, so advance carefully to determine the locations of the detector is critical, of course, in addition to the above problems there is a problem is that we can not ignore , and that is also easily change the installation locations the destruction of the building decoration, such as you will need to install a ceiling on the decorative surface of the detector consisting of the entire piece of plywood to move to another locations , it will be deemed to be an impossible task.