Nimbus Compact M NET R32 Installation Manual UK

Hydraulic connections

Hydraulic connections 4.1.1 Safety valve drain a – Make sure that the drainage pipe (1) supplied is connected to the safety valve (2) and comes out through the hole (3). The drainage pipe must be connected to the sewerage system. 2 1 3 Fig. 42 4.1.2 Minimum water content a The system must be sized for a minimum water content of at least 5 litres for every kW of rated power. If the minimum water content is not observed, the appliance is not guaranteed to function. To optimise the system’s efficiency, comfort and correct operation, we recommend: – reducing the set-point temperature of the room during winter operation when the outdoor temperature increases. – increasing the set-point temperature of the room during summer operation when the outdoor temperature decreases. Should this not be possible, we recommend increasing the water content in the system. If, for an extended period of time, the minimum thermal load is lower than the minimum power delivered by the machine, we recommend increasing the water content in the system. 4.1.3 Expansion vessel The indoor unit is equipped with an expansion vessel with a 12 l nominal capacity pre-charged to 0.1 MPa (1 bar) and with a 0.3 MPa (3 bar) safety valve on the hydraulic circuit. i The installer is responsible fro ensuring that the expansion vessel is suitably sized in relation to the system’s total water content, regardless of the valves that can exclude certain parts of the hydraulic circuit. 4.1.4 Rated and minimum flow rate The minimum flow rate must always be guaranteed in all operating conditions. Model NIMBUS M EXT R32 35 M NIMBUS M EXT R32 50 M NIMBUS M EXT R32 80 M & M-T NIMBUS M EXT R32 120 M & M-T NIMBUS M EXT R32 150 M & M-T Nominal flow rate [l/h] Minimum flow rate [l/h] Flow meter ON threshold [l/h] 600 430 390 860 430 390 1200 600 540 1550 770 702 1900 940 852 26 / EN

Hydraulic connections 4.1.5 Available pressure Hydraulic circuit Make sure that the available pressure is not lower than the head loss of the entire hydraulic system. The curves in the pictures below shown the available pressure on the flow from the outdoor unit. NIMBUS M EXT R32 kPa 90 80 70 60 50 40 30 20 10 1 0 0 500 1000 1500 2000 2500 3000 3500 Fig. l/h43 1 35 M - 50 M 2 80 M - 80 M-T 3 120 M - 120 M-T - 150 M - 150 M-T It is possible to install a supplementary circulator pump if the one supplied is not powerful enough. For the electrical connections, refer to the paragraph "Electrical connections". a If thermostatic or zones valves are installed on all terminals, mount a by-pass to guarantee the minimum operating flow rate. Consult the table in the paragraph “Rated and minimum flow rate”. 2 3 Indoor unit head loss kPa 45 40 35 30 25 20 15 10 5 0 0 500 1000 1500 2000 2500 3000 l/h Useful head 1 zone Fig. 44 kPa 90 80 70 60 1 50 40 30 20 10 0 0 500 1000 1500 2000 2500 3000 3500 l/h 1 Zone 1 Fig. 45 It is possible to install a supplementary circulator pump if the one supplied is not powerful enough. For the electrical connections, refer to the paragraph "Electrical connections". a If thermostatic or zones valves are installed on all terminals, mount a by-pass to guarantee the minimum operating flow rate. Consult the table in the paragraph “Rated and minimum flow rate”. DHW circuit The head loss of the primary heater was tested in accordance with the BS EN 12897:2016 standard and is equal to 3 kPa. EN / 27