Page 12Chapter 2: Installing and Maintainingi-on10Planning the installationChoosing the installation locationsWhen planning the installation, consider the following recommendations concerning thelocations of where to install the control unit and other devices.Control unitThe control unit must be located: Within the protected area (but not in an entry or exit zone). Upright (battery at the bottom) on a wall or other flat surface to discourage tamperattempts from the rear. Out of sight of potential intruders. Where maximum cable distances will not be exceeded (see page 16).Keypads and proximity readersKeypads and proximity readers should be located at a convenient height.Keypads must be within the area protected by the intrusion system and ideally out of sightof potential intruders.Proximity readers or any keypad containing a proximity reader must not be located: Within 1 metre of another proximity reader (including one located within anotherkeypad). Behind a door, coat rack or other covering.External sirenThis must be located out of reach of intruders and vandals, but must be easily visible formaximum deterrence.Checking power availabilityEN50131-1 or PD6662 Grade 2 requires the backup battery to be able to power thesystem for at least 12 hours. The duration must include two 15-minute periods in alarm.You must make sure that:a) The control unit's 1.0A power supply has sufficient capacity to power allconnected devices. 180mA is reserved for battery charging.b) The backup battery can provide sufficient power in the event of a mains failure.If there is insufficient power available from the control unit or backup battery, consider theuse of additional power supplies.