15Ultra 1.54Comfortable indoor climate in high-end interiorsInstallation and operating instructions7. Waterside connection• Connect the Ultra as per the labels on the product.• Route the pipes so that no mechanical stresses are transferred to the heatexchanger and the unit can be accessed with ease for maintenance andrepair work.• Provide ventilation for the pipes on site.• Properly seal pipe connections not being used.• Important note: The heat exchanger is suitable for use with hot waterheating systems in compliance with DIN 18380. Ensure that operatingconditions and water quality conform to VDI 2035 and comply withindustry-standard installation regulations.Caution! Hold the connections on the heat exchanger with a pipe wrenchor other suitable tool when connecting the pipework.Caution! Insulate all pipes with an impermeable material on cooling units!Continue the insulation through as far as the unit.Caution! The use of flexible pipes (such as braided pipe connections,spiral or corrugated pipes) are recommended in particular when installingthe unit under a solid ceiling. When used in conjunction with appropriateshut-off valves, it is then possible to dismantle the unit relatively easilywithout needing to dismantle the fan. EC fans can only be replaced if theentire Ultra has been dismantled.8. Factory-fitted accessoriesDescription of accessories Suffix for Ultra typeFrost protection thermostat and square connecting frame . . . . . . FRepair switch . . . . . . RMonitoring thermostat with recirculating air units . . . . . . TContinuously variable power module including repair switch forUltra type ending 16 . . . . . . VKaControl recirculation air module including repair switch for Ultratype ending 16, 33 and 34. . . . . . . C1Description of accessories Suffix for mixed airunit typeDifferential pressure switch for filter monitoring . . . . . . DLimit switch, for mixed air unit . . . . . . EV 1“R 1“A330BCD35 35Ultra-Serie A B C D73 840 750 739 72984/85 1004 900 912 90496 1177 1050 1085 10771 Flow2 Return12Several combinations of components are possible e.g. …FR, DE