Access Configuration Manual

Heat pump as using flammable refrigerants i.e. R454B or R290, it is need for safety funcon to evacuate the gas inside AHU, if the system has a leakage. It is two Gas sensors for detecon inside the AHU, supply air side and extract air side (for R290 its four gas sensors). Gas sensors is connected to the Access control unit. Gas sensor alarm forced the running mode to Gas evacuaon mode (normal speed levels) even if the running mode is stopped. Aer gas sensor mixture decreased, lower than alarm limit, Gas evacuaon mode runs in minimum 2h, than is the Gas detecon alarm possible to acknowledge and AHU can be stopped. When R290 is used, a safety damper module is used in the end of Supply air stream, and in the beginning of extract air stream, to block the air in to the building. The air going through the evacuaon damper to the air from supply air part to extract air part and then blowing out through the exhaust air.