24♦ The contact surface must be smooth and level. It mustalso be sufficiently strong and sturdy to avoid vibrationand shocks.♦ Make sure that the mounting is able to support theweight, especially in conjunction with external batteryunits (special accessories).♦ Set up the units so that adequate air circulation isassured. There must be at least 200 mm clearancebehind the rear fans for ventilation purposes. Do notblock the intake openings on the front and, if present, onthe side of the unit. There must be a gap of at least50 mm here.♦ External battery units must be placed on the side of theUPS system. To ensure the greatest possible mechanicalstability, do not place the external battery unit(s) aboveor below the UPS system.♦ Avoid extreme temperatures! We recommend an ambienttemperature from 15°C to 25°C in order to maximize theservice life of the batteries. Do not expose the units todirect sunlight or operate them close to other heatsources such as radiators.♦ Protect the units against external effects (in particularmoisture and dust). In this regard, please also refer to theinstructions in chapter 3, page 16 in these operatinginstructions.If you transport the unit from a cold room into a warm one, or ifthe room temperature suddenly drops, then condensation mayform inside the unit. To avoid any damage due to condensation,let the unit acclimate for 2 hours before you switch it on.